WEEK 1: Nutrient uptake and metabolism

Question 1

what are conditionally-essential nutrients?

Answer 1

factors that cannot be synthesized fast enough to support growth or maintenance

Question 2

what are non-essential nutrients?

Answer 2

factors that can be produced by the body/do not have defined issues resulting from deficiency. We don’t have a biological drive to consume these.

Question 3

where is the major site of digestion?

Answer 3

small intestine. It requires enzymes from the pancreas

Question 4

why is mechanical digestion important?

Answer 4

it releases nutrients and breaking down matrix structure of food to digest

Question 5

what specialist proteins do hydrophilic nutrients require to cross cell membranes to be absorbed? What is this process called?

Answer 5

Monosaccharides
Amino acids
Ions

Co-transport

Question 6

how does the epithelium support the co-transport of proteins?

Answer 6

produces sodium ions at a relatively high conc. The cellular conc of sodium ions remains low so the process can continue.

Question 7

are lipids hydrophobic or hydrophilic?

Answer 7

hydrophobic

Question 8

what is the function of the thoracic duct?

Answer 8

it transports lymph back into the circulatory system

Question 9

hydrophilic factors go straight to the bloodstream. Where do lipid factors go?

Answer 9

lymphatic system

Question 10

what is the hepatic portal system?

Answer 10

The hepatic portal system is the venous system that returns blood from the digestive tract and spleen to the liver

Question 11

where does the hepatic portal system lead to?

Answer 11

the liver

Question 12

which part of the blood stream do hydrophilic factors go?

Answer 12

hepatic portal system

Question 13

what is a chylomicron?

Answer 13

a large lipoprotein structure

Question 14

what is catabolism?

Answer 14

Catabolism is the breakdown of absorbed substances to their constituent parts which cause the release of free energy and production of ATP and NADH.

Question 15

what is anabolism?

Answer 15

the synthesis of complex molecules, tissues and stores within the body. Requires input of energy to occur.

Question 16

name one organ important in nutrient storage?

Answer 16

liver

Question 17

what is a functional pool?

Answer 17

where nutrients are put to use, eg iron in rbcs

Question 18

what is a storage pool?

Answer 18

where nutrients are stored

Question 19

give an example where functional and storage pools over lap.

Answer 19

Calcium is stored in the bones and also utilised there

Question 20

what stages occur when a nutrient is deficient.

Answer 20

low storage levels –> low tissue levels –> poor biochemical function

Question 21

at what stage do deficiency symptoms appear?

Answer 21

poor biochemical function

Question 22

what 1 vitamin can the body synthesize itself?

Answer 22

vitamin D

Question 23

what is a vitamin?

Answer 23

Organic compounds that are required in small amounts for the normal functioning of the body and maintenance of metabolic integrity. They mostly cannot be synthesized by the body.

Question 24

what foods are a source of vitamin C?

Answer 24

Green vegetables, citrus fruits, potatoes, berries

Question 25

what are some roles of vitamin C? (4)

Answer 25

Collagen formation Formation of adrenaline/noradrenaline Absorption of iron Antioxidant defence

Question 26

what are some water soluble vitamins?

Answer 26

- vitamin C - vitamin B group, this includes: B1 B2 Niacin Biotin Pantothenic acid B6 Folic acid B12

Question 27

where are fat soluble vitamins stored?

Answer 27

in the liver, along side water soluble B12

Question 28

how are fat-soluble vitamins absorbed?

Answer 28

via co-transport alongside dietary fats/lipids

Question 29

what are the fat-soluble vitamins?

Answer 29

Vitamin A (retinol, retinal, retinoic acid) Vitamin D (ergosterol, cholcalciferol) Vitamin E (tocopherol, tocotrienol) Vitamin K (phylloquinone, menaquinone)

Question 30

what are some roles of vitamin A? (4)

Answer 30

Vision pigment Epithelial differentiation Reproduction Possible antioxidant roles

Question 31

what are some roles of vitamin D? (2)

Answer 31

Bone maintenance/calcium homeostasis Proposed roles in immune/inflammatory response

Question 32

what is the role of vitamin E?

Answer 32

Membrane-bound protection against oxidative stress

Question 33

what are some roles of vitamin K? (3)

Answer 33

Blood-clotting Post-translation protein modification Bone development and health

Question 34

what percentage of vitamins are absorbed in the small intestine?

Answer 34

40 - 90 %

Question 35

what do fat-soluble vitamins require to be absorbed?

Answer 35

dietary fats

Question 36

what are minerals?

Answer 36

elements needed by the body in small amounts for health and maintenance.

Question 37

what amount of major/macro minerals are needed?

Answer 37

diet in amounts greater than 100 mg per day or are present in the body in amounts greater than 0.01% of body weight

Question 38

what amount of trace minerals are needed?

Answer 38

diet in amounts less than 100 mg per day or are present in the body in amounts less than 0.01% of body weight.

Question 39

is iron a trace mineral or macro mineral?

Answer 39

trace mineral

Question 40

where is iron stored?

Answer 40

in the liver and enterocytes bound to ferritin

Question 41

what can happen if there is excess or an unbound iron state?

Answer 41

toxicity - can induce free radical formation

Question 42

what percentage of dietary Fe is absorbed?

Answer 42

~10%

Question 43

which is more readily to be absorbed? Fe3+ or Fe2+?

Answer 43

Fe2+ or haem Fe

Question 44

what is transferrin?

Answer 44

a protein that transports iron in circulation

Question 45

what processes does iodine deficiency affect?

Answer 45

thyroid hormones

Question 46

which thyroid hormones in particular are affected by iodine deficiency?

Answer 46

T3 and T4

Question 47

what does the exocrine pancreas digest?

Answer 47

macronutrients

Question 48

what does the endocrine pancreas do?

Answer 48

helps utilise absorbed macronutrients via insulin and glucagon

Question 49

when there are no energy sources for the body (starvation), what is used as a source?

Answer 49

protein in the body starts being utilised

Question 50

insulin drives the synthesis of?...

Answer 50

triglycerides

Question 51

how is fructose (sugar) absorbed by the intestine?

Answer 51

converted into phosphorylated compounds that enter the glycolytic pathway

Question 52

how is galactose (sugar) absorbed by the intestine?

Answer 52

converted into phosphorylated glucose