Biology - Week 10 Assessment

Question 1

Name the main biological molecule in a prokaryotic cell membrane. (1)

Answer 1

Phospholipid

Question 2

Name the main biological molecule in a prokaryotic cell wall. (1)

Answer 2

Murein

Question 3

Describe how a saturated fatty acid differs in molecular structure from an unsaturated fatty acid. (2)

Answer 3

• There’s no double bond in a saturated fatty acid chain
• So it can’t accept any more hydrogen

Question 4

What does Fluid Mosaic mean?

Answer 4

• Fluid - molecules can move around freely
• Mosaic - it’s made of many different molecules (proteins and phsopholipids)

Question 5

Lyxose is a sugar. It binds to enzyme and makes the rate of reaction go faster. Without lyxose rate of reaction is slower. Explain why. (3)

Answer 5

1) Lyxose binding to enzyme alters the tertiarty structure of enzyme
2) This causes active site to change
3) So more Enzyme-Substrate complexes form more quickly

Question 6

Describe how the structure of glycogen is related to its function. (4)

Answer 6

• It’s coiled so it’s compact
• More branched so more ends for easier hydrolysis for enzymes
• Glucose polymer provides respiratory substrate for energy
• Insoluble so isn’t affected by osmosis

Question 7

What happens in Prophase, Metaphase and Anaphase? Describe the role of the spindle fibres and behaviour of chromosomes during each of these phases. (5)

Answer 7

1) Prophase - chromosomes condense
2) Metaphase - spindle fibres attach to spindle fibres
3) Metaphase - chromosomes line up at equator
4) Anaphase - cell divides
5) Anaphase - chromatids pulled to opposite ends