Structure And Function Flashcards
Name the general cell shapes
Coccus- spheres in bunches, chains, quartets Rod - bacilli, alone, chain Vibrios- bent rods Spirillum Spirochete Budding and Filamentous
What domains have histones?
Archea and Eucarya
What is an Ori C and who has one?
It is the origin of replication on a circular chromosome. Bacteria and archeae both have circular genomes.
Name an actin homolog
Mre B
Name a tubulin homolog and its function
Fts Z. Causes septum in binary fission, contraction in cell replication
What are trichome s?
Long fillament cells that are connected intracellulaurly. Found in Cyanobacteria. Can differentiate into heterocysts.
What are heterocysts?
A specialized trichome of Cyanobacteria that a cell will differentiate into when N is needed. It produces the enzyme nitrogenase that can fix N. can not form in the presence of Oxygen
Name the major of features of Archaea lipid membranes
Ether bonds G1p Isoprenes in Archaea Bilayers or monolayers Cyclonpentene rings
Name the major features of Bacteria and Eucarya lipid membranes
Ester bonds
G3P
Fatty acids
Only bilayers
How do you identify a gram + cell?
Thick peptidoglycan wall outside of membrane
Has a very small periplasm between the membrane and peptidoglycan.
Staphylococcus.
Name the features of a gram - cell
Thin peptidoglycan wall located in the periplasm, between the inner and out membranes.
E. coli
What type of cells have a lipopolysacharide outer membrane covering their thin peptidoglycan layer?
Gram -
What type of cell has a thick peptidoglycan layer making up their cell wall?
Gram +
Gram positive organisms stain what color?
Blue/ purple
What color do gram negatives stain?
Pink/ red
What are gas vacuoles and who uses them.
Vesicles of trapped air used by Cyanobacteria to travel up and down in water
What is polhydroxybuterate, PHB?
A lipid like structure that can store extra C for lean times. Can make plastics and biofuels from.
What is volutin?
Pyro phosphate granules that are stored in cytoplasm.
What is a carboxysome?
Protein based polyhedral body that contains molecules for carbon fixation, are invaginations of the plasma membrane.
What are invaginations?
Invaginations of the plasma membrane are a way to sequester some processes, increases cell surface area
Ex. Thylakoid membrane in Cyanobacteria
What type of phospholipid bilayer do high temperature organisms have?
Saturated fatty acids, ester bonds
What are hopanoids?
Strengthen membrane, all bacteria have except mycoplasma s ( have sterols)
What are sterols and who has them!
Like cholesterol, used to strengthen lipid membranes, only in eukarya
What is the peptidoglycan cell wall of bacteria made of?
Made of two sugars, NAG and NAM
Are connected by beta 1,4 linkages with variable #’s and types of amino acids
Are in D conformation
Usually 3 strings of NAG/NAM connected with interbridge links to other strands
What is lysozyme?
An enzyme that cleaves the beta 1,4 linkages of nag/nam sugars in bacteria
What are beta lactane antibiotics and how do they work?
Penicillin and vancomycin. It targets the interbridge links of nag/nam. Easiest to kill gram + bacteria cause cell wall is exposed
What are the cell walls of archeae made of?
Pseudo peptidoglycan, aka psuedomurein
Nag and NAT
Beta 1,3 linkages
Lysozyme doesn’t work and most are not antibiotic sensitive but depends on cell wall and linkages
In chemotaxis, what spin direction is caused by attractants?
Counterclockwise rotation. Flagella bundle together and push cell forward, run.
In chemotaxis, repellents rotate which way?
Clockwise rotation, flagella fly apart, tumble- change direction
Under what conditions would lysozyme be effective in killing a bacteria when penicillin is not?
No growth
What is an S layer?
Surface crystalline layer, highly structured protein layer that may help with attachment or protection, in some archeae and bacteria
What is glycocalyx?
A diffuse, slime like layer, coating on outside of cell
What is a capsule?
A defined coating on outside of cell, protects pathogens from phagocytosis by host cells.
Mostly made of sugars, some amino acids and proteins
Is a virulence factor in pathogenic species with a capsule
What are fibriae?
Long hairlike structures on outside of some gram - species. 7 types. Are very fragile and can break off easily. 1,4 can regrow quickly
1: adhesion
4: twitching motility
7: sex pilus- conjugation, lateral gene transfer
