4.1 Bacteria

Question 1

Aseptic technique:

Answer 1

• Wipe surfaces clean with antiseptic spray
• tie up hair
• washing hands with antibacterial soap
• flame neck of bottle to sterilise
• opening Petri dish only big enough for pouring the agar jelly in
• sellotaping Petri dish shut
• open bacterial bottle with little finger, reduce contamination

Question 2

What is the cell wall made up of?

Answer 2

-peptidoglycan (carbohydrates & amino acids)

Question 3

What is the function of the cell wall?

Answer 3

• to keep some substances out and stops cell from bursting (osmosis) and holds it in shape

Question 4

What are ribosomes made of?

Answer 4

-RNA and protein

Question 5

Function of ribosomes?

Answer 5

Protein synthesis

Question 6

What is the plasma membrane made of?

Answer 6

Phospholipids an proteins

Question 7

Function of the plasma membrane ?

Answer 7

Partially permeable, controls what molecules leave or enter the cell

Question 8

What is the slimy capsule?

Answer 8

A slimy layer outside he cell wall of some bacteria only

Question 9

What is the function of the slimy capsule?

Answer 9

To protect the cell from drying out, makes cells slippery so it is harder for white blood cells to engulf them

Question 10

What is the flagellum?

Answer 10

Found only in some bacterial cells, rigid and corkscrew

Question 11

What is the function of the flagellum?

Answer 11

For locomotion, rotates from the base and helps the bacterium to move through fluids

Question 12

What is the plasmid?

Answer 12

Small, circular piece of DNA found in some bacteria cells only

Question 13

Function of plasmid?

Answer 13

Carries genes in addition to those in the main nuclear material, e.g. Carries genes that code for enzymes to destroy antibiotics

Question 14

What is circular DNA?

Answer 14

Long circular DNA molecule with no proteins attached to it

Question 15

Function of circular DNA ?

Answer 15

Carries genes for the proteins the cell needs to grow and reproduce