C: Diet & Digestion

Question 1

Absorption

Answer 1

Uptake of digested food molecules from the gut into the body (via the bloodstream or lymph). Mainly happened in small intestines.

Question 2

Amino acids

Answer 2

Molecules which form the building-blocks of proteins.

Question 3

Amylase

Answer 3

Enzyme that digests starch (eventually to glucose), produces by both salivary glands and pancreas.

Question 4

Assimilation

Answer 4

The incorporation of the products of digestion into the body, where they are used to provide energy or for growth and repair of tissues.

Question 5

Benedict’s solution/test

Answer 5

Test for glucose (or other ‘reducing sugars’). The sample is mixed with Benedict’s solution and heated to >90C. If an orange/red precipitate is formed the result is positive.

Question 6

Bile

Answer 6

Green liquid produced in the liver and stored in the gall bladder, which contains alkali to neutralise stomach acid, and bile salts to emulsify lipids, increasing their surface area for faster digestion.

Question 7

Carbohydrase

Answer 7

Enzyme (e.g. amylase) that breaks down carbohydrates.

Question 8

Carbohydrate

Answer 8

Food belonging to the group consisting of sugars, starch and cellulose. They are vital for energy in humans and will be stored as fats if eaten in access. In plants, carbohydrates are produces by photosynthesis.

Question 9

Colon

Answer 9

The large intestine, where water is absorbed into the blood.

Question 10

Denature/denaturation

Answer 10

Inactivation of an enzyme (e.g. with heat) by putting its active site ‘out of shape’ so it no longer fits the substrate.

Question 11

Digestive system

Answer 11

System of organs are involved with the ingestion, digestion, absorption of food.

Question 12

Duodenum

Answer 12

The first part of the small intestine; site of digestion and absorption. Receives bile from the liver and pancreatic juice from the pancreas.

Question 13

Egestion

Answer 13

Getting rid of undigested material from the body; = defaecation.

Question 14

Emulsified

Answer 14

Converted into tiny droplets (e.g. by Bile).

Question 15

Enzyme

Answer 15

Proteins which catalyse chemical reactions inside our bodies. Enzymes are a vital in chemical digestion of food in the gut.

Question 16

Fats

Answer 16

Fats are the more solid lipids.

Question 17

Fatty acids

Answer 17

Long-chain molecules made up of hydrogen and carbon atoms.

Question 18

Fibre

Answer 18

Non-digestible carbohydrates. Fibre is essential as a bulking agent to help food pass quickly and easily through the bowel. A lack of fibre in the diet can lead to constipation, and increased risk of cancer.

Question 19

Glucose

Answer 19

A simple sugar made by the body from food, which is used by cells to make energy in respiration.

Question 20

Glycerol

Answer 20

A soluble carbohydrate which is converted into glucose by the liver.

Question 21

Ileum

Answer 21

The longest part of the small intestine, where food is completely digested.

Question 22

Ingestion

Answer 22

Intake of food.

Question 23

Iodine solution/test

Answer 23

Test for starch in which iodine solution (I2 dissolved inn KI) is dripped on the sample. A blue-black colour is positive.

Question 24

Lipase

Answer 24

Enzyme which digests lipids into fatty acids and glycerol. mainly produced by the pancreas.

Question 25

Lipids

Answer 25

One of the maid food groups, including fats and oils. Lipids are used for energy and insulation. Usually made of glycerol & fatty acids.

Question 26

Liver

Answer 26

Organ which constitutes the largest gland in the body. It produces bile to aid the digestion of fats, stored glucose in the form of glycogen, and helps break down protein and carbohydrates.

Question 27

Mineral ions

Answer 27

Minerals needed by the body which are absorbed as charged ions ( e.g. Ca2+ and Fe3+) and not as part of proteins, fats or carbohydrates.

Question 28

Oesophagus

Answer 28

Tube from the mouth to stomach; food is moved along it by peristalsis.

Question 29

Oils

Answer 29

The more liquid types of lipids.

Question 30

Peristalsis

Answer 30

Wave-like muscular contractions in the smooth wall of the gut which move food through the alimentary canal. Also happens in sperm ducts during ejaculation of sperm.

Question 31

Proteins

Answer 31

Organic compounds made up of amino acid molecules. One of the three main food groups, proteins are needed by the body for cell growth and repair.

Question 32

Protease

Answer 32

Type of enzyme which digests proteins to amino acids. Different proteases are adapted to conditions in the stomach (pepsin) and duodenum (trypsin).

Question 33

Saliva

Answer 33

Fluid secreted by glands in the mouth which moistens and softens food. It contains the enzyme amylase which digests starch, and turn it back into glucose when it is needed for respiration.

Question 34

Starch

Answer 34

A type of carbohydrate. Plants can turn the glucose produced in photosynthesis into starch for storage, and turn it back into glucose when it is needed for respiration.

Question 35

Substrate

Answer 35

A substance on which enzymes act.

Question 36

Sugar

Answer 36

Soluble, sweet-tasting carbohydrate (e.g. glucose, sucrose)

Question 37

Villi ( singular = villus)

Answer 37

Minute finger-like projections which cover the lining of the small intestine, They aid digestion by greatly enlarging the gut’s surface area.

Question 38

Vitamins

Answer 38

Organic substances which are essential in small amounts to regulate the metabolism and maintain the immune system. Named by letter, e.g. Vitamin C (=ascorbic acid) promotes healthy gums & prevents scurvy.