Biological molecules

Question 1

What are the four major classes of biological macromolecules?

Answer 1

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids

Question 2

What is the general composistion of the cell (4 things)? What are their respective percentage proportions?

Answer 2

Question 3

What are carbohydrates used for?

Answer 3

Carbohydrates function as:-

1. Energy storage
2. Fuel
3. Metabolite
4. Structural element

Question 4

What is the general formula for carbohydrates?

Answer 4

(CH2O)n

Question 5

What are the two types of monosaccharides?

Answer 5

1. Ketone based - Ketose
2. Aldehyde based - Aldose

Question 6

Give information about glucose.

Answer 6

• It is an aldose.
• It has 6 carbon atoms - it is a hexose.
• It has a D-configuration - where the hydroxly group is pointed to the right.
• It can exist in a long-chain and ring structure.

Question 7

What is the difference between L and D configuration?

Answer 7

• In L configuration the hydroxyl group on the second last carbon atom is pointing to the left side.
• In D configuration the hydroxyl group on the second last carbon atom is pointing to the right side.

Question 8

What is the difference between alpha and beta glucose?

Answer 8

• In alpha glucose the OH group points downwards.
• In beta glucose the OH group points upwards.

Question 9

Which two monomers make up sucrose?

Answer 9

Glucose and fructose

Question 10

Which two monomers make up lactose?

Answer 10

Galactose and glucose.

Question 11

Give information on glycogen.

Answer 11

• It is an aldose
• It has 6 carbon atoms.

Question 12

What is glycosylation?

Answer 12

It is when a carbohydrate is covalently bonded to an organic molecule to form structures like glycoproteins.

Question 13

What are oligosaccharides?

Answer 13

Oligosaccharides are carbohydrates composed of a relatively small number of monosaccharides (3-6).

Question 14

Explain the primary structure of proteins.

Answer 14

It is when amino acids join together by peptide bonds to form a polypeptide chain.

Question 15

Explain the secondary structures of proteins.

Answer 15

• It is the way in which the primary structure of the proteins folds.
• Hydrogen bonds form to stabilise the structure.
• Can form alpha helixs, beta turns and beta pleated sheets.

Question 16

Explain the tertiary structure of proteins.

Answer 16

• It is the overall 3D structure of the protein.
• It is stabilised by hydrogen bonds, hydrophilic and hydrophobic interactions, disulfide bridges and ionic bonds.

Question 17

Explain the quaternary structure of proteins.

Answer 17

• It is the organisation of macromolecules into assemblies.
• It is often stabilised by ionic bonds.

Question 18

Give information on body fats.

Answer 18

• They act predominanty as food reserves.
• They are glycerol esters witth fatty acids.
• They can be saturated (without double bonds) or unsaturated (with double bonds).

Question 19

How does steroid enter the membrane?

Answer 19

• the OH group interacts with the polar lipid heads.
• Its steroid scaffold interacts with the fatty acids.