Nutrition and macromolecules

Question 1

Why are chemicals taken into the body

Answer 1

To produce energy and provide building blocks to build other molecules.

Question 2

What are the six classes of nutrients

Answer 2

Carbohydrates, Proteins, Lipids, Vitamins, Minerals, Water

Question 3

Do you need large or small amounts of the six classes?

Answer 3

Large amounts of carbohydrates, proteins, lipids and water.

Small amounts of vitamins and minerals.

Question 4

Describe essential nutrients

Answer 4

Chemicals that must be taken into the body because we can’t make them ourselves. Include some amino acids/fatty acids/carbs, water, most vitamins and minerals.

Question 5

What are the recommended amounts of carbohydrates, lipids and proteins

Answer 5

Carbohydrates: 60%
Lipids: 30%
Proteins: 10%

Question 6

Describe carbohydrates

Answer 6

Most come from plants (Exception of lactose from milk). 2H and 1O for every carbon. Monosaccharides, Disaccharides and Polysaccharides.

Question 7

Three examples of monosaccharides

Answer 7

Glucose, Fructose and Galactose

Question 8

Two examples of disaccharides

Answer 8

Sucrose (Glucose and fructose) and Lactose (Glucose and galactose).

Question 9

Two examples of polysaccharides

Answer 9

Long chains of many sugars (3+ to 3000). Glycogen, starch and cellulose.

Question 10

Describe carbohydrate absorption

Answer 10

Polysaccharide: Digested by saliva in oral cavity and pancreatic amylase in duodenum.
Disaccharide: Digested by enzymes in the intestine (Sucrase for sucrose)
Monosaccharide: Absorbed into blood via villi/microvilli in the intestine.

Question 11

List the uses of carbohydrates in the body

Answer 11

Glucose –> Produces ATP
Excess glucose –> Glycogen and stored in muscle and liver cells
Excess beyond storage is converted into fat
Sugars also become part of DNA and RNA

Question 12

What is a triglyceride made up of

Answer 12

3 fatty acids and one glycerol

Question 13

What do proteins contain

Answer 13

Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulphur. CHONS.

Question 14

What are the basic building blocks of proteins

Answer 14

Amino acids

Question 15

What are the basic building blocks of carbohydrates

Answer 15

Monosaccharides

Question 16

What groups do each amino acid contain

Answer 16

An amine group (NH2), a carboxyl group (COOH) a hydrogen and a side group. The side group is what is different between the amino acids.

Question 17

What are the functions of proteins

Answer 17

Regulate body functions, structural, cell membrane transport, enzymes, hormones, antibodies.

Question 18

What are essential amino acids

Answer 18

Can’t be produced by the body and need to be regularly consumed. 9 in total.

Question 19

What are non-essential amino acids

Answer 19

Still required from our body but can synthesise from essential amino acids

Question 20

Describe complete and incomplete protein sources

Answer 20

Complete: Foods that contain enough of all nine essential amino acids. E.g meat, fish, poultry, eggs, milk, cheese.
Incomplete: Don’t contain all 9 essential amino acids. Legumes, grains, vegetables.

Question 21

Describe protein absorption

Answer 21

Digested in the stomach by pepsin. Protein is broken into polypeptides digested by trypsin in the duodenum. Peptides and individual amino acids are absorbed into the blood via villi and microvilli in the small intestine.

Question 22

What do lipids contain

Answer 22

Carbon, hydrogen, oxygen, nitrogen and phosphorous. CHONP.

Question 23

Describe saturated and unsaturated triglycerides

Answer 23

Presence or absence of double bond.
Saturated: No double bonds. E.g animal fats such as beef, pork, milk, cheese and butter.
Unsaturated: One or more double bonds. E.g olive oil from avocado.

Question 24

Explain trans fats

Answer 24

Unsaturated fats that are artificially altered to have more saturation (more hydrogen). E.g fast food and deep frying.

Question 25

Explain monounsaturated and poly-unsaturated

Answer 25

mono: One bond. Olive oil, peanut oil.
poly: Two or more double bonds. E.g sunflower, fish oils.

Question 26

Explain lipid absorption

Answer 26

Digestion begins in the duodenum. Bile from the gal bladder emulsifies lipids. Lipase from the pancreas causes further breakdown. Short chain fatty acids (monoglycerids) are absorbed into the lymphatic system via lacteals. Lipids are stored in the adipose tissue and liver until needed.

Question 27

What are the uses of lipids in the body

Answer 27

Used to produce ATP.
Cholesterol: Component of plasma membranes.
Phospholipids: Major component of plasma membranes, myelin sheath and part of bile
Eicosanoids: Derived from fatty acids. Involved in inflammation, blood clotting, tissue repair, smooth muscle contraction.