MICROBIOLOGY EXAM 1 – 7 LATEST REAL EXAM 2024 WITH VERIFIED QUESTIONS AND CORRECT ANSWERS FROM EXPERT

MICROBIOLOGY EXAM 1 – 7 LATEST REAL EXAM 2024 WITH VERIFIED QUESTIONS AND CORRECT ANSWERS FROM EXPERT

function of ribosomes - -protein synthesis
-site of action for aminoglycosides, erythromycin, tetracyclines and chloramphenicol

function of nucleoid - Contains DNA

function of mesosome - cell division and secretion

Function of plasma membrane - site of oxidative and transport enzymes

function of capsule - -protects against phagocytosis
-sticks to cell

Function of pilus or fimbria - (1) sticks to cell
(2) sex pilus attaches 2 bacteria during conjugation

function of flagellum - motility

Function of spore - Provides resistance to dehydration, heat chemicals

Function of plasmid - variety of genes for antibiotic resistance and toxins

Function of granule - site of nutrients in cytoplasm

Function of glycocalyx - adherence to surfaces

Identify 3 components of both gram positive and negative bacteria. - -Cell wall
-Capsule
-Plasma cell membrane

Compare/contrast gram (+) and gram (-) bacteria - Gram (+)
1. thick peptidoglycan
2. small periplasmic space
3. Teichoic acid

Gram (-)
1. THIN peptidoglycan
2. LPS
3. Porins
4. Large periplasmic space

Plasmids carry genes for? - 1. Antibiotic resistance
2. Resistance to heavy metals (Hg, Ag)
3. Resistance to UV light
4. Pili
5. Exotoxins

Bacterial shapes: cocci - - diplococci (pair)
- streptococci
- tetrad (4)
- staphylococci
- Sarcina (cube of 8)

Bacterial shapes: Rods (Bacilli) - -chain of bacilli
-flagellate rods
-spore former

Bacterial shapes: Spirals - -Vibrios
-Spirilla
-Spirochaetes

The shape of a bacterium is determined by its _____. - rigid cell wall

Smallest and largest bacteria - Smallest:
Mycoplasma

Largest: Bacillus anthracis

Bacteria is a prokaryote with the following characteristics : ______ - -no nucleus or membrane-bound organelles
-chromosomes and plasmids freely float in cytoplasm

Function of cells wall - • Provides structural
support
• Made of peptidoglycan
(polysaccharide)

Function of capsule - Sticky outer layer
for protection and
attachment

Function of plasma cell membrane - • Directs what enters
and exits
• Phospholipid bilayer

Differences in cell walls gram (-) and (+) -

Gram positive bacteria structure - • Inner plasma cell membrane (phospholipid bilayer)
• Thick 'peptidoglycan' cell wall
• Outer Capsule

Gram negative bacteria structure - • Inner plasma cell membrane
(phospholipid bilayer)
• Thin 'peptidoglycan' cell wall
• Another outer plasma cell
membrane (phospholipid
bilayer - 'lipopolysaccharides')
• Outer Capsule

Bacteria unlike eukaryotes have no ____ in plasma membrane. - sterols

Lipopolysaccharide (LPS) is only associated with ______. - Gram negative bacteria

POLLEV- True or false: Gram (-) Bacteria has a thicker peptidoglycan cell wall than the Gram (+) Bacteria - False

Essential components of bacteria - -cell wall (peptidoglycan, outer membrane of gram (-) bacteria, surface fibers
-mesosome
-nucleoid
-periplasm
-plasma membrane
-ribosome

Function of peptidoglycan - -rigid support
-protects against osmotic pressure
-penicillin, vancomycin and cephalosporin
acts here

Outer membrane of gram (-) bacteria has Lipid A which is _____ - endotoxin

What are bacterial ribosomal subunits? - 50 s and 30s

A periplasmic space in gram negative is ____ - bigger

Fate of Beta lactamases in gram (+)/(-) bacteria - Gram positive flushes out beta lactamases from small periplasmic space

Gram negative will store beta lactamases in its bigger periplasmic space

Porin channels made up of proteins are outside of ____ bacteria. - gram negative

Most antibiotics that pass through porin channels (made of proteins) are ______. - Hydrophilic

Function of polysaccharide - major surface antigen frequently used in lab diagnosis

function of teichoic acid - major surface antigen rarely used in lab diagnosis; found in gram POSITIVE bacteria

Nonessential components of bacteria - -capsule
-pilus or fimbria
-flagellum
-spore
-plasmid
-granule
-glycocalyx