Nutrients

Question 1

Carbohydrates

Answer 1

Monosaccarides (simple sugars-glucose, fructose, galactose, ribose, deoxyribose) and disaccharides-two monos combined with loss of water (sucrose=glucose+fructose, lactose=glucose+galactose, maltose=glucose+glucose)- (milk, honey, fruits), polysaccharides (many monos- starch, glycogen, cellulose)- ( grains, legumes, root vegetables)

Convert into glucose which is used to make up ATP. Excess is converted to glycogen (stored in liver and muscle) or fat (stored as adipose tissue)

Daily intake 125-175gms

Question 2

Protein

Answer 2

Consist of amino group, carboxyl group and side chain r group.

Amino acids, dipeptides (2xaminos), tripeptides (3x aminos), polypeptide (10x aminos)

Structure of proteins= primary-single chain, secondary- helix/B sheet, tertiary- globular, quanternary- more than one tertiary

Complete (egg, milk, meat)- amino acids used for tissue growth and maintenance.

Incomplete (legumes, grains, cereals, vegetables)- lack one or more amino acid essential for building complete proteins

Used to build structures in the body such as skin, collagen, elastin, muscle, enzymes, haemoglobin, plasma proteins, and some
Hormones

Recommended intake 64g men, 46gms women

Question 3

Fats

Answer 3

Triglycerides (fats and oils-glycerol and fatty acid chains) =hydrophobic

Saturated- animal products, plant products
Unsaturated- seeds, nuts, vegetable oils
Cholesterol- eggs, milk products, meats

Phospholipids- glycerol, 2x fatty acid chains + phosphate group. Polar heads and non polar tails=hydrophilic

Necessary for part of the structure and function of the body
Phospholipids are part of cell membrane
Triglycerides major energy source for hepatocytes and skeletal muscle
Dietary fats facilitate absorption of fat soluble vitamins
Linoleic avid (essential fatty acid) helps form prostaglandins, regulates molecules that assist in smooth muscle co reaction, maintenance of blood pressure, control of inflammatory response
Cholesterol essential component of bile salts, steroid hormones and Vit D
Adipose tissue protects body organs, layer of insulation under skin

Question 4

Vitamins

Answer 4

Facilitate use of carbohydrates, fats and proteins
All vitamins must be ingested in food except for Bit D ( ultraviolet irradiation of cholesterol molecules under skin) and Vit K (synthesised by bacteria in intestines)

Fat soluble ( A, D, E, K)- bind to ingested fats and are absorbed as fats are absorbed- excess stored in body and may cause toxicity

Water soluble ( B complex and C)- absorbed with water in GI tract- excess excreted in urine

Vit B12 must be attached to intrinsic factor to be absorbed

Question 5

Minerals

Answer 5

Work with other nutrients to maintain structure and function of the body

Calcium, phosphorus, potassium, sulphur, sodium, chloride, magnesium, iron, iodine, copper, zinc

Source is vegetables, legumes, meats, milk

Question 6

Steroids

Answer 6

Anabolic, sex hormone (estrogen, progesterone, corticosteroids (mineralocorticoids-influence salt and water balance + glucocorticoids- metabolism of glucose and immune function), phytosteroids (steroid alcohols), cholesterol (precursor of steroids and Vit D), prostaglandins (local hormones, chemical messengers that don’t move sites, involved in defence mechanisms and blood clotting), phospholipids

Question 7

Nucleic acids

Answer 7

Monomers=neucleotides=pentode sugar, phosphate, nitrogen base-purines (adenine+guanine) + pyrimidines (cytosine + thymine + uracil)

Question 8

DNA

Answer 8

DNA- Deoxyribose- storage of genetic info
Thymine + guanine with cytosine

RNA- ribose- direct protein synthesis

Uracil + guanine with cytosine