Energy and Nutrient Requirements Pt. 1

Question 1

Give an example of an oligosaccharide

Answer 1

Inulin (fructose polymer)

Question 2

Name three monosaccharides

Answer 2

Glucose, galactose, fructose

Question 3

Name three disaccharides

Answer 3

Maltose, sucrose, lactose

Question 4

Name two dietary polysaccharides

Answer 4

Starch, non-starch polysaccharides (NSPs) e.g. dietary fibre

Question 5

What is dietary fibre? Give some examples

Answer 5

Carbohydrates that can’t be digested by human digestive enzymes e.g. cereals, fruits, vegetables, nuts, peas, grains, pulses

Question 6

What is fermentation?

Answer 6

Using carbohydrates to produce short chain fatty acids (e.g. butyrate, acetate, propionate)

Question 7

Why is fermentation important for digestion?

Answer 7

. Has effect on colonic epithelial cells- controls bowel activity/laxation and bowel microflora
. Has bulking effect on stool to speed up movement through bowels

Question 8

What is the glycaemic index of pure glucose?

Answer 8

GI= 100

Question 9

How does the body respond to eating high GI foods?

Answer 9

Blood glucose spikes to high level rapidly then declines quite rapidly

Question 10

How does the body respond to eating low GI foods?

Answer 10

Blood glucose rises to a moderate/low level and falls steadily

Question 11

Give some examples of low GI foods

Answer 11

Fruit, legumes, muesli, oats

Question 12

Give some examples of high GI foods

Answer 12

White bread, instant mashed potato

Question 13

What percentage of total dietary intake should be carbohydrates?

Answer 13

Around 50%

Question 14

What is the recommended maximum intake of free sugars?

Answer 14

No more than 5% (less than 30g a day)

Question 15

Which vitamins are water-soluble?

Answer 15

B and C (think ; BeCause water is best)

Question 16

Which vitamins are fat-soluble?

Answer 16

A, D, E, K

Question 17

Which vitamins are responsible for producing thymidine?

Answer 17

B12 and folate (folic acid)

Question 18

Why is important to intake enough B12 and folate? Which cells are affected by their action?

Answer 18

They produce thymidine, which is involved in DNA synthesis

Because involved in DNA synthesis, particulary affects rapidly dividing cells (e.g. hair follicles, RBCs)

Question 19

Name two sources of B12

Answer 19

Animal products (meat, milk) and yeast

Question 20

Name a source of folate

Answer 20

Green vegetables

Question 21

What can deficiencies in B12 and folate lead to?

Answer 21

. B12- megaloblastic anaemia, neuropathy due to decreased production of myelin
. Folate- anaemia (fewer RBCs produced), neural tube defects

Question 22

Give some sources of vitamin D

Answer 22

Fish oil, egg yolks, UV, margarine

Question 23

In terms of vitamin D, what happens when UV light hits the skin?

Answer 23

. 7- Dehydrocholesterol + UV from sunlight –> Vitamin D3 in skin –> (In blood Vit. D3= Cholecalciferol)
. Calcidol (vit D3 precursor) hydroxylated in kidneys –> calcitriol (active vit. D3)
. Binds to VDRs on target organs

Summary: (7-dehydrocholesterol -> vit D3 in skin -> cholecalciferol -> calcidiol -> calcitriol)

Question 24

What is cholecalciferol?

Answer 24

Vitamin D3 in the blood

Question 25

What is calcidiol?

Answer 25

Precursor of vitamin D3 (in blood)

Question 26

What is calcitriol?

Answer 26

Active vitamin D3 (in blood)

Question 27

How is vitamin D3 from the diet processed in the body?

Answer 27

. Vitamin D3 in form of cholecalciferol -> converted calcidiol in liver
. Calcidiol hydroxylated in kidneys –> calcitriol
. Calcitriol binds to VDRs on target organs