Chapter Eleven : Vitamins and Proteins

Question 1

Metabolism

Answer 1

Chemical processes that involve breaking down and building different substances in the body

Question 2

What do carbs, fats and proteins hydrolyse to?

Answer 2

C- monosaccahrides
P - amino acids
F - glycerol and fatty acids

Question 3

Minerals

Answer 3

Inorganic substances required in various amounts

Question 4

Vitamins

Answer 4

Are a group of organic compounds that are essential for growth and nutrition, cannot be synthesised by the body

Question 5

Proteins

Answer 5

For growth and repair of the cells, immunity and transport of molecules and as enzymes, hormones and structural components

Question 6

Carbohydrates

Answer 6

To store and provide energy, for the functioning of the central nervous system and to remove waste from the body

Question 7

Fat-soluble vitamins

Answer 7

A,D,E,K
Absorbed in the intestines
Stored as fat deposits in the lover
Mostly non-polar

Question 8

Water soluble vitamins

Answer 8

Dissolve within the body as it is polar
8 different B groups and Vitamin C
Absorb directly into the bloodstream
Excreted through the kidneys in the urine
Must be obtained from food on a regular basis

Question 9

Vitamin C - ascorbic acid

Answer 9

Maintains healthy immune system; assists in wound healing; helps the production of collagen
Red peppers, citrus, kiwi, broccoli

Question 10

Roles of protein in the body

Answer 10

Acts as catalysts
Antibodies to prevent infection
Assist with formation of new molecules
Act as hormones
Provide structural components for cells

Question 11

Amino acids

Answer 11

Monomers that contain amino and carboxyl groups

20 amino acids, 9 essential

Question 12

Zwitterions

Answer 12

A dipolar ion containing equal positive and negative charges

A + charge goes on the N and a H is lost from COOH making it COO-

Question 13

Zwitterions in acidic environment

Answer 13

Behaves as a base
Cationic form
Carboxyl groups combine with H+ to make uncharged COOH groups
Gives the ammonium ion a net pos charge of NH3+
<4 pH

Question 14

Zwitterions in basic environment

Answer 14

Anionic form
Behaves as an acid
Ammonium group loses H+ - NH2
Carboxyl loses H+ becomes COO-
>8 pH

Question 15

Formation of proteins

Answer 15

Amino acids combine to form peptides in a condensation reaction
A peptide is a reaction between NH2 and COOH with H2O as a product
May be fibrous (keratin, collagen) or globular (haemoglobin)

Question 16

Structure of proteins

Answer 16

Primary structure - The order of amino acids which are covalently bonded in a polypeptide
Secondary structure - Hydrogen bonding causes the chain to coil, pleat or folds
Tertiary structure - Bonding between the side chains of the amino acids (h binding, dispersion, dipole dipole, Di sulfide, ionic)
Quatenary structure - When different protein molecules link together in a particular spacial arrangement

Question 17

Enzymes

Answer 17

Biological catalysts which lower the activation energy by providing an alternative pathway

Question 18

Difference between inorganic catalysts and enzymes

Answer 18

Inorganic catalysts
- speed up any reaction
Enzymes
- Very specific to what reaction they speed up

Question 19

Structure of enzymes

Answer 19

Enzymes have an active site which the substrate is manoeuvred to
Each shape of the active site is unique meaning it can only take 1 type of substrate

Question 20

Lock and key model

Answer 20

Molecules with complementary shapes fit into active sight and form a product

Question 21

Induced fit model

Answer 21

In the presence of a substrate the active site may change in order to fit the substrate’s shape
It will return to its original shape after being used

Question 22

Coenzymes

Answer 22

Are organic non-protein molecules that assist with the functioning of enzymes
Intermediate transporters of electrons

Question 23

Effect of temperature on enzymes

Answer 23

Each enzyme has optimal temp at body temp which is 37.5c if the temp exceeds this the enzyme will denature
If the temp goes under the reaction rate will slow down significantly but will not harm active site

Question 24

Effect of pH levels on enzymes

Answer 24

Each enzyme has a unique optimal pH if the pH is altered either above or below the enzyme will denature

Question 25

Denaturation

Answer 25

The collapse of intra and inter molecular bonds that maintain the shape in secondary, tertiary and quartenary structures of a protein
It alters the shape of the active site destroying catalytic activity

Question 26

Effect of concentration on enzymes

Answer 26

When the concentration of enzymes increase the rate of reaction increases proportionally
When concentration of substrates increase rate of reaction increases until a point of saturation as the active sites become saturated