Metabolism - Lecture Twenty-Six

Question 1

How do we know if we get enough vitamins and minerals from the foods we eat?

Answer 1

Clinical examination, anthropometry, biochemical tests and dietary assessment

Question 2

Clinical examination

Answer 2

Look for symptoms

Question 3

Anthropometry

Answer 3

Energy balance/growth

Question 4

Dietary assessment

Answer 4

Measure what you eat (record or recall or questionnaire)
Convert foods into nutrients (food composition database)
Compare with Nutrient Reference Values

Question 5

Individuals, Groups or National samples

Answer 5

Adult Nutrition Survey, the last one was done 2008/09

Question 6

Vitamin characteristics

Answer 6

“Vital to life” or “vital amines”
Essential, individual, organic molecules
Do not provide energy when broken down
If absent or low in the diet, symptoms of deficiency appear
Required in the diet in small amounts i.e. μg or mg
Bioavailability = amount absorbed and used

Question 7

Fat soluble vitamins

Answer 7

Vitamins A, D, E and K

Question 8

Water soluble vitamins

Answer 8

Vitamin C and all B

Question 9

B1

Answer 9

Thiamin

Question 10

B2

Answer 10

Riboflavin

Question 11

B3

Answer 11

Niacin

Question 12

B5

Answer 12

Pantothenic acid

Question 13

B6

Answer 13

Pyridoxine

Question 14

B7

Answer 14

Biotin (Vitamin H)

Question 15

B9

Answer 15

Folate (folic acid)

Question 16

B12

Answer 16

Cobalamin

Question 17

Roles of vitamins and minerals

Answer 17

Coenzymes, cofactors, structural, antioxidants, DNA/RNA

Question 18

Coenzymes

Answer 18

Organic carrier molecules

Question 19

Cofactors

Answer 19

Participate in catalysis

Question 20

Venous pooling and oedema: heart failure

Answer 20

Beriberi

Question 21

Cerebral beriberi and psychosis

Answer 21

Wernicke-Korsakoff

Question 22

Part of co-enzyme thiamin pyrophosphate

Answer 22

Pyruvate ➝ Acetyl CoA
CA cycle
Role in nerve cells

Question 23

Deficiency in thiamin

Answer 23

Glucose ≠ Energy
Increase in Pyruvate and Lactate: vasodilators
Venous pooling and oedema: heart failure ➝ Beriberi
Cerebral beriberi and psychosis ➝ Wernicke-Korsakoff

Question 24

Wernicke-Korsakoff

Answer 24

Alcoholics, flour fortified with thiamin in Australia and NZ

Question 25

Beriberi

Answer 25

'Polished risk' (germ and bran removed) provided 80% of energy in Cambodia and diversify diet

Question 26

Randomised controlled trial

Answer 26

Highest level of evidence Placebo (control group) vs Treatment Randomised, Double Blind Outcomes (biochemical, clinical, diet)

Question 27

Minerals

Answer 27

Essential, non-organic elements Do not provide energy If absent or low in the diet, symptoms of deficiency may appear Required in the diet in small amounts i.e. μg or mg Bioavailability = amount absorbed and used

Question 28

Roles of minerals

Answer 28

``` Cofactors Structural role Key constituent of Molecules Transfer of electrons Nerve impulse and muscle contraction Fluid and electrolyte balance ```

Question 29

Transfer of electrons

Answer 29

Oxidation:reduction reactions

Question 30

Structural role

Answer 30

Hydroxyapatite crystal: Ca5(PO4)3(OH)

Question 31

Magnesium deficiency

Answer 31

Cofactor >300 enzymes involved in myraid of cellular processes Stabilises proteins, nucleic acids, membranes Electrolyte Bone metabolism and remodelling Nerve impulse and muscle contraction

Question 32

Cofactor >300 enzymes involved in myraid of cellular processes

Answer 32

Chelates to ATP (kinases) Enzymes requiring water, acts as carrier CHO metabolism (glycolysis, glucose homeostasis, insulin action) Lipid, protein and nucleic acid synthesis