quiz 1- week 1/2

Question 1

What is the main difference between prokaryotic and eukaryotic cells?

Answer 1

Prokaryotic cells lack a nucleus and organelles, while eukaryotic cells have them.

Question 2

Why is understanding bacterial structure important in treating infections?

Answer 2

It helps target specific bacterial structures, such as cell walls, for effective treatment.

Question 3

What are the shapes of bacteria?

Answer 3

Spherical (strep - chain of grapes, staph - cluster of grapes) and rod (e.g., E. coli, P. aeruginosa).

Question 4

What evolutionary traits help bacteria survive?

Answer 4

Thick outer envelopes, compact genomes, and tightly coordinated gene expression.

Question 5

What does a Gram stain reveal about bacterial cell walls?

Answer 5

Gram-positive bacteria have a thick peptidoglycan layer; Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane with lipopolysaccharides (LPS).

Question 6

What is the Limulus test used for?

Answer 6

To differentiate between live and dead gram-negative bacteria using horseshoe crab blood.

Question 7

What are the functions of bacterial capsules?

Answer 7

To stick to surfaces and evade the immune system.

Question 8

What is the role of flagella in bacteria?

Answer 8

Movement.

Question 9

What are membrane proteins used for?

Answer 9

Transport, receiving signals, and secreting toxins.

Question 10

What is the function of teichoic acid in Gram-positive bacteria?

Answer 10

It connects peptidoglycan, retains the Gram-positive stain, and acts as an antigen for the immune system.

Question 11

What is peptidoglycan’s role in bacterial cells?

Answer 11

It provides protection from the environment and is a key component of the cell wall, especially in Gram-positive bacteria.

Question 12

What are lipopolysaccharides (LPS) in Gram-negative bacteria?

Answer 12

They communicate with the environment, aid adhesion, and act as an endotoxin for the human immune system.

Question 13

What is septation in bacterial cells?

Answer 13

Physical cell division caused by peptidoglycan growing into the cleavage site.

Question 14

What is the divisome in bacteria?

Answer 14

A protein complex that carries out septation, helping the membrane pinch inward.

Question 15

Where does DNA replication in bacteria start?

Answer 15

At the origin, where the chromosome is attached to the inner membrane.

Question 16

What is mRNA’s function?

Answer 16

Messenger RNA codes for proteins.

Question 17

What is the role of rRNA?

Answer 17

Ribosomal RNA makes up the ribosome, facilitating protein synthesis.

Question 18

What does tRNA do?

Answer 18

Transfer RNA binds specific amino acids to the growing protein chain during translation.

Question 19

What types of RNA have regulatory roles?

Answer 19

siRNA, snRNA, shRNA, miRNA.

Question 20

What is fluorescence microscopy used for?

Answer 20

It uses excitation wavelengths to light up fluorophores and detect emitted light for viewing cells.

Question 21

What is the purpose of electron microscopy?

Answer 21

To visualize bacteria by coating samples in heavy metal, scanning for outside views, or transmitting to see internal structures.

Question 22

What factors influence the choice of TB suppression drugs?

Answer 22

Availability of healthcare and the range of drugs on the market.

Question 23

What is a negative stain?

Answer 23

A simple stain that is not differential, used to increase contrast in microscopic studies.

Question 24

How do eukaryotes handle waste disposal?

Answer 24

Through proteasomes (for cytoplasmic proteins) and lysosomes (for membrane components and membrane-bound proteins).

Question 25

How do bacteria dispose of waste?

Answer 25

Via simple diffusion.

Question 26

What are essential nutrients for bacteria?

Answer 26

Nutrients needed for survival that bacteria cannot synthesize themselves.

Question 27

What are macronutrients?

Answer 27

Building blocks like oxygen, carbon, and nitrogen that are essential for bacterial growth.

Question 28

What are aerobes?

Answer 28

Organisms that require oxygen to survive.

Question 29

What are anaerobes?

Answer 29

Organisms that do not use oxygen. Obligate anaerobes die in the presence of oxygen, while facultative anaerobes can use oxygen when available.

Question 30

What do heterotrophs do?

Answer 30

They break down carbon sources to generate energy.

Question 31

What are organotrophs?

Answer 31

A subset of heterotrophs that use organic molecules as their energy source.

Question 32

How do autotrophs obtain energy?

Answer 32

They harness energy from light or other non-carbon sources to build carbon compounds.

Question 33

What is facilitated diffusion?

Answer 33

The movement of molecules down their concentration gradient, from high to low concentration.

Question 34

What are ABC transporters?

Answer 34

Proteins that use ATP to transport molecules across the cell membrane against their concentration gradient.

Question 35

What is symport in active transport?

Answer 35

Both substrates move in the same direction, one down its concentration gradient, and the other hitches a ride.

Question 36

What is antiport in active transport?

Answer 36

One substrate moves down its concentration gradient, while the other moves in the opposite direction against its gradient.

Question 37

What is a solid culture?

Answer 37

A bacterial colony that originates from a single cell, often grown on agar plates or slants.

Question 38

What is a liquid culture?

Answer 38

Bacteria grown in a nutrient-rich broth.

Question 39

What is a complex medium?

Answer 39

A nutrient-rich medium with poorly defined components.

Question 40

What is a minimal defined medium?

Answer 40

A culture medium with clearly defined ingredients.

Question 41

What is an enriched medium?

Answer 41

A medium with additional components to support the growth of certain bacteria, though it's poorly defined.

Question 42

What is a selective medium?

Answer 42

A culture medium that allows only desired bacteria to grow, e.g., selecting for Gram-negative bacteria.

Question 43

What is a differential medium?

Answer 43

A culture medium where all bacteria can grow, but they appear differently, allowing differentiation, such as between Gram-positive and Gram-negative bacteria.