1.3 Classifications and structure of prokaryotic cells

Question 1

What are the 3 domains of prokaryotic cells?

Answer 1

1. Archaea
2. Bacteria
3. Eukarya

Question 2

What are the 3 bacterial shapes and describe the shape?

Answer 2

1. Cocci - spherical shape
2. Bacilli - rod shaped
3. Spirilli - spiral shaped

Question 3

What is an obligate aerobe?

Answer 3

Requires oxygen for metabolism

Question 4

What are the 3 types of anaerobes?

Answer 4

1. Obligate anaerobes - cannot survive in oxygen environment
2. Facultative anaerobes - can switch between metabolic processes
3. Aerotolerant anaerobes - unable to use oxygen but are unharmed by it

Question 5

Gram positive cell wall turns what colour in the gram staining process?

Answer 5

Deep purple

Question 6

Gram negative cell wall turns what colour in gram staining process?

Answer 6

Pink-red

Question 7

Name three differences between gram positive and gram negative cell wall.

Answer 7

Gram positive

• thick layer of peptidoglycan
• contains lipoteichoic acid

Gram negative

• thin layer and small amounts of peptidoglycan
• contain lipopolysaccarides
• greater inflammatory response

Question 8

1. Prokaryotic ribosomes have _____________ subunits

2. Eukaryotic ribosomes have ___________ subunits

Answer 8

1. 30s and 50s

2. 40s and 60s

Question 9

What are the three recombination processes of prokaryotic cells?

Answer 9

1. Transformation
2. Conjugation
3. Transduction

Question 10

What are the four phases of bacteria growth?

Answer 10

1. Lag phase
2. Exponential phase/log phase
3. Stationary phase
4. Death phase

Question 11

What is a retrovirus and what is an example of one?

Answer 11

• carries out transcriptase - synthesizes DNA from single stranded RNA
• DNA is integrated into host’s genome and replicated as if it were the host’s own DNA - allows cell to be infected indefinitely
• to kill the virus, you have to kill the infected cell
• ex. HIV virus

Question 12

What is the viral life cycle?

Answer 12

1. Infection
2. Translation and progeny assembly
3. Progeny release
4. Lytic and lysogenic cycle (not all viruses will go through these cycles)

Question 13

What is a prion?

Answer 13

• infectious proteins that are non-living

- triggers the misfolding of proteins = interference with cell functioning

Question 14

What is a viroid?

Answer 14

• small pathogens that infect plants

- prevents synthesis of proteins by silencing genes = metabolic disruption and structural damage