L11. Proteins, Polysaccharides and Lipids

Question 1

Describe the appearance of alpha helices and how they are stabilised.

Answer 1

Single stranded rods which are stabilised by H bonds

Question 2

Describe the appearance of a beta pleated sheet.

Answer 2

Made of chains running in the same direction (parallel) or opposite direction (antiparallel).

Question 3

Describe where a triple helix is found and what it looks like.

Answer 3

Only found in collagen.

Hydrogen bonds connect different strands together.

Question 4

Are fibrous proteins soluble?

Answer 4

No

Question 5

Give 3 examples of fibrous proteins.

Answer 5

Elastin, collagen, keratin

Question 6

Are globular proteins soluble?

Answer 6

Yes

Question 7

Give an example of a globular protein.

Answer 7

Enzymes

Question 8

Name the 3 types of membrane protein.

Answer 8

1. Integral
2. Peripheral
3. Channel

Question 9

What do carrier proteins do?

Answer 9

Bind to molecules which have to be transported by facilitated diffusion

Question 10

Describe how the binding of a protein to a receptor causes events inside the cell.

Answer 10

Hormone/messenger protein binds to receptor
message relayed to inside the cell
cascade of events
cellular action eg insulin release

Question 11

In muscle contraction, myosin and actin are present. Which is globular and which is fibrous?

Answer 11

Myosin - fibrous

Actin - globular

Question 12

Describe the 2 forms glucose may be present in.

Answer 12

Linear chain

Ring form

Question 13

What does the dehydration of monosaccharides result in?

Answer 13

Complex carbohydrates

Question 14

Saturated fat + fatty acid = ?

Answer 14

solid at room temperature (eg butter)

Question 15

Unsaturated fat + fatty acid = ?

Answer 15

Liquid at room temperature (eg oil)