Chapter 3: Cell Structure: Internal Structures

Question 1

What is the cytoplasm?

Answer 1

The substance inside the plasma membrane

Question 2

What is the cytoplasm composed of? (5)

Answer 2

• About 80% water
• contains most of the “stuff” needed for life
• sugars, AA, nucleotides, etc.
• enzymes
• some functional structures

Question 3

What does the nucleoid contain? (3)

Answer 3

• bacterial chromosome (DNA)
• may also contain plasmids
• not surrounded by a nuclear membrane

Question 4

What is a bacterial Chromosome (DNA)?

Answer 4

• all the genetic information required for cell’s structure and functions

Question 5

What are plasmids?

Answer 5

• smaller, double stranded DNA molecules
• contain non-essential genes
  Ex. Genes for antibiotic resistance

Question 6

How do bacteria replicate?

Answer 6

Binary fission

Question 7

How will coiled DNA migrate in gel electrophoresis?

Answer 7

Will not migrate, only linear will migrate

Question 8

What are ribosomes?

Answer 8

• site of protein synthesis

Question 9

What are ribosomes made of?

Answer 9

Protein and rRNA

Question 10

What are the two subunits of bacterial ribosomes, and what do they form? (3)

Answer 10

• 30S subunit
• 50S subunit
• they form the complete 70S ribosome

Question 11

How do ribosomes of bacteria differ from eukaryotic robosomes?

Answer 11

• Eukaryotes have 80S ribosomes

Question 12

What targets bacterial ribosomes? (3)

Answer 12

• several antibiotics
• streptomycin, erythromycin
• prevent the bacteria from making new proteins

Question 13

What are storage granules (inclusion bodies) ?

Answer 13

• usually deposits or granules of nutrients, stored for later use

Question 14

What are some examples of storage granules (inclusion bodies)? (5)

Answer 14

• sulfur granules
• polysaccharides (glycogen)
• lipid inclusions
• enzymes
• magnetite

Question 15

What is the function of storage granules?

Answer 15

• a variety of inclusion bodies occur in different bacterial species
• can serve as a basis for identification

Question 16

What type of bacteria form endospores?

Answer 16

• some Gram positive bacteria

Question 17

What is the function of endospores? (3)

Answer 17

• special resting structure that allows bacteria to enter dormant state
• remains dormant until good growth conditions occur
• thus can form a new population

Question 18

How are endospores extremely durable?

Answer 18

• resists heat, desiccation, chemicals, radiation, etc.
• some endospores can survive in boiling water for hours

Question 19

Give 2 examples of endospores

Answer 19

• bacillus anthracis - causes anthrax
• clostridium botulinum - causes the food borne illness botulism (done by dented cans too)