Chapter 2 Flashcards
What does cell morphology mean?
The cell shape
What is the smallest microbe cell?
.2 micrometers-Mycoplasma sp.
What is the largest microbe cell?
700 micrometers-Epulopiscium fishelsoni
List two characteristics about Eupulopiscium fishelsoni.
It has thousands of copies of genome. It has unusual cell division.
Why should cells be small?
Larger surface-to-volume ratio, which gives a faster rate of nutrient exchange, faster growth, high population densities, and faster rates of evolution.
How small is too small for a cell? Why is this too small?
.15 micrometers. This is too small because they need space for proteins, nucleic acids, ribosomes, etc. This can create streamlined genomes, which results in missing genes.
What helps with the rigidity of the cytoplasmic membrane in eukaryotes? In bacteria?
Sterols; hopanoids
How is the membrane made in bacteria?
Ester linkages bond fatty acids to glcyerol
How are archaeal membranes different than other membranes?
Ether linkages bond hydrophobic side chains (isoprene) to glycerol, instead of binding fatty acids. Isoprene is composed of 5 hydrocarbons
What area do integral membrane proteins span?
Across the whole membrane
List three functions of the cytomplasmic membrane.
- Permability barrier
- Protein anchor
- Energy conservation
How does the cytoplasmic membrane serve as a permeability barrier?
It prevents leakage and functions as a gateway for transport of nutrients into, and wastes out of, the cell
How does the cytoplasmic membrane serve as a protein anchor?
It serves as a site of many proteins that participate in transports, bioenergetics, chemotaxis
How does the cytoplasmic membrane serve as energy conservation?
It serves as a site of generation and use of the proton motive force
Simple transport
Driven by the energy in the proton motive force
Group translocation
Chemical modification of the transported substance driven by phosphoenolpyruvate
ABC transporter
Periplasmic binding proteins are involved and energy comes from ATP
What system runs group translocation?
The phosphotransferase system
What happens during the use of the phosphotransferase system?
The substrate is chemically modified as it passes through the membrane. Translocates groups like fructose, glucose, and mannose.
Describe ABC transport systems.
There are 200 systems of ATP-binding cassette proteins. This involves the uptake of sugars, amnio acids, sulfate, phosphate, and trace metals.
Which bacterial cell has an outer membrane?
Gram-negative
List 3 functions of cell walls.
They prevent osmotic lysing, they determine the shape, and they provide rigidity.
What is peptidoglycan?
A polysaccharide composed mainly of N-acetylglucosamine and N-acetylmuramic acid
What does the outer membrane contain?
Phospholipid, protein, and polysacchardides; AKA lipopolysaccharide layer (LPS)
