20. Functions of Macronutrients

Question 1

define a nutrient

Answer 1

a substance that promote normal gorwth, maintanece and repair of the body

Question 2

what is an essential nutrient? give three examples of them

Answer 2

a nutrient that cannot be made by the animal so its essential for consumption

• there are 8 essential amino acids
• essential fatty acids (chain length and double bonds) - omega 3s and 6
• about 100g of carbohydrates a day for a human

Question 3

why is nitrogen importnat in protein?

Answer 3

because the nitrogens in protein as a food are used to synthesise to make amino acids. nitrogen is a necessary componenent of amino acids and protein from food supplies it to the body. needed for protein synthesis!!

Question 4

what are complete proteins and give 3 examples of food sources

Answer 4

they are proteins that have all the 8 essential amino acids needs-

1. eggs
2. milk
3. meat
4. fish

Question 5

what are incomplete proteins and give three examples

Answer 5

proteins that dont have all the essential amino acids in them

1. legumes
2. nuts
3. seeds
4. grains
5. vegetables

Question 6

name 4 functions of proteins in mammals

Answer 6

1. enymes
2. locomotin - muscle proteins
3. structural proteins - skeletal matrix
4. receptors, channels, transporters
5. antibodies
6. binding proteins and transport proteins
7. venoms
8. vision

Question 7

how does protein synthesis occur?

Answer 7

the synthesis of amino acids to form peptide bonds between the amine and carboxyl group. its a all or non reaction - all amino acids must be present at the same time to occur

Question 8

what is nitrogen balance?

Answer 8

the rate of protein syntheses = the rate of breakdown and loss of nitrogen in amino acids

Question 9

what is anabolic and catabolic?

Answer 9

anabolic: building/ promoting protein synthesis
catbolic: breaking down

Question 10

what is a disadvantage of a plant based diet?

Answer 10

most plant proteins are incomplete in amino acid makeup which can lead to protein deficency . need to eat a varitety of plants to get the nutrients in

Question 11

what is the fate of ptoeins during digestion (other that amino acid synthesis)

Answer 11

bioactive peptides can be produced - specific protein fragments that have a positive impact on body functions and affect health

Question 12

what are four roles of lipids?

Answer 12

1. structural role in cell membranes and myelin sheaths
2. major energy fuel of hepatocytes (liver cells) and skeletal muscle
3. stored in adipose tissue
4. reduce water loss
5. absorbtion of fat - soluble vitamins
6. cell signalling

Question 13

what is the most abundant type of lipid?

Answer 13

triglycerides!!

Question 14

what are essential fatty acid?

give two examples of them

Answer 14

they are fatty acids that the body cannot produce and must be consumed through diet.

two examples:

• alpha-linolenic acid (omega 3)
• linoleic acid (omega 6)

the essential part of the fatty acid is the double bond

Question 15

what is the w6:w3 balance?

Answer 15

the ratio of about 4 omega 6: 1 omega 3 fatty acids for optimal health and to avoid inflammatory signals, diabetes, depression etc. omega 6 is to high in our diet

Question 16

what are three funtctional roles of carbohydrates?

Answer 16

1. structural support
2. storage compounds - glycogen
3. transport compounds

Question 17

what is the difference between simple and complex carbohydrates?

Answer 17

simple carbohydrates are monosaccarides
complex carbs are polysaccharides or disaccarides - they take longer to break down and slower absorbed

Question 18

what two parts of the body rely heavily on glucose for energy?

Answer 18

Red blood cells and neurons (aka brain)