Exam #1 Study Guide

bacteria: peptidoglycan (NAG NAM); archaea: pseudomurein (NAG NAM); plants: cellulose modified form of beta glucose; fungi: chitin modified form of beta glucose

What is the difference between wall structures in prokaryotes and eukaryotes?

(bacteria, archaea, plants, fungi)

prokaryotes: circular long, one big piece; eukaryotes: linear

What is the difference between DNA organization in prokaryotes and eukaryotes?

prokaryotes: no membrane-bound organelles, no histones, 70S ribosomes; eukaryotes: membrane-bound organelles, histones, 80S ribosomes

What is the difference between organelles in prokaryotes and eukaryotes?

prokaryotes: binary fission; eukaryotes: mitosis and meiosis

What is the difference between division methods in prokaryotes and eukaryotes?

bacillus = rods; coccus = spherical; coccobacillus = thick sphere/rod; vibrio = curved rod; spirillum = thick, rigid spiral; spirochete = thin, spiral-like corkscrew; star-shaped; rectuangular-shaped; diplococci = pairs; staphylo = clusters; strepto = chains; tetrads = groups of 4; sarcinae = groups of 8

Describe the numerous shapes and arrangements possible for prokaryotes.

bacillus = B. cereus, all clostridium; coccus = streptococcus pneumonia; cocobacillus = E. coli; vibrio = vibrio cholerae; spirillum = spirillum minus; spirochete = treponema pallidum; star-shaped = Stella; rectuangular-shaped = haloarcula

What are some specific genus species of the numerous shapes and arrangements possible for prokaryotes?

sphyllis and leptospira interrogans which causes leptospirosis

waht does treponema pallidum cause?

ponds, soil, lake erie

where is stella found?

lakes, soil, halophile

where is haloarcula found, and what is it?

haloarcula

Provide the name of the one archaean that was discussed in lecture.

anything that can cause disease

What does virulence mean?

yes, because it aids to avoid the host’s immune system

Are capsules a virulence factor, and if so, why?

yes, because it is able to stick into the host’s body

Are slime layers a virulence factor, and if so, why?

capsules, slime layers

What are the 2 parts of glycocalyxes?

found outside bacterial wall, neatly organized, evades host immune system, hard type, mostly non-ionic

Know the functions of capsules.

streptococcus pneumonia, bacillus anthracis

What are 2 examples of prokaryotes with capsules?

unorganized and loose, used for attachment to things, fimbriae work with slime layer to form a biofilm

Know the functions of slime layers.

non-ionic, so nothing binds to it, serves as a cloak to evade the immune system

Give details of streptococcus pneumonia’s capsule.

made of d-glutamic acid, so it hides in plain site

Give details of bacillus anthracis’s capsule.

filament: outermost region, preforms movement; hook: attaches to filament; basal body: consists of rods and pairs of rings, anchors flagellum to the cell wall and plasma membrane

What are the 3 parts of the prokaryotic flagella (give description too)?

plasma membrane

Where do flagella anchor in gram-positive bacteria?

plasma membrane, cell wall

Where do flagella anchor in gram-negative bacteria?

rotate and are made of flagellin protein

Give details of prokaryotic flagella.

peritrichous, monotrichous, loptrichous, amphitricous

What are the 4 trichous arrangements of flagella?

flagella on all sides, salmonella

Describe peritrichous flagella and give an example.

singular flagella on one end, sperm

Describe monotrichous flagella and give an example.

many flagella but only on one end, vibrio

Describe lophotrichous flagella and give an example.

some flagella on each end, spirillum

Describe amphitrichous flagella and give an example.

run/tumble, chemoattractant, chemorepellent

What are 3 flagella movement methods?

flagella allows the bacteria to move to or away from the stimulus

What occurs in the run/tumble?

a chemical attracts bacterial movement

what occurs with chemoattractants?

a chemical repels bacterial movement

what occurs with chemorepellents?

endoflagella

What’s another name for axial filaments?

spirochetes (syphilis)

What is the only bacteria axial filaments are found?

at one end of the cell

Where are axial filaments found?

corkscrew movement

What type of movement do axial filaments preform?

rotation is the same in both

What is similar between flagella and axial filaments?

made of pilin

What is the composition of both pili and fimbrae?

little fingers; allow attachment; works with slime layers to make biofilms

Describe the function of fimbrae.

used for movement (twitch/glide); used for DNA transfer; takes place in conjugation

Describe the function of pili.

only between two living cells; HGT between an f+ cell and an f- cell, plasmids get sent between the tunnels in the cell

What is conjugation?

found that if you give a non-lethal strand of bacteria and a killed strand of lethal bacteria, something will still die because there is ability to transfer genes

Describe the Griffith transformation experiment.

conjugation, transformation, transduction

What are the 3 types of horizontal gene transfer?

bacterial phage infects a bacterial cell, any genes it has may get taken up by the virus; bacteria dies via microphage and transfer genes

Describe the events of transduction.

dead cell to living, plasmid gene transfer; cells die and a second cell takes up the plasmid that is in the environment

Describe the events of transformation.

the ability of a microbe to invade

What is pathogenicity?

prevents osmotic lysis, protects cell membrane

What are the functions of a bacterial cell wall?

made up of peptidoglycan (NAG/NAM disaccharide units); rows are created by polypeptides that link NAG/NAM; tetrapeptides bind NAM; cross-bridges link tetrapeptides; bricks = NAG/NAM; mortar = polypeptide rows

What are bacterial cell walls made of?

found in tears, sweat, saliva, and mucus; attacks glycosidic linkages (destroys brick layer), and then osmotic lysis kills cells; gram-positive are very sensitive to them

Describe lysozymes.

antibiotic, interferes with cross-bridge formation (prevents mortar) and then osmotic lysis will kill the cells

Describe penicillin.

thick peptidoglycan, have teichoic acids, antigen specificity

Describe gram-positive cell walls.

thin peptidoglycan, outer membrane space, periplasmic space (between outer membrane and plasma membrane)

Describe gram-negative cell walls.

have carboxyl group, are negative, Na/K pumps are attracted to them, regulate cation movement

Describe the overall function of teichoic acids in certain microbes.

teichoic acids + polysaccharides

_______ _______ + __________ provide antigen specificity

links cell wall to plasma membrane

Describe the function of lipoteichoic acids.

links to peptidoglycan

Describe the function of wall teichoic acids.

to protect from phagocytes, complement, and antibiotics

Describe the overall function of lipopolysaccharides in the course of pathogenesis in a human host.

O polysaccharide = antigen (ex. E. coli: O157:H7); lipid A = endotoxin; core polysaccharide = connects O poly to lipid A

What are the 3 parts of lipopolysaccharides and describe them? (Plus give examples if you can)

when an antibiotic kills bacteria, lipid A gets released and when the immune system recognizes it as an endotoxin, there can be an inflammatory response that kills the patient, so you must treat slowly

When is lipopolysaccharide toxic?

polysaccharides, lipoproteins, phospholipids

What is the outer membrane composition of lipopolysaccharides?

similar to gram-positive cell walls, but have a waxy lipid (mycolic acid) bound to the peptidoglycan; use carbolfuschin and methylene blue; ex. mycobacterium tuberculosis

Describe acid-fast cell walls, describe how it’s stained, and give an example.

grants the microbe resistance to acid-alcohol wash/rinse steps; without it acid-alcohol will strip away primary dye (carbolfuschin)

What does mycolic acid do, and what happens if it’s not used?

carbolfuschin: labels acid-fast cell walls; methylene blue: labels non-acid fast cell walls

How do carbolfuschin and methylene blue dyes work?

mycoplasmas: have sterols in membrane, ex. protoplast (wall-less gram-positive); spheroplast (wall-less gram-negative)

Describe wall-less microbes, and give an example.

either wall-less or walls of pseudomurein

Describe archaea cell wall.

fluid mosaic model: membrane is viscous, fluid = phospholipid bilayer, mosiac = proteins within bilayer

Understand the general features for prokaryotic plasma membrane kinetics.

(fluid mosiac model and lipid bilayer)

peripheral proteins: on membrane surface and are associated with either outer or inner leaflet; integral proteins: pass through at least one leaflet; transmembrane proteins: penetrate both leaflets

Describe the 3 types of proteins in the fluid mosiac model.

selectively permeable

________ ________ - small and uncharged can go through, large and charged can’t

alcohols, detergents, antibiotics

damage to membrane by ________, ________, and ________ can cause leakage of cell contents

chromatophore, site for concentration of photosynthetic pigments

What else is a prokaryotic thylakoid called, and what is it a site for?

rhodospirillum rubrium

What is the autotrophic microbe discussed in class that has chromatophores?

helps increase surface area for more transport and activity

What is the significance of folding the membrane inwards repeatedly?

movement from high to low; exs. group translocation, symporter, antiporter

Describe active transport and give examples.

substance is chemically altered as it crosses membrane; requires transporter protein and phosphoenolpyruvic (PEP) acid

what is group translocation, and what does it require??

high to low concentration; exs. osmosis, uniporter, simple diffusion

Describe passive transport and give examples.

group translocation, hexokinase, active transport

What is the one case of prokaryotic-only transport, what enzyme is involved in it, and is it active or passive?

enzyme that adds phosphate to 6’ carbon of glucose

What is hexokinase?

like eukaryotic microfilaments; these are types of proteins, in inner leaflet

Describe MreB and ParM proteins.

like eukaryotic intermediate filaments; these are associated with the nucleiod

Describe cresetin proteins.

like eukaryotic microtubules; work as the rail network

Describe FtsZ protein.

plasmids

________ - extrachromosomal genetic elements; carry non crucial genes

bacterial chromosomes

_______ ________ - circular thread of DNA that contains the cell’s genetic info

circular DNA with hundreds of base pairs

How is prokaryotic DNA organized?

the proton (h+) can rotate the protein as it moves in, which then causes the DNA to super helically twist

Why is prokaryotic DNA superficially twisted?

70S ribosomes, made up of 50S (large subunit) and 30S (small subunit)

Describe prokaryotic ribosomes.

80s ribosomes, made up of 60s (large subunit) and 40s (small subunit)

Describe eukaryotic ribosomes.

large subunit of 70S ribosomes, used for scaffolding and contains complex of 23S rRNA and proteins which has active site to build peptide bonds

Describe 50S ribosomes.

small subunit of 70S ribosomes, has complex of 16S rRNA and proteins, which allows binding to mRNA

Describe 30S ribosomes

rRNA

______ has catalytic sites to form peptide bonds during translation

large subunit of 80S ribosomes, contains complex of 28S rRNA and proteins

Describe 60S ribosomes.

small subunit of 80s ribosomes, has complex of 18s rRNA and proteins

Describe 40S ribosomes.

located in inner leaflet; translate proteins for secretion or insertion into plasma membrane

Describe membrane-bound ribosomes.

located in cytoplasm; translate cytosolic proteins like MreB and ParM, cresetin, and FtsZ

Describe free-floating ribosomes.

unique to prokaryotes, can tell what infection someone has

Describe inclusion bodies.

phosphate reserves; seen in corynebacterium diphtheriae which makes endotoxin which can kill kids and adults

Describe metachromatic granules (volutin), and what is it seen in.

energy reserves

Describe polysaccharide granules.

energy reserves

Describe lipid inclusion.

energy reserves

Describe sulfur granules.

RuBisCo enzyme for CO2 fixation during photosynthesis

Describe carboxysomes.

protein covered cylinders that maintain buoyancy; important for photosynthetic microbes; make microcystin toxins which dogs are succeptible to

Describe gas vacuoles.