Nutrients and Macromolecules

Question 1

Define nutrients

Answer 1

chemicals taken into body to produce ATP, maintains homeostasis, provide building blocks to create other molecules (amino acids)
> carbohydrates, proteins, lipids, vitamins, minerals, water

Question 2

Macromolecules

Answer 2

carbs, proteins, and lipids - major organic nutrients, required in large amounts by the body

Question 3

Vitamins and minerals

Answer 3

Smaller molecules, requires less of them, enter body without being digested

Question 4

Carbohydrates

Answer 4

Most come from plants
Contain carbon, hydrogen and oxygen
2H and 1O for every C
Large molecules made up of small building blocks (monosaccharides)

Question 5

Monosaccharides

Answer 5

• glucose - blood sugar
• fructose - fruit
• galactose - milk

Question 6

Disaccharides

Answer 6

• sucrose - glucose and fructose
• lactose - glucose and galactose
• maltose - glucose and glucose

Question 7

Polysaccharides

Answer 7

Long chains of 3000+ monosaccharides

- glycogen, starch and cellulose

Question 8

Glycogen - polysaccharides

Answer 8

> animal polysaccharides
> glucose molecules
> stored in humans in liver and muscle

Question 9

Starch and cellulose - polysaccharides

Answer 9

> plant polysaccharides
> starch broken down into energy
> cellulose - dietary fibre; can’t be broken down

Question 10

Digestion of polysaccharides

Answer 10

saliva (oral cavity), pancreatic amylase (duodenum)

Question 11

Digestion of disaccharides

Answer 11

digested by enzymes in the intestine

Question 12

Digestion of monosaccharides

Answer 12

glucose absrobed into blood via villi; transported to liver via hepatic portal vein

Question 13

Carbohydrates - uses in the body

Answer 13

• glucose - ATP
• excess glucose - glycogen and stored in muscle and liver cells
• excess beyond storage - fat

Sugars also make up DNA, RNA, ATP, glycoproteins, glycolipids (plasma membrane)

Question 14

Proteins

Answer 14

Contains carbon, hydrogen, oxygen and nitrogen (sometimes sulphur)
Made of amino acids - amine group (NH2), carboxyl group (COOH) and side group (differs between AA)
AA link together to form peptides and proteins

Question 15

Essential amino acids

Answer 15

can’t be produced by the body; must be absorbed through diet (9 in total - eg. histodine)

Question 16

Non-essential amino acids

Answer 16

Can be synthesised from essential aa’s - still required by the body

Question 17

Peptide bonds

Answer 17

covalant bonds formed between aa’s during protein synthesis

Question 18

Digestion of protein

Answer 18

pepsin in stomach

Question 19

Digestion of polypeptides

Answer 19

trypsin in duodenum, villi/microvilli

Question 20

Digestion of amino acids

Answer 20

Into blood via villi/microvilli

Question 21

Proteins - uses in the body

Answer 21

Regulates body functions:

• globular proteins
• structural - muscle proteins
• cell membrane transport
  
  • enzymes
  • hormones
  • antibodies

Question 22

Complete proteins

Answer 22

Contains enough of all essential aa’s

- fish, poultry, milk

Question 23

Incomplete proteins

Answer 23

Must mix to get all aa’s

- green veges, grains, legumes

Question 24

Lipids

Answer 24

C, H, O - sometimes nitrogen and phosphorus
> lower O:C compared to carbs - insoluable in water
Lipids/fats broken down into energy

Question 25

Triglycerides

Answer 25

Glycerol and 3 fatty acids - makes up 95% of fats in the body
Different lengths (14/18 C atoms)
Saturation depends on number of H atoms on each chain

Question 26

Saturated fats

Answer 26

come from animal fats

Question 27

Unsaturated fats

Answer 27

Plant fats

Question 28

Monounsaturated fats

Answer 28

olive and peanut oil

Question 29

Polyunsaturated fats

Answer 29

sunflower and fish oil

Question 30

Transfat

Answer 30

unsaturated fats artificially altered to be more saturated (increases shelf life)

Question 31

Lipid digestion

Answer 31

Begins in duodenum - bile from gall bladder emulsifies fats
Lipase from pancreas - further breakdowns
Monoglycerides absorbed into lymphatic system via lacteals
Stored in adipose tissue and liver until needed

Question 32

Lipids: function in the body

Answer 32

• Triglycerides - produce ATP (excess stored in adipose, liver)
• Cholesterol - component of plasma membranes, modified to form bile salts
• Phospholipids - major components of plasma membranes, myelin sheath, part of bile
• Eicosanoids - derived from fatty acids; involved in inflammation, blood clotting, tissue repair, smooth muscle contraction

Question 33

Water absorption

Answer 33

~9L enters digestive tract each day
99% of water entering intestine is absorbed
Can move across the intestinal wall in either direction
Ions (sodium, potassium, calcium, magnesium, phosphate) activity transported

Question 34

Vitamins

Answer 34

Organic molecules in small quantities in food
Essential for normal metabolism; can’t be produced in body (vitamin C)
Some vitamins produced by intestinal bacteria (vitamin K)
Can be fat soluble (A, D, E, K); water soluble (B, C)

Question 35

Excess vitamins

Answer 35

> vit c - stomach inflammation
vit a - toxic during pregnancy
vit b - beriberi

Question 36

Minerals

Answer 36

Inorganic nutrients

Components of co-enymes, some vitamins, haemoglobin, organic molecules

Question 37

Major minerals

Answer 37

major minerals >100mg/day (calcium, magnesium, sodium, potassium)

Question 38

Trace minerals

Answer 38

trace minerals < 100mg/day (selenium, zinc, copper)

Question 39

Minerals: uses in the body

Answer 39

• membrane and action potential

- adds mechanical strength to bones and teeth

Question 40

Mineral deficiency

Answer 40

> iron - anaemia
potassium - muscle weakness, abnormal heart function
iodine - goitre (hypothyroidism