Exam 1 Flashcards
What is microbiology?
The study of living things (biology) at microscopic level (cannot be seen with naked eye).
Size of organisms studied in microbiology
10 -6
Microbiology is also the study of what non-living organisms?
Viruses and prions and the immune system
Branches of study of microbiology
Bacteriology
Mycology
Parasitology
Immunology
Virology
Molecular biology
What is bacteriology?
Study of bacteria
What is mycology?
Study of fungi
What is parasitology?
Study of parasites, usually single or multi-celled eukaryotes
What is immunology?
Study of immune system
What is virology?
Study of non-living organisms called viruses
What is molecular biology?
Study of DNA and how molecules inside a cell function
Anton von Leeuwenhoek
Discoveries that led to the invention of the first light microscope. Made over 400 microscopes with natural light source. Viewed the first microorganisms he called “animalcules.”
Animalcules
Anton von Leeuwenhoek’s name for the first microorganisms that he viewed under his primitive microscopes.
First person to view living organisms
Anton von Leeuwenhoek
Francesco Redi
Maggots on meat experiment. First time he used a sealed flask and open flask and proved that maggots come from flies. Second time he used a gauze-covered flask and open flask and proved that maggots come from flies.
The man who showed that complex (large, multi-cellular) organisms do not originate through spontaneous generation.
Francesco Redi
Performed a second experiment with flasks and maggots in an attempt to please critics to disprove spontaneous generation.
Francesco Redi
Spontaneous generation
The theory that living organisms can originate from non-living things.
Biogenesis
The theory that living organisms must originate from other living organisms.
The theory that living organisms can originate from non-living things.
Spontaneous generation
The theory that living organisms must originate from other living organisms.
Biogenesis
Louis Pasteur
Disproved theory of spontaneous generation and developed process of pasteurization.
Louis Pasteur and spontaneous generation vs. biogenesis experiment used what?
Straight necked flasks and S-shaped necked flasks.
In Louis Pasteur’s spontaneous generation/biogenesis experiment, whose work did he support?
Francesco Redi
What theory did Louis Pasteur’s experiments using S-shaped necked flasks disprove?
Spontaneous generation
Ignatz Semmelweis
Germ theory and aseptic technique
In what type of school was Ignatz Semmelweis at physician at?
Obstetrics school
What were the physician students doing before they worked with pregnant women that led to the germ theory?
Dissecting cadavers and then attending to pregnant women.
Who discovered the germ theory because of a higher rate of post-operative infection in pregnant women?
Ignatz Semmelweis
What was happening to the patients of physician students that led to the germ theory/aseptic technique?
High rate of post-operative infections in pregnant women when tended to by physician students who had come from cadaver lab as opposed to nursing students who had not.
Who theorized that physician students were transferring something from cadavers to the patients that they were treating that caused infections?
Ignatz Semmelweis
Who suggested that physician students wash their hands after cadaver lab and before they tended to patients?
Ignatz Semmelweis
What happened to the aseptic technique recommendations that Ignatz Semmelweis suggested?
They were largely rejected by physicians at the time for lack of a model.
Joseph Lister
Based on Semmelweis’ work, developed the idea of aseptic surgery.
Who sterilized his surgical tools and the site of surgery to prevent infection?
Joseph Lister
What did Joseph Lister sterilize his surgical tools and the surgical site with?
Carbolic acid (Phenol)
What did Joseph Lister use phenol for?
Sterilize surgical sites and surgical tools.
What is another name for carbolic acid?
Phenol
What is another name for phenol?
Carbolic acid
Germ theory
Theory of disease that states that infections are caused by microorganisms.
Theory of disease that states that infections are caused by microorganisms.
Germ theory
What is disease?
Any change from a state of health.
Theory of disease that states that infections are caused by microorganisms.
Germ Theory
Who hired Louis Pasteur and for what reason?
Brewers hired Louis Pasteur to find out how to prevent their products from spoiling.
Why were alcoholic products spoiling when Louis Pasteur was hired to solve the problem?
While yeast ferments sugars to alcohol in the absence of oxygen, bacteria ferment sugars to vinegar in the absence of oxygen thereby spoiling the product.
What did Louis Pasteur do to prevent spoilage in products made by brewers?
He developed pasteurization.
What is pasteurization and who developed it?
Pasteurization is the process of heating a beverage enough to kill the microorganisms after fermentation is complete before spoilage can occur. Developed by Louis Pasteur.
After pasteurization, what is required to prevent spoilage until the beverage is opened?
The package must remain sealed.
Louis Pasteur developed what process and disproved what theory?
Pasteurization and spontaneous generation
What two men were involved in germ theory and aseptic technique?
Ignatz Semmelweis and Joseph Lister
Which man, Ignatz Semmelweis or Joseph Lister, was largely discredited for his theory for lack of a model?
Ignatz Semmelweis
Edward Jenner
Developed vaccination
What disease did Edward Jenner inoculate a child with to prevent small pox?
Cow pox
The inoculation with cow pox prevented what disease?
Small pox
What did Edward Jenner call the concept of administering a vaccine to confer protection?
Immunity
What is vaccination?
The process of conferring immunity by administering a vaccine.
The protection afforded by vaccination
Immunity
What is a vaccine?
A preparation of killed, inactivated, attenuated or an otherwise relatively benign organism or antigen associated with that organism.
A preparation of killed, inactivated, attenuated or otherwise relatively benign organism or antigen associated with that organism is called?
A vaccine
What are the forms of a microorganism that can be used for a vaccine?
Killed, inactivated, attenuated or benign
Alexander Fleming
Discovered penicillan
What was the first antibiotic?
Penicillin
What were Alexander Fleming’s plants contaminated with?
Penicillium chrysogenum fungus
What did Alexander Fleming observe in bacterial colonies?
He observed that bacterial colonies could not grow near the fungal colony, Penicillium chrysogenum, and surmised that the fungus was making a substance that prevented the growth of the bacteria.
Who observed that a fungus was making a substance that prevented the growth of the bacteria.
Alexander Fleming
What is penicillin?
The first antibiotic discovered by Alexander Fleming
Who isolated a colony of fungus and named it penicillin?
Alexander Fleming
What are antibiotics?
Molecules that specifically inhibit the growth of or kill bacteria.
What are molecules that inhibit the growth of or kill bacteria called?
Antibiotics
What discovery was Rosalind Franklin involved in?
Discovery of the double-helical structure of DNA
What discovery was Francis Crick involved in?
Discovery of the double-helical structure of DNA
What discovery was James Watson involved in?
Discovery of the double-helical structure of DNA
Whose work did James Watson and Francis Crick draw from?
Rosalind Franklin
What technology led to the discovery of the structure of DNA?
X-ray crystallography data generated by Rosalind Franklin
Why was the discovery of the structure of DNA important?
Allowed an understanding of how DNA can store genetic information and can be replicated.
What technology allowed an understanding of how DNA can store genetic information and can be replicated.
X-ray crystallography
Whose data did Francis Crick and James Watson use?
Rosalind Franklin
What are
Bacteriology
Mycology
Parasitology
Immunology
Virology
and Molecular biology
branches of?
Microbiology
What metabolic process performed by microorganisms is useful to make foods and beverages?
Fermentation, the breakdown of sugars to alcohol or other organic molecules
What does alcohol fermentation produce?
Yeast cells make alcohol from sugar with the byproduct of carbon dioxide to make alcoholic beverages and leavened bread.
Bacteria also use sugar to make vinegar that is used in sauerkraut, kimchi, yogurts and cheeses.
The process of breaking down sugars into acids or alcohol in anaerobic environment is called?
Fermentation
What organisms perform fermentation?
Yeasts, molds, and bacteria
Four foods that microorganisms make?
Yogurt, cheese, kimchi, sauerkraut
Carbon cycle
Larger carbon-containing molecules are broken down to carbon dioxide in cellular respiration and fermentation. CO2 is converted into larger organic molecules in photosynthesis.
The cycle where larger carbon-containing molecules are broken down to carbon dioxide in cellular respiration and fermentation and CO2 is converted into larger organic molecules in photosynthesis.
Carbon cycle
What is produced in the carbon cycle that is reused?
Carbon dioxide
In what cycle does photosynthesis recycle the byproduct of carbon-containing molecules broken down by cellular respiration and fermentation?
Carbon cycle
What are the byproducts of cellular respiration?
Carbon dioxide and water
What are the byproducts of photosynthesis?
Oxygen and glucose
What are biogeochemical cycles?
Cycling of vital elements that are essential for living organisms.
What is the cycling of vital elements that are essential for living organisms called?
Biogeochemical cycles
Oxygen cycle
Oxygen is converted to water in aerobic cellular respiration while water is converted to oxygen by organisms that perform photosynthesis.
In what cycle is oxygen converted to water in aerobic cellular respiration while water is converted to oxygen by organisms that perform photosynthesis.
Oxygen cycle
While multicellular organisms are capable of cellular respiration, fermentation and photosynthesis, microorganisms are responsible for a significant amount of which cycles involved in these functions?
Oxygen cycle, carbon dioxide cycle, nitrogen cycle.
Nitrogen cycle
Nitrogen-containing molecules are broken down on their way to cellular respiration or fermentation.
The cycle where nitrogen-containing molecules are broken down on their way to cellular respiration or fermentation.
Nitrogen cycle
Denitrification
Microorganisms reduce nitrogen-containing compounds to gaseous nitrogen (N2), a type of anaerobic cellular respiration performed only by microorganisms.
Process by which microorganisms reduce nitrogen-containing compounds to gaseous nitrogen (N2).
Denitrification
A type of anaerobic cellular respiration performed only by microorganisms.
Denitrification
Aerobic or anaerobic?
Cellular respiration
Fermentation
Photosynthesis
Nitrogen fixation
Cellular respiration - Can be anaerobic or aerobicc
Fermentation - Can be anaerobic or aerobic
Photosynthesis - Can be anaerobic or aerobic
Nitrogen fixation - anaerobic
Nitrogen fixation
Conversion of N2 into larger nitrogen-containing molecules that is performed only by microorganisms.
Conversion of N2 into larger nitrogen-containing molecules that is performed only by microorganisms.
Nitrogen fixation
Bacteria that often form symbiotic relationship with legumes?
Rhizobium
Beans, peas and clover are what type of plant?
Legumes
Rhizobium
Genus of bacteria that often form symbiotic relationship with legumes and is responsible for converting gaseous N2 from the atmosphere into nitrogen that can be used by other organisms.
Bacteria responsible for converting gaseous N2 from the atmosphere into nitrogen that can be used by other organisms.
Rhizobium
Element required for organisms to synthesize the nitrogenous bases found in DNA and RNA
Nitrogen
Element required for organisms to synthesize the amino group found in all amino acids.
Nitrogen
For what process is nitrogen required?
Required for organisms to synthesize the nitrogenous bases found in DNA and RNA and the amino group in amino acids.
Required for organisms to synthesize the nitrogenous bases found in DNA and RNA and the amino group in amino acids.
Nitrogen
Recombinant DNA is used in what processes?
To insert a gene into bacterial or other cells to make large amounts of a protein
or
To insert a gene into bacterial cells, plants and animals to give them novel properties (to make transgenic organisms).
What is recombinant DNA?
Technology that recombines DNA from different sources into one molecule
Technology that recombines DNA from different sources into one molecule is called…
Recombinant DNA
Inserting a gene into bacterial or other cells to make large amounts of a protein or inserting a gene into bacterial cells, plants and animals to give them novel properties (to make transgenic organisms) are processes that use what technology?
Processes that use recombinant DNA
Proteins made by bacterial cells through recombinant DNA can be isolated and used for what applications?
Medical, industrial and others applications (like enzymes in laundry detergent)
Enzymes used in laundry detergent and other medical and industrial applications are created using what technology?
Recombinant DNA
What technology creates proteins that can be isolated and used in various industrial, medical and other applications?
Recombinant DNA
Where do the bacteria Thermus aquaticus live?
Hot springs
What species of bacteria live in hot springs?
Thermus aquaticus
What temperature does Thermus aquaticus live in?
70 degrees C, 158 degrees F
What is stable in the species of bacteria called Thermus aquaticus?
The enzymes, specifically DNA polymerase.
What does thermostable mean?
Function at relatively high temperatures.
What is a species of bacteria that is thermostable?
Thermus aquaticus
What is the term when a microorganism is able to function at relatively high temperatures?
Thermostable
What is the thermostable enzyme in Thermus aquaticus that is used to determine nucleotide sequencing of a DNA molecule?
DNA polymerase
What is DNA polymerase from Thermus aquaticus used for?
Used for the polymerase chain reaction (PCR), a process that amplifies DNA sequences and DNA sequencing, which is used to determine the nucleotide sequence of a DNA molecule.
The polymerase chain reaction (PCR), a process that amplifies DNA sequences and DNA sequencing, which is used to determine the nucleotide sequence of a DNA molecule requires what enzyme from Thermus aquaticus?
DNA polymerase
What is the polymerase chain reaction (PCR)?
The process that amplifies DNA sequences and DNA sequencing, which is used to determine the nucleotide sequence of a DNA molecule.
What process is used to determine the nucleotide sequence of a DNA molecule.
Polymerase chain reaction
In polymerase chain reaction (PCR) what does the DNA polymerase from Thermus aquaticus assist with in determining nucleotide sequence of a DNA molecule
Amplifies DNA sequences and DNA sequencing
What is Agrobacterium?
A genus of bacteria that injects DNA into plants as part of its life cycle.
A genus of bacteria that injects DNA into plants as part of its life cycle.
Agrobacterium
What is Agrobacterium used for?
To introduce recombinant DNA into plants to make transgenic organisms.
What genus of bacteria is used to introduce recombinant DNA into plants to make transgenic organisms?
Agrobacterium
What is Bacillus thuringensis?
A species of bacteria that produces a protein (the BT protein) that kills caterpillars that can be cultured and sprayed on crops as a natural pesticide.
A species of bacteria that produces a protein (the BT protein) that kills caterpillars. It can be cultured and sprayed on crops as a natural pesticide.
Bacillus thuringensis
The protein that can be cultured and sprayed on crops as a natural pesticide against caterpillars.
The BT protein
What species of bacteria does the BT protein come from?
Bacillus thuringensis
What is the BT protein?
The protein from the species Bacillus thuringensis that can be cultured and sprayed on crops as a natural pesticide.
The gene for the BT protein has been isolated and used to make transgenic BT corn which resists what type of pest?
Caterpillars
How are caterpillars prevented from attacking corn?
The gene for the BT protein produced by the species Bacillus thuringensis is used to make transgenic BT corn that is caterpillar resistant.
Prokaryotic vs. eukaryotic cell
Typical size:
Nucleus:
Membrane-bound compartments or organelles:
Flagella:
Cell walls:
Ribosomes:
Chromosomes:
Cell Division method:
Sexual recombination:
Prokaryotic vs. eukaryotic cell
Typical size: 0.2 - 2.0 μm / 10-100 μm
Nucleus: No membrane-bound compartment that contains DNA / True membrane bound nucleus
Membrane-bound compartments or organelles: Absent / Present
Flagella: Simple, made from two protein building blocks (flagellin) / complex, made from microtubules in 9+2 pattern
Cell walls: Present, chemically complex / Chemically simple when present, absent in others
Ribosomes: Smaller 70S / Larger 80S
Chromosomes: Usually 1 circular without histones / Multiple chromosomes with histones
Cell division method: Binary fission / Mitosis
Sexual recombination: Horizontal gene transfer (so no sexual recombination) / Meiosis
Name the three domains.
Domain Archaea
Domain Bacteria
Domain Eukarya
Archaea, Bacteria and Eukarya represent the three what?
Domains
Of Domain Archaea list:
- Type of cell
- Cell wall characteristics
- Antibiotic sensitivity
Domain Archaea
- Type of cell: Prokaryotic cells
- Cell wall characteristics: Complex cell walls without peptidoglycan
- Antibiotic sensitivity: Not sensitive
Which domain has the following characteristics:
Type of cell: Prokaryotic cells
Cell wall characteristics: Complex cell walls without peptidoglycan
Antibiotic sensitivity: Not sensitive
Domain Archaea
Of Domain Bacteria list:
- Type of cell
- Cell wall characteristics
- Antibiotic sensitivity
Domain Bacteria
- Type of cell: Prokaryotic cells
- Cell wall characteristics: Complex cell walls with peptidoglycan (with few exceptions)
- Antibiotic sensitivity: Sensitive to antibiotics
Which domain has the following characteristics:
- Type of cell: Prokaryotic cells
- Cell wall characteristics: Complex cell walls with peptidoglycan (with few exceptions)
- Antibiotic sensitivity: Sensitive to antibiotics
Domain Bacteria
Of Domain Eukarya list:
- Type of cell
- Cell wall characteristics
- Antibiotic sensitivity
Domain Eukarya
- Type of cell: Eukaryotic
- Cell wall characteristics: May or may not have cell wall
- Antibiotic sensitivity: Not sensitive to antibiotics
Which domain has the following characteristics:
- Type of cell: Eukaryotic
- Cell wall characteristics: May or may not have cell wall
- Antibiotic sensitivity: Not sensitive to antibiotics
Domain Eukarya
Which domains are antibiotic resistant?
Domain Archaea and Eukarya
Which domains have complex cell walls with peptidoglycan?
Domain Bacteria
Which domains consist of prokaryotic cells?
Domains Archaea and Bacteria
Which domain does not consist of prokaryotic cells?
Domain Eukarya
Which domain has complex cell walls with no peptidoglycan?
Domain Archaea
Which domains are sensitive to antibiotics?
Domain Bacteria
Which domains have organisms that may or may not have a cell wall?
Domain Eukarya
Which domains have chemically simple cell walls?
Domain Eukarya
What is fossilized evidence that supports evolution of microorganisms?
Fossilized stromatolites that are about 2 billion years old are rock formations with specific banding patterns caused by metabolic processes of some microorganisms.
Also, fossils of bacterial cells have been found that are about 3.5 billion years old.
Fossilized rock formations that are about 2 billion years old with specific banding patterns caused by metabolic processes of some microorganisms.
Stromatolites
Stromatolites
Fossilized rock formations with specific banding patterns caused by metabolic processes of some microorganisms.
Fossilized rock formations with specific banding patterns caused by metabolic processes of some microorganisms.
Stromatolites
How old are the fossilized stromatolites and fossilized bacterial cells that have been found that support evolution of microorganisms?
Stromatolites - 2 billion
Fossilized bacterial cells - 3.5 billion
Stromatolites and fossilized bacterial cells are evidence of what?
The fossilized evolution of microorganisms
What is the molecular evidence of microorganism evolution?
Analysis of DNA sequences can be used to determine relationships. Organisms with more similar DNA sequences being more closely related. Also, ribosomal RNA genes are found in all organisms and can be used to show relationships.
What are two ways technology is used as evidence of microorganism evolution?
DNA sequencing and ribosomal RNA genes.
How do DNA sequencing and ribosomal RNA genes provide evidence of microorganism evolution?
The more similar the DNA sequences and ribosomal RNA genes are, the more closely related they are.
Similar DNA sequences and ribosomal RNA genes that are more closely related are an indication of what?
Microorganism evolution
What is the endosymbiotic theory?
The theory is that chloroplasts and mitochondria in eukaryotes were once free-living bacteria that were engulfed at some point by pre-eukaryote ancestors. Over time the bacteria lost features to resemble the organelles present in eukaryotic cells today.
The theory is that chloroplasts and mitochondria in eukaryotes were once free-living bacteria that were engulfed at some point by pre-eukaryote ancestors. Over time the bacteria lost features to resemble the organelles present in eukaryotic cells today.
Endosymbiotic theory
In endosymbiotic theory, what two present-day eukaryotic organelles are thought to have once been free-living bacteria that were engulfed by pre-eukaryotic cells?
Mitochondria and chloroplasts
In the Phylogenetic Tree of Life, what are the three domains?
Domain Eukarya
Domain Archaea
Domain Bacteria
In the Phylogenetic Tree of Life, was there an original population of cells or cell-like things from which all life evolved?
Yes.
T/F
Over time, the bacterial cells that had been engulfed by the ancestors of the eukaryotic cells, lost features that made them recognizable as separate cells until they became mitochondria and chloroplasts we have today.
True
List four types of evidence of endosymbiosis
- Circular chromosomes: Mitochondria and chloroplasts have small, circular, bacteria-like chromosomes.
- Ribosome size: Mitochondria and chloroplasts have their own ribosomes, 70S like bacteria, not 80S like eukaryotes.
- Binary fission: Mitochondria and chloroplasts organelles divide independently of their parent cell through a process similar to binary fission.
- Multiple membranes: Mitochondria and chloroplasts organelles are surrounded by multiple membranes, which is indication of endocytosis.
What are these evidence of:
- Circular chromosomes
- Ribosome size closer to bacteria
- Reproduce by binary fission
- Multiple membranes
Endosymbiosis
What theory consists of ways that mitochondria and chloroplasts still resemble bacterial cells and are different than eukaryotic cells?
Endosymbiotic theory
What criteria is used to place organisms into or exclude them from taxonomic groups?
Groupings based on relationships, with organisms more closely related placed together while organisms more distantly related are placed in different groups.
Closeness of relationships is based on how recently organisms share a common ancestor is how what groups are composed?
Taxonomic groupings
Non-taxonomic groups are based on some feature other than what?
Relationship
Using taxons of Escherichia coli, arrange the taxonomic categories in a hierarchy.
DEAR Domain: Bacteria
KING Kingdom: None/Eubacteria
PHILIP Phylum: PROTEOBACTERIA
CAME Class: Gamma-proteobacteria
OVER Order: Enterobacteriales
FOR Family: Enterobacteriaceae
GOOD Genus: Escherichia
SOUP Species: coli
Name the taxons
DEAR Domain (most general)
KING Kingdom
PHILIP Phylum
CAME Class
OVER Order
FOR Family
GOOD Genus (Capitalized and italicized) Escherichia
SOUP Species: (Small letters and italicized) coli (most specific)
What is the correct grammar for the name of an organism using genus/species?
Genus: Capitalized and italicized first letter
Species: small letters and italicized
E. coli
What does O157:H7 indicate at the end of Escherichia coli O157:H7?
A strain of a species. A strain is a subset of a species indicated by letters and numbers. This strain of E. coli causes severe food poisoning when it enters the human digestive system.
What strain of E. coli causes severe food poisoning when it enters the human digestive system?
Escherichia coli O157:H7
What does E. coli O157:H7 cause?
Severe food poisoning in the human digestive system.
How to correctly format genus and species names of organisms?
- Genus* and species are always italicized.
- Genus* is always capitalized and may be abbreviated by first letter the second and subsequent times it is written in a document.
- Species* is never capitalized and is always written out.
- Escherichia coli*
- E. coli*
Describe characteristics of groups of eukaryotes:
- Fungi
- Protozoa
- Algae
- Helminthes
Fungi:
- Kingdom of eukarya (taxonomic group)
- Some organisms (yeasts) are unicellular; Others (molds, mushrooms) are multicellular
- Cell walls made of chitin, a carbohydrate polymer
- Filamentous grouth
- No photosynthesis
Protozoa (protists):
- Non-taxonomic group
- Single-celled eykaryotes
- Wide variety of different organisms
- Some photosynthetic, some not
Algae:
- Photosynthetic eukaryotes that lack characteristics to be classified as plants
- Unicellular or multicellular
- Many considered protozoa
Helminths:
- Non-taxonomic group of parasitic worms
- Multicellular eukaryotes
- Have microscopic larval stage which is tiny enough to be considered a microorganism and be included in microbiology
Of the different groups of eukaryotes, which ones are unicellular, multicellular or both?
Single: Protozoa (protists)
Multicellular: Helminths
Both: Fungi, algae
Of the different eukarotic groups, which ones are capable of photosynthesis?
Fungi - Not
Protozoa - Some
Algae - Are
Helminths - Not
What is the taxonomic group of fungi?
Kingdom (most general)
What group of eukaryotes cannot multiply in humans?
Helminths
This group of eukaryotes is also referred to as protists.
Protozoa
Name and briefly describe the three non-living infectious agents in microbiology.
- Virus
- Acellular infectious particles that consist of nucleic acid surrounded by a protein coat and sometimes an additional outer layer of lipids.
- Need to infect a cellular host and use its machinery in order to reproduce
- Cause HIV, influenza, Covid -19
- Prions
- Infectious proteins that can be transferred from one organism to another.
- Cause Crutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy (mad cow disease) and scrapie in animals
- Viroid
- Infectious molecules of RNA
- Do not encode proteins
- Generally cause disease only in plants
What type of non-living infectious microorganisms consist of nucleic acid surrounded by protein coat and sometimes a lipid layer?
Viruses
What is a virus?
A non-living infectious microorganism that consists of a nucleic acid (RNA or DNA) surrounded by a protein coat and sometimes a lipid layer.
What type of non-living infectious agent causes AIDS, influenza and COVID-19?
Viruses
What type of non-living infectious agent needs to infect a cellular host and use its machinery to reproduce?
Viruses
What type of non-living infectious agent can be transferred from one organism to another?
Prions
What type of non-living infectious agent causes Crueuzfeldt-Jakob disease?
Prions
What type of non-living infectious agent causes mad cow disease?
Prions
What’s another name for mad cow disease?
Bovine spongiform encephalopathy
What’s another name for bovine spongiform encephalopathy?
Mad cow disease
What type of non-living infectious agent causes scrapie in animals?
Prions
What type of non-living infectious agent only causes disease in plants?
Viroids
What type of non-living infectious agents are molecules of RNA?
Viroids
What type of information would you find in Bergey’s Manual of Systematic Bacteriology
Information for determining the identity of a bacterial species thorugh structural and functional attributes to arrange them into taxonomic groups.
What type of information is in the companion volume to Bergey’s Manual of Systematic Bacteriology?
Identification schemes to identify microorganisms aka determinative procedures.
It allows the use of structural and functional attributes of bacteria to arrange them into specific taxonomic groups.
Bergey’s Manual of Systematic Bacteriology
What is the main resource for determining the identity of bacterial species?
Bergey’s Manual of Systematic Bacteriology
What is Bergey’s Manual of Systematic Bacteriology?
The main resource for determining the identify of bacterial species.
What taxonomic group does Bergey’s Manual of Systematic Bacteriology identify?
Species of bacteria
What are the monomers, components and functions of carbohydrates?
- Polymer: polysaccharide
- Monomer: monosaccharides
- Function: Storage of chemical energy; structure of cell wall
What are the monomers, components and functions of lipids?
Simple lipid: No polymers
- 1 glycerol
- 3 fatty acids
- Storage of chemical energy
Complex lipid: No polymer
- 1 glycerol
- 2 fatty acids
- 1 functional group (e.g. Phosphate)
- Structure of cell membrane (amphipathic - having both hydrophobic and hydrophilic parts)
What type of lipid is composed of a phosphate group and 3 fatty acids and what does it do?
A simple lipid; stores chemical energy
What type of lipid is composed of a glycerol, 2 fatty acids and a functional group e.g. a phosphate group and what is it’s function?
Complex lipid: cell membranes
Why is a complex lipid that forms the cell membrane called amphipathic?
It has both hydrophilic and hydrophobic properties.
What is a structure called that has both hydrophilic and hydrophobic properties?
Amphipathic
What macromolecule is made of monosaccharides that form a polysaccharide chain?
Carbohydrates
What macromolecule has no polymer form?
Lipids
What macromolecule provides storage of chemical energy and cell wall (not cell membrane) structure?
Carbohydrate
What two macromolecules store chemical energy?
Carbohydrates and lipids
What are the monomers, components and functions of proteins?
- Polymer: Polypeptide/protein
- Monomer: Amino acid
-
Components:
- Amino and carboxyl groups
- R-groups: 20 different ones with various chemical properties
- Function: Many including catalyze chemical reactions (enzymes), antibodies and membrane pores
What are the components of the macromolecule protein?
Amino acid, carboxyl group, 20 different R groups
What macromolecule catalyzes chemical reactions?
Proteins
What macromolecule comprised antibodies?
Proteins
What macromolecule is an antibody made of?
Protein
What macromolecule makes up a membrane pore?
Protein
What are three functions of proteins?
Enzymes, antibodies, membrane pores
What are the polymers, components and functions of nucleic acids?
- Polymer: DNA (Deoxyribonucleotide)
-
Monomers: Nucleotide
- Bases: Adenine, Thymine, Cytosine, Guanine
- Sugar: Deoxyribose
- Phosphate: 1 to 3
- Function: storage of genetic information
- Polymer: RNA (Ribonucleotide)
-
Monomers: Nucleotide
- Bases: Adenine, Uracil, Cytosine, Guanine
- Sugar: Ribose
- Phosphate: 1 to 3
- Function: Intermediary used to make protein from information in DNA
What are the four bases in DNA and RNA?
DNA: Adenine, Thymine, Cytosine, Guanine (ATCG)
RNA: Adenine, Uracil Cytosine, Guanine (AUCG)
What is the difference between the bases in DNA and RNA?
DNA is Thymine
RNA has Uracil
What are the names of DNA and RNA
Deoxyribonucleic acid
Ribonucleic acid
What nucleic acid uses deoxyribose as its sugar?
DNA
What nucleic acid uses ribose as its sugar?
RNA
What is the difference in function between DNA and RNA?
RNA encodes proteins from information in DNA.
DNA stores the genetic information.
What is the intermediary used to make protein from information in DNA?
RNA
What is the macromolecule that stores genetic information?
DNA
DNA and RNA are what type of macromolecules?
Nucleic acids
What are the macromolecules in the human body?
Carbohydrates
Lipids
Proteins
Nucleic acids
Carbohydrates, lipids, proteins and nucleic acids are what type of molecules?
Macromolecules
What are the components of a nucleotide?
A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base.
What are the monomers of DNA?
Nucleotides comprised of bases (A, T, C and G), deoxyribose and phosphate
What are the monomers of RNA?
Nucleotides comprised of bases (A, U, C and G), ribose and phosphate
What are the polymers and monomers for nucleic acids?
Polymers: DNA, RNA
Monomers: Nucleotides (made of sugar, bases, phosphate group)
Name the three main types of bacteria cell shapes.
- Coccus - spherical, round (plural cocci)
- Bacillus - rod-shaped (plural bacilli)
- Spirals - corkscrew or spiral-shaped
How is a coccus bacteria shaped?
Spherical, round
What is a spherical or round bacteria called?
Coccus
What is a rod-shaped bacteria called?
Bacillus
What shape is a bacillus bacteria?
Rod-shaped
What shape is a spiral bacteria?
Spiral, corkscrew
What’s another name for the shape of a spiral bacteria?
Corkscrew
What are the possible arrangements of coccus bacteria cells in a single plane?
- Diplococci - 2 coccus cells in one plane.
- Steptococci - long chain
What are the possible arrangements of coccus bacterial cells in two planes?
- Tetrads - groups of four in two planes
What are the possible arrangments of coccus bacterial cells in three planes?
- Sarcinae - Groups of eight in three planes
- Staphylococci - grapelike clusters or broad sheets
What are the possible arrangements of bacillus-shaped bacteria?
- Single
- Diplobacilli - joined pairs
- Streptobacilli - long chains
- Coccobacilli - oval-shaped bacilli that look similiar to cocci
What shape of bacteria are these arrangements indicative of?
- Single
- Diplobacilli
- Streptobacilli
- Coccobacilli
Bacillus (rod-shaped)
Strepto- is a prefix of what arrangement of bacteria?
In a chain:
- Streptococci (round - in a chain)
- Streptobacilli (rod-shaped - in a chain)
Staphylo- is the prefix for what arrangement of bacteria?
Grapelike structures or broad sheets as in staphylococci.
What is a sarcinae arrangement of bacteria?
Groups of eight coccus-shaped bacteria in three planes
Tetrads and sarcinae arrangements are found in only what shape of bacteria?
Coccus (round)
Tetrads - groups of four in two planes
Sarcinae - groups of eight in three planes
Chains of bacteria are called what and in what shapes of bacteria do they exist?
Streptococci, spherical
Streptobacilli, rod-shaped
What is an oval-shaped bacteria that resembles a cocci?
Coccobacilli
What is a coccobacilli?
Oval-shaped bacteria that is similar to cocci
What are the arrangements of spiral-shaped bacteria and what are the terms?
- Vibrio are bent rod-shaped cells that don’t form a complete spiral.
- Spirillum are helical (full spirals) with rigid bodies.
- Spirochetes are helical (full spirals) with flexible bodies.
What’s the difference between spirilla and spirochetes?
Spirilla are helical-shaped bacteria with rigid bodies
Spirochetes are helical-shaped bacteria with flexible bodies
Which shape of spiral bacteria have rigid bodies?
Spirilla
(Spirochetes are flexible bodies)
Does this type of bacteria have a rigid or flexible body?
Spirochete
Flexible
(Spirilla have rigid bodies)
Does this type of bacteria have a rigid or spiral body?
Spirilla
Rigid
Spirochetes have flexible bodies
Bacilli bacteria come on what arrangements?
Single, diplobacilli, streptobacilli, coccobacilli
(single, two, chain, oval-shaped)
What shape of bacteria come in single, diplo- strepto- and cocco- arrangements?
Bacillus
(single, two, chain, oval-shaped)
What shape of bacteria appear in diplo-, strepto-, tetrads, sarcinae and staphylo- arrangements?
Coccus
- Diplococci - pair in one plane
- Streptococci - chain
- Tetrads - four in two planes
- Sarcinae - eight in three planes
- Staphylococci - grapelike clusters or broad sheets
Describe the composition and function of the glycocalyx and the difference between a capsule and a slime layer.
The glycocalyx is a substance secreted by cells that is external to the cell wall. The components and structure of the glycocalyx can vary greatly between species and can include polysaccharides, polypeptides, or other molecules.
A glycocalyx generally serves a protective function. They often protect the bacterial cell from host defenses (phagocytes and antibodies) to allow the bacterial cell to more easily infect a host (increases virulence), they can allow bacterial cells to stick together to form a protective structure called a slime layer, and can help prevent dehydration of the cell.
There are two classes of glycocalyx, capsules and slime layers. A capsule is a glycocalyx that is organized and firmly attached to the cell wall. A slime layer is a glycocalyx that is disorganized and loosely attached to the cell wall.
What is a glycocalyx?
A substance secreted by the cell wall that is external to the cell wall.
Is a glycocalyx internal or external to the cell wall?
External
Is a glycocalyx always one structure with one purpose?
No, a glycocalyx structure and components can vary greatly to include polysaccharides, polypeptides or other molecules.
What structure of a bacteria are external to the cell wall and may be formed from polysaccharides, polypeptides or other molecules?
Glycocalyx
What type of molecules can form the glycocalyx?
Polysaccharides, polypeptides and other molecules.
What function does a glycocalyx serve?
Protective - it protects the bacteria cell from host defenses
What type of bacterial cell structure that is external to the cell wall helps to protect the cell from host defenses?
Glycocalyx
How does the glycocalyx help to protect the bacteria cell from host defenses?
- Increase the cell virulence by allowing the bacterial cell to avoid host defenses to more easily move in the infected host
- Allow bacterial cells to stick together to form a protective structure called a slime layer
- Prevent dehydration of the cell
What bacterial cell structure increases the cell virulence, allows bacterial cells to stick together to form a protective layer and prevents dehydration of the cell?
Glycocalyx.
The type of glycocalyx called the slime layer helps bacterial cells stick together and prevents dehydration. It is disorganized and loosely attanced to the cell wall.
The other type of glycocalyx is the capsule which is organized and firmly attached to the cell.
What are two classes of glycocalyx?
- Slime layer helps bacterial cells stick together and prevents dehydration. It is disorganized and loosely attanched to the cell wall.
- Capsule which is organized and firmly attached to the cell.
What is the difference between a slime layer and a capsule?
What do they have in common?
- The slime layer is disorganized and loosely attached to the cell wall.
- The capsule is organized and firmly attached to the cell wall.
They are both classes of glycocalyx.
What do a slime layer and a capsule have in common?
They are both classes of glycocalyx.
What does it mean for a bacterial cell structure to increase virulence?
Protects the bacterial cell from the host’s defenses.
What is the term for a bacterial cell structure that helps protect the cell from the host’s defenses?
Virulence
Which type of bacterial cell structure can protect the cell from dehydration?
Slime layer
What bacterial cell structure is a class of glycocalyx, external to the cell wall, organized and firmly attached to the cell wall?
Capsule
It’s important for a bacterium to have the ability to cause disease by hindering the attachment of immune-system components. What is this called?
Virulence
What is virulence?
The ability of bacteria to cause disease by hindering the attachment of immune-system components.
What characteristics do fimbriae and pili have in common?
- They are rigid structures
- They project from the bacterial cells
- Hair-like in appearance
- Shorter, straighter and thinner than flagella
Given the following characteristics, which two cell structures do these refer to?
- Rigid
- Project from the bacterial cells
- Hair-like in appearance
- Shorter, straighter and thinner than flagella
Fimbriae (singular fimbria) and pili
Name three differences between fimbriae and pili.
- Fimbriae can number from a few to several hundred whereby pili are less numerous
- Fimbriae are shorter, pili are longer
- Fimbriae allow cells to adhere to each other or another surface, pili are used for DNA transfer (conjugation) and in some forms of motility.
What is the form of DNA transfer performed by the pili?
Conjugation
What are two functions of pili?
Some motility and transfer of genetic material (DNA) through conjugation
What cell structure performs these two tasks?
Motility
Conjugation
Pili
What cell structure helps bacterial cells to stick to each other and to other surfaces?
Fimbriae
What are the three parts of a flagellum?
From external to internal, the filament, the hook and the basal body.
What is the difference between a flagella in a gram+ and gram- cell?
Flagella in a gram- have two basal bodies, each embedded in one of the two layers of plasma membranes.
Flagella in a gram+ cells have one basal body embedded in the plasma membrane.
What is the function of the basal body on a flagellum?
Anchors the flagella to the cell membrane/cell wall and acts like a motor, spinning the remainder of the flagella
What part of a bacterial cell structure anchors the flagellum to the cell wall/cell membrane and acts like a motor to spin the remainder of the flagellum.
Basal body
What does the hook on a flagellum do?
The hook attaches the filament to the basal body.
What is the longest section of the flagella in prokaryotes?
The filament. It is thinner and more flexible than the hook.
At what structure in the prokaryotic flagellum does it spin?
The basal body which in turn rotates the hook and the filament to generate movement.
What is the difference between prokaryotic and eukaryotic flagella?
- Prokaryotic
- Made of a basal body, a hook and a filament
- Made of a globular protein called flagellin arranged in a hollow cylinder
- Spin from the basal body (the base)
- Use runs and tumbles to move
- Eukaryotic
- Made of microtubules in a 9+2 array, connected by motor proteins and crosslinker proteins
- Motor proteins cause microtubles to slide against each other, generating movement through the entire flagella.
- Move in a wave-like or whip-like manner.
In what domain do the flagella have cross-linker proteins?
Eukaryotes
In what domain are flagella made of microtubules in a 9+2 array?
Eukaryotes
In what domain are flagella made of a globular protein called flagellin arranged in a hollow cylinder?
Prokaryotes
In what domain do flagella move the organism in a whip-like and wave-like fashion?
Eukaryotes
In what domain do flagella move the organism through runs and tumbles?
Prokaryotes
What is the term for when an organism moves toward or away from stimulus?
Taxis
What is taxis?
When an organism moves toward or away from stimulus.
What is chemotaxis?
When an organism moves away or toward something due to chemical stimulus.
When an organism moves away or toward something due to chemical stimulus.
Chemotaxis
What is phototaxis?
When an organism moves away or toward something due to light stimulus.
When an organism moves away or toward something due to light stimulus.
Phototaxis
Describe the six terms of bacterial flagella arrangement.
- Atrichous
- Monotrichous
- Amphitrichous
- Lophotrichous
- Peritrichous
- Polar
- Atrichous - no flagella
- Monotrichous - a single flagellum
- Amphitrichous - flagella at both poles
- Lophotrichous - a tuft of flagella
- Peritrichous - flagella distributed over the entire cell
- Polar - at one or both ends of the cell
What do these terms refer to?
- Atrichous
- Monotrichous
- Amphitrichous
- Lophotrichous
- Peritrichous
- Polar
Flagella arrangements on bacterial cells
What is a monotrichous polar flagellum?
One flagella at one end of the cell
What does it mean for flagella to be amphitrichous?
Flagella at both poles of the cell
What are the terms for flagella at the poles?
Amphitrichous (at both poles) or polar (at one or both poles)
What does lophotrichous mean
Tuft of flagella
What is a tuft of flagella called?
Lophotrichous
What is the difference between lophotrichous and peritrichous flagella?
- Lophotrichous - a tuft
- Peritrichous - distributed over the entire surface
What’s the difference between monotrichous and amphitrichous flagella?
Monotrichous - one flagella
Amphitrichous - flagella at both poles
What does it mean for flagella to be polar?
At one or both poles of the cell
Compare the shape of bacterial and eukryotic chromosomes.
- Bacterial:
- Circular
- One chromosome
- One copy
- Eukaryotes
- Linear
- Multiple chromosomes
- Two copies (due to sexual reproduction)
Which organisms have chromosomes that meet these characteristics:
- Circular
- One chromosome
- One copy
Bacteria
Bacterial chromosomes differ from eukaryotic chromosomes in what ways?
- Bacterial:
- Circular
- One chromosome
- One copy
- Eukaryotes
- Linear
- Multiple chromosomes
- Two copies (due to sexual reproduction)
What type of organism has chromosomes with these characteristics?
- Linear
- Multiple chromosomes
- Two copies (due to sexual reproduction)
Eukaryotes
What is the typical number of chromosomes in prokaryotes?
One chromosome
Having one chromosome represents which type of organism?
Bacteria
What is the typical number of chromosomes in eukaryotes?
46
46 is the typical number of what in eukaryotes?
Chromosomes
How many copies of chromosomes exist in prokaryotic organisms?
One
How many copies of chromosomes exist in eukaryotic organisms?
2
Two represents the number of copies of what in a eukaryotic organism, a result of sexual reproduction?
Copies of chromosomes
What is the typical gram+ cell wall composed of?
Gram positive cell wall:
- Many layers of peptidoglycans stacked on top of each other to form a thick peptidoglycan layer. Made of NAMs with tetrapeptide sidechains attached to other NAMs by peptide crossbridges. Off the back end of the NAM is the NAG.
- Teichoic acid - either linked to lipids that are anchored in the membrane or directly attached to the peptidoglycan.
- Lipoteichoic acid - attached to membrane (go all the way through the peptodiglycans to the membrane)
- Interior to the peptodiglycan layer is a single cell membrane.
What is the typical gram negative cell wall composed of?
Gram negative cell wall:
- Single or partial layer of peptidoglycans within the periplasmic space which is filled by a visous liquid called the periplasm. Just like gram positive cells, peptidoglycan layer is made of NAMs with tetrapeptide sidechains attached to other NAMs by peptide crossbridges. Off the back end of the NAM is the NAG.
- Has two cell membranes: one external to periplasmic space called the outer membrane and one internal called the plasma membrane.
- Porins - protein channels that allow things into the periplasmic space.
- Lipopolysaccharides (LPS) - released when the cell dies and acts as an endotoxin in the human body. This has only been found in the walls of gram-negative bacteria.
- Teichoic acid and lipoteichoic acid have only been found in the cell walls of gram+ bacteria.
Do gram + or gram- have a periplasmic space?
Gram negative
Two membranes: an outer and a plasma membrane, are indicative of what type of bacteria?
Gram negative
Lipopolysaccharide in the outer membrane of a gram negative bacteria serves what purpose?
Released when the cell dies and the membrane breaks down and act as endotoxins in the human body.
This cell structure embedded into the outer membrane of a gram negative bacteria releases endotoxins into the host body when the cell dies.
Lipopolysaccharide
What are porins?
Protein channels in the outer membrane of a gram negative and gram+ cell wall that allow things into the periplasmic space. In gram+ cells that lack an outer membrane, the porins are attached to specific lipids in the cell wall.
What are the protein channels in a gram negative cell wall that allow things into the periplasmic space?
Porins
In the peptidoglycan layer in a bacterial wall, what are the two main amino acid sugars?
NAMs and NAGs
What are NAMs and NAGs?
Amino acid sugars in the peptodiglycan layer of a bacterial cell wall.
To what molecule is the tetrapeptide sidechain attached?
NAMs
To what are the peptide crossbridges attached?
The tetrapeptide sidechains
What do the peptide crossbridges in a peptidoglycan layer connect?
Peptide crossbridges connect directly to the tetrapeptide sidechains to connect NAMs
List four steps of Gram staining?
- Stain with crystal violet
- Treat with Gram’s iodine (mordant)
- Wash with alcohol (ethanol)
- Stain with safrinin (counterstain)
In the four steps of Gram staining, what are the outcomes?
- Stain with crystal violet (positively charged dark purple stain)
- Both gram+ and gram- cells appear purple.
- Treat with Gram’s iodine (mordant - negatively charged and will interact with crystal violet to form clumps)
- Both gram+ and gram- cells appear dark purple.
- Wash with alcohol (ethanol) - dehydrates cell and attempts to wash crystal violet from cell
- Cells of gram+ still appear purple because thick peptodoglycan layer prevents the iodine/crystal clups from washing out
- Gram-negative appear clear because alcohol washes away the crystal violet.
- Stain with safrinin (counterstain) - will cause clear cells to appear pink/reddish purple.
- Gram+ cells are already purple so the safranin taken up by the cells will not be seen. Still dark purple.
- Gram-negative cells which are colorless will take up the safranin and appear pinkish to reddish purple.
What is crystal violet?
A positively-charged stain used in the first step of Gram staining. Both gram+ and gram- cells will appear purple after application.
What is the first step in Gram staining and what is the result?
Crystal violet; both gram+ and gram-negative cells appear purple.
In what step of Gram staining do both gram+ and gram- cells turn purple for the first time?
Crystal violet, the first step
In what step of Gram staining is Gram’s iodine added and what is the purpose?
Second step; the negatively-charged iodine will react with the positively-charged crystal violet to form clumps that will not wash out of the gram-positive cells after washing with alcohol.
In Gram staining, why wash with alcohol?
To attempt to wash out the iodine/crystal violet clumps to see when cells are gram+ (remain purple) and which gram-negative (will be colorless).
What is a counterstain?
A stain with color contrasting to the principal stain.
In Gram staining, what is the counterstain and what color is it?
Safranin; reddish
Why do gram-negative bacteria turn colorless after the alcohol wash in Gram staining?
Gram negative bacteria turn colorless because they lack the thick peptidoglycan layers that hold the iodine/crystal clumps in place during an alcohol wash.
After which two steps in Gram staining do both types of cells appear purple?
First (adding crystal violet) and second (adding Gram’s iodine)
What structural difference between gram+ and gram-negative cells is responsible for the results of the Gram stain?
The thickness of the peptidoglycan layer is the cellular structure that is ultimately responsible for the difference in color at the end of the Gram staining procedure.
The crystal violet/iodine clumps that form in the thick, peptodoglycan layer of the gram+ bacteria don’t wash out with the alcohol rinse because it dehydrates the cell and the clumps get stuck along with the crystal violet.
In gram-negative cells, the alcohol wash also disrupts the double membranes and the thin peptidoglycan layer allowing the crystal violet to wash out.
What does the alcohol step do in Gram staining?
Dehydrates the cell, whereby the crystal violet gets stuck in the thick peptidoglycan laters of the gram+ cell wall.
Disrupts the membranes of the gram-negative cell wall resulting in the crystal violet clumps being washed out.
What two genus of bacteria does acid-fast staining help identify?
Bacteria of the genus Mycobacterium and pathogenic species of Nocardia that have acid-fast positive walls. These bacteria have mycolic acid in their gram+ cell walls which is hydrophobic and prevents uptake of most dyes, including Gram stain. They will appear colorless after Gram stain.
What color are acid-fast positive cells after Gram staining?
Colorless, clear
Which type of cells appear colorless after Gram staining?
Acid-fast positive
What is the material in the peptidoglycan layer in acid-fast positive cells that resists staining and why?
Mycolic acid; it’s hydrophobic
Which two genus of bacteria are acid-fast positive?
Mycobacterium and Nocardia
The genus of Mycobacterium and Nocardia represent what type of gram+ bacteria?
Acid-fast positive
Why does mycolic acid prevent gram+ bacteria from staining during Gram staining?
It’s hydrophobic and prevents the uptake of most dyes.
Steps to acid-fast staining.
- Stain with carbolfuchsin.
- Wash with acid-alcohol
- Counterstain with methylene blue
What is the result of each step of acid-fast staining?
- Stain with carbolfuchsin
- Stains both acid-fast positive and acid-fast negative cells pink
- Wash with acid-alcohol
- Acid-fast positive cells retain pink carbolfuchsin while it washes out of acid-fast negative cell walls resulting in them appearing clear.
- Counterstain with methylene blue
- Acid-fast positive cells will not take up methylene blue so remain pink. Acid-fast negative cells will take up the methylene blue and will appear blue.
At the end, acid-fast+ cells appear pink while acid-fast negative cells (both gram+ and gram-) will appear blue.
At the completion of both Gram staining and acid-fast staining, what color are each type of bacteria?
-
Gram staining:
- Gram+ appear purple (from crystal violet)
- Gram-negative appear pink (from safranin)
-
Acid-fast staining:
- Acid-fast positive appear pink (from carbolfuchsin)
- Acid-fast negative appear blue (from methylene blue)
In what stain do gram+ bacteria turn purple and gram-negative bacteria turn pink?
Gram staining
In what staining procedure do the two types of cells turn pink and blue?
Acid-fast staining
What are the functions of the bacterial cell wall?
Provide structure and to protect the cell.
What part of the bacterial cell wall adds rigidity?
The peptidoglycan layer is rigid which helps the cell maintain its shape, prevents the cell from rupturing and acts as an anchor for flagella.
What functions does the peptidoglycan layer serve in a bacterial cell wall?
The peptidoglycan layer is rigid so it helps:
- Maintains cell shape (rigidity)
- Prevents the cell from rupturing
- Acts as an anchor for flagella.
How gram-negative cell wall protect the cell?
Gram-negative cell walls have an outer membrane that is hydrophobic.
How do acid-fast positive cell membranes protect the cell?
Has thick peptidoglycan layer filled with mycolic acid that is hydrophobic that acts as a barrier to chemical entry (e.g. antibiotics).
Ziehl–Neelsen is what type of staining method?
Acid-fast staining
What’s another name for acid-fast staining method?
Ziehl–Neelsen
What is the structure of the bacterial membrane (plasma membrane)?
Phospholipids are arranged in two layers:
- Hydrophilic head groups facing outward
- Hydrophobic tail facing the center of the membrane
Integral proteins enter the hydrophobic region (center) and either transverse the membrane or go halfway in.
Peripheral membrane proteins either associate with phospholipid head groups or integral membrane proteins but do not enter the hydrophobic region of the membrane.
Which type of plasma membrane proteins do not enter the hydrophobic region of the membrane?
Peripheral proteins
Do peripheral or integral membrane proteins extend completely through the phospholipid bilayer?
Integral proteins
What is the difference between bacterial and eukaryotic ribosomes?
- Bacterial
- Smaller 30S + 50S subunits for a 70S ribosome
- Include 3 separate rRNA molecules
- Eukaryotes
- Larger 40S + 60S for an 80S ribosome
- Include 4 separate rRNA molecules
The ribosomes from what domain have 30S + 50S subunits for a 70S ribosome?
Bacteria
What domain has 40S + 60S subunits for an 80S ribosome?
Eukarya
What size ribosomes do bacteria have?
30S + 50S subunits for a 70S ribosome
What size are the ribosomes on eukaryotic cells?
40S + 60S subunits for an 80S ribosome
Are the surface shapes of bacteria and eukaryotic ribosomes similar or different?
Different
Why are bacteria ribosomes smaller than eukaryotic?
Because they have fewer proteins and smaller component RNA molecules than eukaryotic ribosomes.
Which domain has this characteristic: they have fewer proteins and smaller component RNA molecules than eukaryotic ribosomes.
Bacteria
Which group has larger ribosomes because they have more proteins and more component RNA molecules?
Eukaryotic cells
What is a plasmid?
Small, usually circular, double-stranded DNA molecules that exist outside the DNA of a cell but inside the cell.
What are small, usually circular, double-stranded DNA molecules that exist outside the bacterial DNA of a cell?
Plasmids
What is the function of plasmids?
Can be transferred from one bacterial cell to another, usually encode non-essential genetic information but can encode genes that could give bacterial cells that contain the plasmid an advantage in certain situations (e.g. genes that make cells resistant to antibiotics).
What structure of a bacterial cell does this: Usually encode non-essential genetic information but can encode genes that could give bacterial cells that contain the plasmid an advantage in certain situations.
Plasmids
What structure in a cell can encode for genes that might give a bacteria antibiotic resistance?
Plasmids
Antibiotic resistance, toxic metal tolerance, toxin production and the sythesis of enzymes are traits that can be encoded through what part of a bacterial cell’s structures?
Plasmids
Type of bacterial cell inclusion that is named because they sometimes stain red with certain blue dyes.
Metachromatic granules
Type of bacterial cell inclusion that is known as volutin and serves as a reserve of inorganic phosphate.
Metachromatic granules
Type of bacterial cell inclusion that is characteristic of Corynebacterium diphtheriae which causes diphtheria.
Metochromatic granules
Metachromatic granules are also known as what and serve as a reserve of what type of inorganic element?
Known as volutin
Reserve of inorganic phosphate
What type of bacterial inclusion causes Corynebacterium diphtheriae?
Metachromatic granules
What do the cellular inclusion called polysaccharide granules do?
- Consist of glycogen and starch
- Turn blue (starch) or reddish-brown (glycogen) in presence of iodine.
Which cellular inclusion consists of glycogen and starch?
Polysaccharide granules
In what cellular inclusion does starch turn blue and glycogen turn reddish-brown in the presense of iodine?
Polysaccharide granules
In what polysaccharide granules, what colors do starch and glycogen turn, respectively, in the presense of iodine?
- Starch - blue
- Glycogen - reddish brown
What cellular inclusion is revealed by staining cells with fat-soluble dyes like Sudan dyes?
Lipid inclusions
What is the only characteristic of Lipid inclusions that Dr. Suran listed on the Study Guide answer sheet?
Revealed by staining cells with fat-soluble stain like Sudan dyes.
What cellular inclusion is created by a build-up when the bacteria derive energy by oxidizing sulfur and sulfur-containing compounds?
Sulfur granules
Sulfur granules are what type of cellular structure that are caused by oxidizing sulfer and sulfur-containing compounds?
Cellular inclusion
What are carboxysomes?
A bacterial cellular inclusion that contains the enzyme ribulose 1, 5 diphosphate carboxylase and is required in photosynthesis for carbon fixation (is the rate-limiting step in photosynthesis).
What is the cellular inclusion that is required by photosythetic bacteria for carbon fixation (rate-limiting step in photosynthesis)?
Carboxysomes
What are the 3 structures on a lipopolysaccharide of a gram-negative bacterial cell?
- O polysaccharide
- Core polysaccharide
- Lipid A (endotoxin)
What are gas vacuoles?
A cellular inclusion that are hollow cavities consisting of individual gas vesicles covered in protein found in aquatic prokaryotes.
What are cellular inclusions that are hollow cavities consisting of individual gas vesicles covered in protein found in aquatic prokaryotes?
Gas vacuoles
Where do you find the prokaryotes that have a cellular inclusion called a gas vacuole?
Aquatic
What are magnetosomes?
Cellular inclusions of iron oxide formed by some gram-negtive bacteria that act like magnets that could serve to protect the cell against hydrogen peroxide accumulation by decomposing the hydrogen peroxide.
What are cellular inclusions with iron oxide called?
Magnetosomes
Which cellular inclusion might protect the cell from hydrogen peroxide accumulation by decomposing the hydrogen peroxide?
Magnetosomes
Which cellular inclusion behaves like a magnet?
Magnetosomes
Inclusions of iron oxide appear in which type of prokaryotic cells (gram+ or gram-negative)?
Gram-negative
Which cellular inclusions end in the following (there are 7 total):
- -somes
- -granules
- -vacuoles
- -inclusions
- -somes
- Carboxysomes - ribulose 1, 5-diphosphate carboxylase (photosynthesis)
- Magnetosomes - iron oxide to protect against hydrogen peroxide
- -granules
- Metachromatic granules - Volutin, stain red, inorganic phosphate, Corynebacterium diphtheriae
- Polysaccharide granules - glycogen (reddish in iodine) starch (blue in iodine)
- Sulfur granules - Buildup from oxidizing sulfur
- -vacuoles
- Gas vacuoles - hollow vesicle covered in protein in aquatic prokaryotes
- -inclusions
- Lipid inclusions - staining cells with fat soluble dyes like Sudan.
What are the four steps to the production of an endospore?
- A newly replicated bacterial chromosome and a small portion of cytoplasm are isolated by an ingrowth of the plasma membrane called the spore septum.
- The spore septum becomes a double-layered membrane that surrounds the chromosome, forming the forespore.
- Layers of peptidoglycan are laid down between the two membranes and a thick spore coat forms.
- The original cell is degraded and the spore is released if conditions exist.
What is an endospore?
The endospore is a tough structure of the cell that is metabolically inactive that allows the bacteria to survive in harsh environments. The endospore is then able to germinate and return to the vegetative (non-endospore) state when it encounters more favorable conditions.
What is a tough form of the cell that is metabolically inactive that allows the bacteria to survive in harsh environments.
Endospore
What structure is able to germinate and return the cell to the vegetative (non-endospore) state when it encounters more favorable conditions?
Endospore
Is an endospore formation a form of reproduction?
No, only one spore is formed per cell and the vegetative cell must rupture for the endospore to be released.
How are genera Chlamydia, Rickettsia and Mycoplasma different than typical bacterial cells?
Chlamydia and Rickettsia are intercellular parasites. They must:
- Live inside a host eukaryotic cell so rely on the host for many functions
- Lack many features found in free-living bacteria
- Can’t make their own ATP
Mycoplasma is are very small, possibly the smallest free-living cells (about 5% of a typical bacillus cell). The have:
- No cell wall so have varying shapes (pleomorphic)
- Stain pink with Gram’s stain but not Gram-negative
- When grown in culture, produce filaments that resemble fungi (which gave them their name)
Which two genera of bacteria are intercellular parasites that live inside a host eukaryotic cell so rely on the host for many functions.
Chlamydia and Rikettsia (genus are capitalized/italicized)
Which genera of parasitic bacteria lack many features found in free-living bacteria including making their own ATP which is why they rely on the host cells for these functions?
Chlamydia and Rikettsia
What are the characteristics of Mycoplasma?
- Very small, possibly the smallest free-living cells (about 5% of a typical bacillus cell).
- Have no cell wall so have varying shapes (pleomorphic)
- Stain pink with Gram’s stain but not Gram-negative
- When grown in culture, produce filaments that resemble fungi (which gave them their name)
Why do Mycoplasma stain pink with Gram’s stain even through they are gram-negative?
Mycoplasma have no cell walls.
What is the term for a bacteria that is able to assume different cell shapes (in some cases because it has no cell wall)?
Pleomorphic
What does pleomorphic mean?
Able to assume different cell shapes, like Mycoplasma.
Why must Chlamydia and Rickettsia live inside a host eukaryotic call?
Because they lack features found in free-living bacterial cells, including the ability to make their own ATP.
What diseases do members of the genus Chlamydia cause?
- Nongonococcal urethritis, the most common STD in the US
- Lymphogranuloma venereum, another STD
- Trachoma, which causes blindness in humans
- Psittacosis which causes a mild form of pneumonia.
What diseases do members of the genus Rickettsia cause?
- Typhus, transmitted by lice
- Endemic murine typhus, transmitted by rat fleas
- Rocky Mountain spotted fever, transmitted by ticks
What bacteria cause these diseases?
- Typhus, transmitted by lice
- Endemic murine typhus, transmitted by rat fleas
- Rocky Mountain spotted fever, transmitted by ticks
Rickettsia
What bacteria causes the following diseases?
- Nongonococcal urethritis, a common STD
- Lymphogranuloma venereum, another STD
- Trachoma, causes blindness
- Psittacosis, mild form of pneumonia
Chlamydia
What small (5% of a typical bacillus cell) bacteria causes the following diseases?
- Pneumonia
- Other respiratory diseases
Mycoplasma
Match the disease to the bacteria (not all diseases will be used):
Trachoma Mycoplasma
Endemic murine typhus Chlamydia
Nongonococcal urethritis Rickettsia
Trachoma - Chlamydia
Endemic murine typhus - Rickettsia
Nongonococcal urethritis - Chlamydia
Match the disease to the bacteria:
Respiratory diseases Mycoplasma
Rocky Mountain spotted fever Chlamydia
Lymphogranuloma venereum Rickettsia
Respiratory diseases - Mycoplasma
Rocky Mountain spotted fever - Rickettsia
Lymphogranuloma venereum - Chlamydia
Match the disease to the bacteria (not all diseases will be used):
Psittacosis Mycoplasma
Typhus Chlamydia
Lymphogranuloma venereum Rickettsia
Psittacosis - Chlamydia
Typhus - Rickettsia
Lymphogranuloma venereum - Chlamydia
Match the disease to the bacteria:
Psittacosis Mycoplasma
Typhus Chlamydia
Pneumonia Rickettsia
Psittacosis - Chlamydia
Typhus - Rickettsia
Pneumonia - Mycoplasma
When grown in culture, which bacteria can produce filaments that resemble fungi, which is how it got its name?
Mycoplasma
What bacteria causes different forms of typhus and is transmitted by lice, ticks or fleas?
Rickettsia
What bacteria causes trachoma, venereal disease and nongonococcal urethritis and psittacosis?
Chlamydia
What bacteria causes Rocky Mountain spotted fever and how is it spread?
Rickettsia, tick-bourne disease
What do the following describe and what do they mean:
Coccus
Bacillus
Spiral
The terms describe shapes of bacteria cells
Coccus - round, spherical
Bacillus - Rod-shaped
Spiral - helical, spiral
What do the following terms describe and what do they mean?
- Diplococci
- Streptococci
- Tetrads
- Sarcinae
- Staphylococci
They refer to arrangements of coccus bacteria:
- Diplococci - 2 cells in 1 plane
- Streptococci - a chain of cells in 1 plane
- Tetrads - 4 cells in 2 planes
- Sarcinae - 8 cells in 3 planes
- Staphylococci - grapelike clusters or broad sheets
What do the following terms describe and what do they mean?
- Single bacillus
- Diplobaccilli
- Streptobacilli
- Coccobacilli
They describe arrangements of rod-shaped bacterial cells.
- Single bacillus - obviously, 1 rod-shaped cell
- Diplobaccilli - joined pair
- Streptobacilli - long chains
- Coccobacilli - oval-shaped bacilli similar to cocci
What do the following terms refer to?
- Vibrios
- Spirilla
- Spirochetes
They refer to arrangements of spiral-shaped bacteria.
- Vibrios - curved rod-shaped bacteria
- Spirilla - helical bacteria with rigid body
- Spirochetes - helical bacteria with flexible body
Define the following term:
- Vibrios
Curved rod-shaped bacteria in the class of spirals
What do the following terms refer to and what do they mean:
- Atrichous
- Monotrichous
- Peritrichous
- Amphitrichous
- Lophotrichous
- Polar
Refer to bacterial flagella arrangement
- Atrichous - no flagellum
- Monotrichous - 1 flagellum
- Peritrichous - flagella distributed over the entire surface of the cell
- Amphitrichous - flagella at both poles
- Lophotrichous - a tuft of flagella
- Polar - flagella at one or both ends
Define the following term:
- Microtubules
The 9+2 arrangement that forms the flagella of eukaryotic organisms.
Define the following term:
- Conjugation
The process whereby a bacteria tranfers DNA from one cell to another through pili.
Define the following term:
- Virulence
The ability of a bacteria to easily infect a host.
What do teichoic acid and lipoteichoic acid refer to and what type of bacteria have them?
Teichoic and lipoteichoic acids are resident in gram+ bacteria to hold the layers of peptidoglycans together.
- Teichoic acid binds the peptidoglycan layers.
- Lipotechoic acid run all the way through the layers and binds the peptidoglycan layers to the plasma membrane
What are NAMs and NAGs and where are they found?
NAMS and NAGs are amino acid sugars that are the building blocks of the peptidoglycan layers of gram+ and gram-negative bacterial cell walls.
NAMs have the tetrapeptide sidechains attached and to those are attached the peptide crossbridges.
In what bacterial cell wall structure is Lipid A resident and what does it contain?
In a gram-negative cell, lipid A is the part of the lipopolysaccharide that contains the endotoxin that is released when the cell dies. It releases these toxins in the human host.
(I remember that this happens in a gram-negative cell because they don’t have the multiple peptidoglycan layers and/or mycolic acid to help protect them. )
What cell wall structure allows stuff into the periplasmic space through the outer membrane?
Protein channels called porins
What is a mordant?
A mordant is a substance used to set or stabilize stains or dyes.
What is a counterstain and what is the counterstain in Gram’s stain method and acid-fast staining?
A counterstain is a stain with color contrasting to the principal stain.
Gram’s stain: Safranin
Acid-fast staining: Methylene blue
For what are the following bacteria noteworthy?
- Myobacterium
- Nocardia
They have acid-fast positive cell walls
When listing sizes of ribosomes for prokaryotic and eukaryotic cells, remember odds and evens.
- Prokaryotic - odds - 30S + 50S = 70S
- Eukaryotic - evens - 40S + 60S = 80S
What cellular inclusion contains the enzyme ribulose 1, 5-diphosphate carboxylase and what is it used for?
Carboxysomes, carbon fixation for photosynthesis
The V’s to know for the test:
- Volutin
- Virulence
- Vibrios
- Viroids
- Volutin - The cellular inclusion called metachromatic granuoles that serves as a reserve for inorganic phosphate. These inclusions are characteristic of the bacteria, Corynebacterium diphtheriae, which causes diphtheria.
- Virulence - The ability of a bacteria to invade a host
- Vibrios - curved rods of the class of bacterial shapes called spirals
- Viroids - infectious molecules of RNA that only infect plants
Bacteria mentioned in the study question answers:
- Chlamydia
- Rickettsia
- Mycoplasma
- Mycobacterium
- Nocardia
- Rhizobium
- Thermus aquaticus
- Agrobacterium
- Bacillus thuringensis
- Penicillium chrysogenum
- Chlamydia - intercellular parasite responsible for STDs, trachoma and psittacosis
- Rickettsia - intercellular parasite responsible for typhus, Rocky Mountain spotted fever spread by fleas, ticks and lice
- Mycoplasma - tiny bacteria with no cell wall that is pleomorphic and will cause pneumonia and other respiratory diseases
- Mycobacterium - have acid-fast positive cell wall
- Nocardia - have acid-fast positive cell wall
- Rhizobium - complete nitrogen-fixing, a reaction that is only performed by microorganisms. These bacteria form a symbiotic relationship with legumes.
- Thermos aquaticus - A species that lives in hot springs and has thermostable DNA polymerase that is used for DNA sequencing to determine nucleotide sequence of a DNA molecule
- Agrobacterium - Genus of bacteria that injects DNA into plants. Used to introduce recombinant DNA to make transgenic organisms.
- Bacillus thuringensis - produces a BT protein that kills caterpillars
-
Penicillium chrysogenum - The fungi that contamination the plate of Alexander Fleming that led to the discovery of the first anitbiotic called penicillin.
*
People in microbiology history
- Anton von Leeuwenhoek
- Francesco Redi
- Louis Pasteur
- Ignatz Semmelweis
- Joseph Lister
- Edward Jenner
- Alexander Fleming
- Rosalind Franklin
- Francis Crick
- James Watson
- Anton von Leeuwenhoek - created over 400 microscopes as precursor to first light microscope, first to view microorganisms.
- Francesco Redi - Used “maggots on meat” to test the theory of spontaneous generation as opposed to biogenesis.
- Louis Pasteur - Used S-necked flasks to promote the work of Francesco Redi and further prove the theory of biogenesis and disprove spontaneous generation. Also, created process of pasteurization in resonse to brewers’ problem with spoilage.
- Ignatz Semmelweis - Physician at Obstetrics college that suggested the germ theory and aseptic technique.
- Joseph Lister - developed aseptic surgery based on Semmelweis’ work, sterilized surgical tools and surgical sites with carbolic acid (phenol).
- Edward Jenner - Developed vaccination for small pox by innoculating an unsuspectiing child and defined this protection as immunity.
- Alexander Fleming - Discovered penicillin, the first antibiotic by accident with plates contaminated with Penicillium chrysogenum.
- Rosalind Franklin - created x-ray chrystallography data that lead Crick and Watson to determine the structure of the DNA as the double helix.
- Francis Crick - used Rosalind Frankin’s x-ray chrystallography data to determine the structure of DNa as the double helix
- James Watson
What is the end color of acid-fast staining in:
- Gram+/acid-fast positive cells
- Gram+/acid-fast negative cells
- Gram negative cells (which are always acid-fast negative)
The end color of acid-fast staining is:
- Gram+/acid-fast positive cells will be pink
- Gram+/acid-fast negative cells will appear blue
- Gram negative (which are always acid-fast negative) cells will appear blue
As per Dr. Suran: “Cells with acid-fast positive cell walls have a Gram-positive-like cell wall, with a thick peptidoglycan layer, with the addition of a mycolic acid layer. If they are Gram stained, they will generally not give a positive Gram stain result, as the mycolic acid will prevent the cells from taking up either the crystal violet or the safranin (they will be clear or be poorly stained). They will be pink on an acid-fast stain. Some sources will count acid-fast cell walls as a different type of cell wall from the Gram-positive cell wall (primarily based on staining results), while other sources will include the acid-fast cell wall as a sub-type of the Gram-positive cell wall (primarily based on structure and close relationship to Gram-positive cells that lack mycolic acid).”
Steps in Gram staining vs. acid-fast staining.
Gram:
- Crystal voilet
- Gram’s iodine
- Alcohol wash
- Safranin
Acid-fast:
- Carbolfuchsin
- Alcohol wash
- Methylene blue
