Microbiology Exam 1- BIOL 400 - KU 2026

Spring 2026, Hotze, University of Kansas

/What type of cell wall is this?

Gram positive

What type of cell wall is this?

Gram negative

Label Structures A-E in this diagram of gram-positive cell wall

a. Periplasmic space

b. plasma membrane

c. peptidoglycan

d. lipoteichoic acid

e. teichoic acid

Label Structures A-H in this diagram of gram-negative cell wall

a. Braun’s lipoprotein

b. porin

c. LPS

d. outer membrane

e. periplasmic space

f. plasma membrane

g. peptidoglycan

h. integral protein

Woese

three domain system

Hooke

compound 30x

Leeuwenhoek

simple 275x

Pasteur

swan neck flask

Lister

aseptic techniques

Koch

postulates for disease-causing pathogen

Ehrlich

selective toxicity

Fleming

penicillin

Domagk

living system to test drugs

RNA Theory of Life - Why RNA? (2 functions)

catalytic and heriditary functions

Evidence for endosymbiotic theory

circular dna

double membrane

independent reproduction

unique ribosomes

Koch’s postulates (4 steps)

isolate in pure culture

infect new host

new host get sick

isolate from new host

Problems with Koch’s postulates (3 things)

pathogen may not cause symptoms

disease caused by multiple pathogen

some unable to be grown in pure culture

6 basic shapes of bacteria

1. cocci - circle

2. bacilli - rod

3. vibrio - curved rod

4. spirilla - rigid spiral

5. spirochete - loose spiral

6. pleiomorphic

Label bacteria shapes

a. monococcus

b. diplococcus

c. streptococcus

d. tetrad

e. staphylococcus

Two types of proteins in plasma membrane

1. integral

2. peripheral

what unique about amphipathic lipids

have both hydrophobic and philic region

what 2 things do all bacterial cells have for their outer layers

plasma membrane

cell wall

How is bilayer held together?

vanderwal bonds

Factors affecting membrane fluidity

temperature

Fatty acid tail length

fatty acid saturation

in hot environments, membranes become (more/less) fluid

more

in cold environments, membranes become (more/less) fluid

less

between environmental temperature and pH, which can bacteria influence and which can they not influence

can change pH,

cannot change temperature

Primary active transport is (uni/coupled) transport, (does/doesn’t) use ATP hydrolysis and uses (ABC transporter/ion gradient)

unitransport

ATP hydrolysis

ABC transporter

Secondary active transport

ion gradient

coupled transport

symport or antiport

Group translocation

chemically modifis molecule to prevent it from leaving

4 cell well functions in bacteria

1. prevets osmotic lysis

2. maintains shape

3. barrier to toxic substances

4. contributes to pathogenicity

Name the 2 Peptidoglycan sugars (abbreviations):

NAG

NAM

How does peptidoglycan form crosslinks

using peptide part

third type of cell (not gram positive OR negative)

Acid Fast

Acid fast have slow growth and nutrient uptake due to?

huge, waxy barrier

Nucleoid

region where dna/chromosome hangs out

Capsule function

resist phagocytosis

Pili

attachment

Flagella

motility

chemotaxis

Chemotaxis

movement towards or away from stimuli

Trigger for Endospore formation

lack of food

What is an endospore resistant to

UV, dessication, extreme heat, lack of food

Two important genera of bacteria that form endospores and a disease they cause

Clostridium - tetanus

Bacillus - anthrax

Segregation of chromosome (3 steps) and cytokinesis (1 step)

ParB binds parS

ParA binds ParB - pulls DNA

ParA falls off and new ParA grabs ParB

FitZ squeezes at septation site

Label the Phases of growth

Lag phase

exponential phase

stationary phase

death phase

Lag phase

change in gene expression

exponential phase

max growth / quick divisions

stationary phase

lack nutrients

waste buildup

death phase

decrease in cell number

Bacteria change environmental pH through ______

metabolic changes

three pH types of bacteria

acidophiles

neutrophiles

alkaliphiles

how does pH affect proteins?

change shape and affect how protein interacts with a substrate

pH tolerance mechanisms

transporter - proton pumps

enzyme catalyzed reactions to consume H ion

movement to avoid area of undesired pH

three temperature types of bacteria

psychrophiles

mesophiles

thermophiles

How does temp affect proteins

increases speed until protein denatures

Thermophilic proteins have more connections between ________ to maintain shape

R groups

5 oxygen types of bacteria

obligate aerobe

microaerophile

facultative anaerobe

aerotolerant anaerobe

strict anaerobe

What type of oxygen use is this?

Microaerophile

What type of oxygen use is this?

obligate aerobe

What type of oxygen use is this?

facultative anaerobe

What type of oxygen use is this?

aerotolerant anaerobe

What type of oxygen use is this?

strict anaerobe

Complex media

rich media

poorly defined ingredients

supportive

Defined media

exact chemical formula of each ingredient

slow growth

Enriched media

used to grow fastidious bacteria

Selective media

inhibits growth of certain bacteria

Differential bacteria

distinguishes between bacteria

Theraputic dose

minimum dose that is effective

Toxic dose

minimum dose that is toxic to patient

Therapeutic index

ratio of toxic dose to effective dose

MIC

minimum inhibitory concentration

Disc diffusion assay - Kirby Bauer

diameter of zone of inhibition tells how effective

Larger zone of inhibition, the (more/less) effective a drug is against pathogen

more

E-test

determines minimum inhibitory concentration

5 antibiotic targets:

cell well synthesis

DNA synthesis

RNA synthesis

protein synthesis

Metabolism

2 drugs that inhibit cell wall synthesis

Penicillin

Vancomycin

Penicillin mechanism (Beta lactam)

competitive inhibitor

prevents PBP from forming crosslinks by binding to it

Resistance mechanism of bacteria against beta lactams

Beta lactamase

Vancomycin mechanism (gycopeptide)

steric inhibiter

prevents PBP from forming crosslinks by binding to substrate (D-ala peptide)

ineffective against gram negative

How does PBP form crosslinks?

binds to D-ala on peptide and connects glycan strands

2 Types of Protein synthesis inhibitors

1. aminoglycosides - bactericidal; irreversibly binds to ribosome

2. tetracyclines - bacteriostatic

2 types of Metabolic Antagonists

1. antimetabolites

2. structural analogs

Nucleic acid synthesis inhibition

1. fluoroquinolones - DNA polymerase

2. rifamycin - RNA polymerase

2 types of drug resistance

1. intrinsic

2. acquired

4 Mechanisms of acquired resistance

1. degrade drug

2. modify target

3. pump out drug

4. alternative pathway - get from environment instead