exam 1 Flashcards
Contrast the diversity and population density of microbes compared to other organisms
Lowest: sharks Mammals Reptiles Birds Beetles Bacteria Highest: viruses Then: Lowest: Whooping cranes Humans Ants Bacteria Highest: Viruses Then: Largest: rigbee(dog) Cell phone Bee Flea Hair Human cell Bacteria Virus Atom
Recognize the role that microbes play in the biosphere
Play a vital role in anchoring the food web and bringing stability to the biosphere
Their absence would lead to disaster and collapse of the biosphere
Most species are benign therefore beneficial
Ex: yeast is important to food chain and tree burs help with nitrogen fixation
Can be good or bad
Cause influenza, zeka and norovirus
Important to ecosystem and food
Need microbes to survive
Review the impact that microorganisms have had on human health during the course of history
Black plague, also known as the bubonic plague. It was caused by the bacterium Yersinia Pestis, which killed a great number in Europe due to the occurrence of importing and exporting
Influenza caused many young healthy men to be infected
West Nile River Virus, which attacked the United States.
Zika which is the new buzz virus which came to the United States
Coronavirus and it being easily transmissable and deadly
Describe the function of components that make up the bacterial cell
Prokaryotes can be Gram Positive or Gram negative
Positive: They have a thick layer of peptidoglycan and only one plasma membrane, which help with substances going into and out of cells and has a purple color.
Negative: They have a thin layer of peptidoglycan, they have two plasma membranes. Top membrane which has LPS, which is an endotoxin and has a pinkish red color
Peptidoglycan are made up of NAM and NAG which are cross linking sugars.
Compare and contrast cell structure between bacteria and eukaryotes the bacterial cells based on their morphological features
Eukaroytes: Various organlles compartmentalization Dna in membrane Mitosis Dna with histones More than one chromosome Membrane bound organelles Large ribosome No cell wall Prokaryotes: Lack organization No compartments/organelles No dna in nucleus No mitosis No dna with histones One chromosome No membrane bound organelles Smaller ribosome Cell wall with peptidoglycan SAME: plasma membrane, ribosomes, nucleus, cytoplasm, DNA, chromosome
Diagram and label the cell wall and membrane(s) of both gram positive and gram
negative bacterial cells
gram positive= single cell wall, thick layer of peptidoglycan, teichoic does not touch membrane and leichoinic touches the membrane.
gram negative=double membrane with lps on outer membrane, single layer of peptidoglycan,
Describe how bacterial cells divide
Bacterial cells divide using binary fission (meiosis) – they divide autonomously
DNA replicates
Chromosome separate
Septum forms
Parent cell divides into two progeny (cytokenesis)
Logarithmic growth
Allow for dif cell arrangement via plane of segregation
Diagram and label a bacterial growth curve
- Replicate autonomously
- Lag phase upon initial entry into environement
- Log phase where this is exponential growth until environment becomes limiting
- Stationary phase
- Decline and cell death if conditions become unfavorable
Bacterial classificaiton
cocci=round bacilli=rod Shape and arrangement membrane/cell wall organizaiton G+ or g- Accessories Fimbriae-attach to surfaces Flagella-motility. Can be single, multiple, or peritrichous (all over surface) Capsule-has thick layer of polysaccharide adherence and evade immune system Sex pilus-allow for dna movement from receptor to recipient Growth conditions linked to metabolism Temp, ph, o2, nutrients
List various laboratory methods used to measure the growth of bacterial populations
Bacterial Culture which is plated on sample of media or the liquid broth and that is how they measure the oxygen levels
Aerobes: <3 Oxygen, they need it
Strict Anaerobes: Hate oxygen, can’t live with it
Facultative: Can and Can’t live, but prefer with
Microaerophiles: Only a little Oxygen (5%)
Areotolerant: Don’t care
Different Temperatures
Different pH
Internal Factors
Recall the basic concepts of glycolysis and respiration and how they provide energy for the cell
Glycolysis - the cell takes sugar and converts it into pyruvate - this yields 2ATP
Pyruvate can go two ways
Fermentation - gets rid of it (no oxygen)
Citric Acid Cycle - to make MORE energy
-pyruvate in high levels can be toxic
Classify bacteria based on the role of oxygen in their metabolism
Areboes: <3 Oxygen, they need it
Strict Anaerobes: Hate oxygen, can live with it
Facultative: Can and Can’t live, but prefer with
Microaerophiles: Only a little Oxygen (5%)
Areotolerant: Don’t care
Recognize the range and diversity of food sources available to bacterial populations
look at flashcard before
List various lab methods to characterize bacteria
- aspirated pus, swab, paper point
- clean sample
- smear (gram stain)
- culture (grow to purity in lab)
- agglutination test= pathogen must be in high enough concentration
- rapid identification still require isolation prior to characterization
Apply the concepts of the central dogma of molecular biology to bacterial cells
LIVING ORGANISMS ARE A COLLECTION OF GENES EVOLVING TO ENSURE SURVIVAL
- Replication → transcription → translation
- DNA → RNA → Proteins
- DNA starts replication with DNA synthesis, then continues onto RNA transcription with RNA polymerase, this then continues onto translation of the protein – which includes tRNA and ribosomes to make amino acids.
Contrast the structure of eukaryotic and prokaryotic genetic machinery including DNA structure and enzymes
Eukaryotic: DNA is organized and in the nucleus
-23 pairs of linear double stranded DNA chromosomes
-diploid
-3x10^9 bp
-25,000 proteins
Prokaryotic: The DNA is contained in nucleoid (non organized), circular chromosomes
-single,circular, double stranded DNA chromosome
-haploid
-5 million bp
-2000 proteins
-smaller scale than human cells
Phylogenetic Tree: Archaea, Eukaryotes, Bacteria
