Unit 1 Test Lecture's #1-#7 Flashcards
Define Microbiology
The study of microorganisms
What is a microbe?
A microorganism, especially one causing disease
What 6 types of microorganisms did we talk about in class?
Bacteria, algae, viruses, protozoa, fungi, helminths
Be able to identify the mode of nutrition (autotroph, heterotroph, saprotroph) and other general characteristics (body shapes, sizes, general structure, etc.) of each type.
Autotroph – Able to create it’s own food
Heterotroph – Food completely from its environment
Saprotroph – Get food from environment, but specifically dead matter (e.g. Fungi)
Define: Eukaryote and Prokaryote. Describe the main differences (e.g. do they both have DNA? If yes, is it the same structure? Is the DNA bound by a membrane? Are the cells different sizes? Do they have the same external features? Organelles?)
-They both have DNA.
-Prokayotic DNA is circular, while eukaryotic DNA is linear
-However, eukaryotes have their DNA in a membrane bound nucleus, prokaryotes are free floating
-Prokaryotes are single chromosome
-Eukaryotic cells are generally bigger
-Both cells have a cell membrane.
-Most prokaryotes have cell walls, while only some eukaryotes have cell walls
-Prokaryotes are unicellular, while eukaryotes are generally multicellular
-Prokaryotes lack nucleus, mitochondria, ER, Golgi body
Microbes have many functions. One of these functions is decomposition. Which microbes are responsible for decomposition and why is this function so important?
Bacteria and fungi are responsible for decomposition. This function is important as it allows the recycling of material. Without it, many of the Earth’s natural processes would come to a complete stop.
Microbes can also function as producers in ecosystems as well as symbionts. What is the importance of these roles and can you provide an example of each.
Producer – Both bacteria and algae produce much of the world’s oxygen
-Photosynthetic bacteria / eukaryotic algae
Symbiont – Fungi in symbiotic relationships w/ plants
-Gut flora
What other functions/roles do microbes play? (e. g. How did microbes such as cyanobacteria help shape the composition of the current atmosphere here on earth?)
Microbes contribute to:
Energy flow, food (nutrients in soil), biomass production, atmosphere alteration and symbiotic relationships
-Cyanobacteria are responsible for oxygenating the atmosphere and oceans
Which tool was essential is the first identification of microbes?
The microscope
What is the difference between sterile and aseptic?
Sterile means an environment where all microorganisms and their spores have been eliminated, while aseptic refers to the precautions taken to prevent microorganisms being reintroduced to an environment.
What is the germ theory of disease and which biologists are recognized as founding it?
The theory proposed that microorganisms can be the cause of disease
Koch and Pasteur are recognized as founding it
What is the name given to those microbes that are disease-causing agents?
What is a parasite?
What is a vector?
Over the years the major health risks have shifted from disease-causing agents [pathogenic microbes!!] (tuberculosis, pneumonia, diarrhea) to those that are NOT caused by microbes (heart disease etc.). Why? – How has the risk for infection been reduced?
Pathogens = Disease-causing microbes
Parasite – An organism that lives within or an another organism, benefitting from its expense
Vector – Something that can carry and potentially transfer a pathogen to another organism
General aspetic technique, public education regarding hygiene practices and information on microbe-germ theory
What are the human uses of microorganisms that we discussed in class? Define biotechnology and genetic engineering and provide examples of both.
Vaccines, food production (fermentation; bread, cheese wine), sewage treatment
Biotechnology - When microbes are manipulated to make products in an industrial setting.
- biodiesel from algae!
Genetic Engineering - Manipulates the genetics of microbes (plants, or animals) for desirable traits
- GMO Corn
Taxonomy: what are the three domains of life?
What are the five kingdoms?
What is phylogeny?
Why have archaea been separated from bacteria if they are both prokaryotes?
To which, bacteria or eukaryotes are the archaea most closely related? What is the classification scheme of organisms within a domain (i.e. kingdom, phylum . . . )? As you go from Kingdom to species, individuals get [MORE or LESS?] closely related?
Domains: Bacteria, archaea and eukaryotes
Kingdoms: Algae, Animals, Fungi, Plants, Protozoa
Phylogeny – study of evolutionary relationships between organisms
One of the main reasons archaea and bacteria are separate is due to bacteria having a peptidoglycan cell wall and archaea having a polysaccharide cell wall.
Archaea are more closely related to eukaryotes
Classification: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species
As you go from Kingdom to Species, individuals get more closely related
What is the correct way to write a name of an organism using its genus and species (what is capitalized? Is anything italicized?)? This system of using 2 names to identify an organism is called _______________________________.
Genus-Species
- Genus is capitalized
- Entire name is italicized
Binomial nomenclature
What are the three bacterial appendages?
What is the function of each?
Do all bacteria have all three?
What are the three parts of the flagella?
In general, how does it move (i.e. like a propeller or like a snake?)?
What is chemotaxis?
What are runs and tumbles?
How do they factor in to movement during chemotaxis?
What are the 4 types of flagella arrangement?
What is the benefit to those bacteria that form sex pili?
Flagella
-The Tail, used for movement
-Three parts: Filament, hook, basal body
-Like a propeller
Pilli
-For reproduction, transferring DNA
Fimbriae
-Used for attachment
Chemotaxis – The movement of an organism across chemical gradients
-Towards beneficial, away from harmful
-Runs move (generally straight) in one direction, tumbles allow them to stop and change directions
-The benefit is that it will increase genetic diversity, which helps over natural selection
What two features of bacterial cells are considered glycocalyx?
What is the function of each?
Glycocalyx
Slime layer: protects cell from drying out
Capsule: acts as protective shell
What are the four types of flagella arrangement?
Monotrichous: One flagella on a single pole
Lophotrichous: More than one flagella on two poles
Amphitrichous: One flagella on both poles
Peritrichous: Multiple flagella all over the bacteria
What are the functions of the bacterial cell membrane?
Selective permeability, Structural support, Nutrient acquisition (transport), energy reactions
Which two parts of bacteria constitute the cell envelope?
Do all cells have cell walls?
What are the major differences between a gram positive cell and a gram negative cell (e.g. which has more layers?
Which is more resistant to antibiotics and lysoszyme?
Which is more resistant to physical disruption?
Which has more peptidoglycan?, Which is more flexible?
Which has exotoxins?
The two parts are the cell wall and cell membrane
No, all prokaryotes but only some eukaryotes
Gram positive
-Protective, peptidoglycan cell wall
-30 Layers
-Rigid
-High Penicillin & lysozyme sensitivity
-Low physical disruption sensitivity
-Common Exotoxins
Gram negative
-Thin peptidoglycan cell wall
-Flexible
-Low penicillin& lysozyme sensitivity
-High physical disruption sensitivity
-Rare exotoxins
**What is the primary chemical make-up and function of the following: Cytoplasmic matrix, ribosomes, inclusions, nucleoid/chromosomes, actin cytoskeleton, and endospores.
How does plasmid DNA differ from the central round chromosome in the nucleoid region of bacteria?
Which of the two is necessary for bacteria to live?
Where does plasmid DNA come from and why is it beneficial?
Chromosomal DNA: Large, within nucleoid region, necessary for survival
Plasmid DNA: Small, independent, supplementary and not necessary for survival
Chromosomal DNA is necessary for bacteria to live, plasmid DNA is not.
Plasmid DNA can be obtained from other bacteria through Horizontal Gene Transfer, or taken from the surrounding environment as well.
It is beneficial as it can aid in antibiotic resistance and metabolic versatility.
***What is the opposite of sporulation (process by which bacteria form endospores)? What is a sporangium? How can endospore production cause health risks? What triggers endospore formation and what 2 things do the spores need to turn back into metabolically active (vegetative) cells? How to vegetative cells and endospores differ structurally?
The opposite of sporulation is germination
Sporangium – A structure where spores are produced and stored
Endospore production can cause health risks as they allow bacteria to remain in unfavorable conditions, and grow when favorable conditions have been met
Endospore formation is typically triggered by lack of nutrients or poor environmental conditions
Two things: Nutrients and temperature
Name and draw the three general shapes found in bacteria.
What arrangements do we find in bacteria?
What is the size range of bacteria? What does pleomorphism mean?
General shapes: Sphere-shaped (cocci), Rod-shaped (bacilli), spiral-shaped (spirochetes)
Arrangements: Diplo, tetrad, staphi, strepto, sarcina
Cocci (0.5 – 3.0 um)
Bacilli (0.2 – 2.0um wide x up to 20um long
Pleomorphism – the existence of variant forms in the same species or strain of microorganisms
Describe some of the methods used to classify microorganisms.
Provide examples of a phenotypic qualities used in bacterial classification schemes.
Why can it be hard classifying bacteria based on phenotypic qualities?
Some methods: Shape, arrangement, gram stain
In addition to the above: genetic and molecular info, biochemistry, GC content
It can be hard as phenotypic qualities are harder to see, whereas genetic/molecular info can be mapped out more explicitly
We discussed microbes with unusual qualities.
What were some of these unusual qualities?
How to these qualities allow these groups to thrive (i.e. how are they beneficial).
Which microorganisms are considered extremophile (extreme-loving) and live in places that are extremely hot, cold, salty, pressurized, etc?
Extremophiles, bacteria that may be able to live in areas of extremely high/low conditions (temperature, salt, pH)
For halophiles: allows them to survive high salt concentrations
Photosynthetic bacteria, can make their own food
Low competition.
Hot: Thermophiles
Cold: Psychrophiles
Salt: Halophiles
Acidic: Acidophiles
Pressurized: Barophile
Be able to identify which internal and external features are found only in prokaryotes and those found only in eukaryotes.
What are the differences in:
Cell size?
DNA structure?
DNA location?
Flagella composition and movement? Cell division?
Cell size
-Prokaryotes: 1-10 um
-Eukaryote: 10-100 um
DNA structure:
-Prokaryotes: circular, single chromosome, free floating
-Eukaryotes: Linear, multi-chromosome, membrane-bound nucleus
DNA location
-Prokaryotes: Nucleoid
-Eukaryotes: Nucleus
Flagella composition and movement:
-Prokaryote flagella: Lacks microtubules; like a motor with runs and tumbles
-Eukaryote flagella: Contains microtubules; like a whip with fluid like movement
Cell Division:
-Prokaryotes: Chromosomes pulled apart to inner membrane
-Eukaryotes: Chromosomes pulled apart to cytoskeletal components
What is taxonomy?
The branch of science regarding classification (of organisms)
What are three domains. Are Eukaryotes more related to Archaea or are bacteria? How can we tell?
Three domains: Bacteria, archaea and eukaryotes
Eukaryotes are more related to archaea as they have a more recent common ancestor, in contrast to prokaryotes.
Be able to identify the major differences among organisms in the 5 kingdoms.
(How are the groups separated?;
are organisms within each kingdom multicellular, single-celled, autotrophs, heterotrophs, both?;
what type of health effects can some organisms cause?,
mode of nutrition?
Overall structure?)
4 Kingdoms: Animals, fungi, protists, plants
Animals: Multicellular, heterotrophs
Fungi: Multicellular, heterotrophic
-Fungi causes Mycoses, yeast infection
Plants: Multicellular, Auto- and heterotrophic
Protozoa: Unicellular, heterotrophs
-Protozoa cause African sleeping sickness, Chagas
