Digestion And Food

Question 0

Sources and Functions of:

Proteins

Answer 0

We need it for growth and repair of tissue.

Sources - meat, fish, cheese, eggs, beans and nuts

Question 1

Sources and functions of:

Carbohydrates

Answer 1

Body’s main fuel for supplying cells with energy.

Sources: potatoes, rice, wheat

Question 2

Sources and functions of:

Lipids

Answer 2

Form an essential part if the structure of cells and fat is deposited in parts of the body as a long-term store of energy.
Sources - oils, meat, butter, milk, oily fish

Question 3

How villi help absorption

Answer 3

(In the ileum)
Only 1-2mm long, but millions of them. Lots of area in contact with digested food each surface cell also has microvilli, which increase the area for absorption as well.

Question 4

Chemical elements present in:

Carbohydrates

Answer 4

Carbon, hydrogen, oxygen

Question 5

Chemical elements present in:

Proteins

Answer 5

Carbon, hydrogen, oxygen, nitrogen an sulphur

Question 6

Chemical elements present in:

Lipids

Answer 6

Carbon, hydrogen and oxygen

Question 7

The role of enzymes as biological catalysts in metabolic reactions

Answer 7

Enzymes take part in reaction but are unchanged afterwards.

They speed up digestion wit hough being used up themselves. They’re made by tissue and glands.

Question 8

Tests for:

Glucose

Answer 8

Blue Benedict’s solution turns orange-red when heated if simple sugars, like glucose, are present.

Question 9

Tests for:

Starch

Answer 9

Reddish-brown iodine solution turns blue-black if starch is present.

Question 10

Process of absorption

Answer 10

The products of digestion are absorbed into blood stream in the small intestine. Villi in the small intestine are adapted for effective diffusion. They have a large surface area, a good supply to maintain a steep concentration gradient, and short diffusion distances.

Question 11

Process of assimilation

Answer 11

The digested food products are absorbed into the cells of the body by diffusion a be assimilated. They are used for energy and to build into chemicals needed by the cells.

Question 12

Process of Egestion

Answer 12

Water, undigested food, enzymes, dead cells, bile pigments and mucus move through the large intestine. Water is removed. The remaining material is passed out of the anus as faeces.

Question 13

Bile and its role

Answer 13

Bile is produced by the liver and stored in the gall bladder.
It neutralizes stomach acids and emulsifies lipids.

Question 14

Digestion of starch

Answer 14

Amylase - starch to maltose

Maltase - maltose to glucose

Question 15

Digestion of proteins

Answer 15

Protease: proteins to amino acids

Question 16

Digestion of lipids

Answer 16

Lipase: lipids to fatty acids and glycerol

Question 17

How and why food is moved through the gut by peristalsis

Answer 17

Waves of muscle contractions move along the gut, pushing food along. So we don’t need to depend in gravity.

Question 18

Sources and functions of:

Calcium

Answer 18

Making teeth and bones

From - dairy products, fish,

Question 19

Sources and functions of iron

Answer 19

Part of haemoglobin in red blood cells, helps carry oxygen.

From - red meat, liver, eggs

Question 20

Sources and functions of water

Answer 20

Hydration

From - water

Question 21

Sources and functions of dietary fibre

Answer 21

Prevents constipation
Keeps food in the gut moving.
Sources - fresh fruits and vegetables

Question 22

Sources and functions of vitamin A

Answer 22

Making a chemical in the retina

From - liver, butter, margarine

Question 23

Sources and Functions if vitamin C

Answer 23

Sticks together cells lining surfaces such as the mouth.

From - fresh fruit and vegetables

Question 24

Sources and Functions of Vitamin D

Answer 24

Helps bones absorb calcium and phosphate

From - the sun

Question 25

A balanced diet should include appropriate proportions of…

Answer 25

Carbohydrates
Proteins
Lipids
Vitamins
Mineral ions
Calcium
Iron
Water
And dietary fibre

Question 26

Energy requirements vary with..

Answer 26

Age
Activity levels
Pregnancy

Question 27

A balanced diet should include appropriate proportions of…

Answer 27

Carbohydrates
Proteins
Lipids
Vitamins
Mineral ions
Calcium
Iron
Water
And dietary fibre

Question 28

Energy requirements vary with..

Answer 28

Age
Activity levels
Pregnancy

Question 29

Experiment to measure the energy content of food

Answer 29

Use a crisp
Find mass
Add 20cm3 of water to a boiling tube and measure temperature
Mount crisp on needle and put over Bunsen burner until it catches fire
Then put food beneath boiling tube to heat it. Continue to relight food until it can no longer burn.
Measure final temp of water
Energy in joules per gram=
(Temperature difference) x 20 x 4.2 / mass of food