Nutrition

Question 1

What should a balanced diet include?

Answer 1

appropriateproportionsof
carbohydrate,protein,lipids,vitamins,
minerals,wateranddietary
fibreascomponentsofthediet

Question 2

Describeanexperimenttoinvestigatethe
energycontentinafood
sample.

Answer 2

Hold a piece of food under a tube of water, burn the food. When it is fully burned compare the heat of the temperature before and after. The change in heat is the energy in degrees

Question 3

Describetheprocessesofingestion,
digestion,absorption,
assimilationandegestion

Answer 3

Digestion: process in which large insoluble molecules of food are broken down into smaller ones.

Absorption: the process by which soluble molecules produced by digestion are taken from the gut (occurs mostly in the small intestine.) The soluble products of digestion are then transported to the various tissues by the circulatory system.

Assimilation: the cells of the tissues absorb the molecules for use.

Egestion: removal of waste- undigested- products as faeces.

Excretion: removal of waste products that have been in the body.

Question 4

Peristalsis

Answer 4

This is where the muscles contract in and out to squeeze food through the gut

Question 5

What is the human alimentary canal made up of?

Answer 5

Mouth, oesophagus, stomach, small intestine and large intestine

Question 6

Where does ingestion take place?

Answer 6

In the mouth

Question 7

What is bile?

Answer 7

A liquid, produced by the liver and stored in the gall bladder, which is highly alkaline and emulsified lipids.

Question 8

What is a catalyst?

Answer 8

A substance that increases the rate of a chemical reaction, such as an enzyme

Question 9

What is chemical digestion?

Answer 9

The breakdown of large molecules into smaller ones using enzymes

Question 10

What is chlorophyll?

Answer 10

The green chemical in chloroplasts that captures light energy for photosynthesis?

Question 11

What does it mean to emulsify?

Answer 11

To break up the large droplets of a lipid in an aqueous solution into smaller droplets

Question 12

What is the epidermis?

Answer 12

The layer of cells on the outer surface of a body or organ, such as a leaf

Question 13

What is faeces?

Answer 13

The undigested material that remains after digestion of food in humans

Question 14

What is fibre?

Answer 14

A plant material that is difficult to digest and keeps the food in the alimentary canal soft and bulky, aiding peristalsis.

Question 15

What is ingestion?

Answer 15

The taking of food into the alimentary canal

Question 16

What are microvilli?

Answer 16

Tiny finger-like extensions of the cell membrane of the surface cells of villi

Question 17

What are minerals (mineral ions)?

Answer 17

Nutrients that plants and animals need in small amounts, such as nitrates that are needed for making amino acids.

Question 18

What are palisade cells?

Answer 18

Cells in the upper part of a leaf that contain the most chloroplasts and carry out most of the photosynthesis

Question 19

What is physical digestion?

Answer 19

The breakdown of large food pieces, such as by chewing in the mouth

Question 20

What is secretion?

Answer 20

Releasing chemicals that have been made inside the cell into the fluid outside the cell

Question 21

What is spongy mesophyll?

Answer 21

The layer of cells in the lower part of the leaf where there are many air spaces, so increasing the internal surface area to volume ratio.

Question 22

What are stomata?

Answer 22

Tiny holes in the surface of a leaf (mostly the lower epidermis) which allow gases to diffuse in and out of the leaf.

Question 23

What are villus (villi)?

Answer 23

Finger-like projections of the small intestine wall where absorption of digested food molecules occur.

Question 24

What are vitamins?

Answer 24

Nutrients needed in tiny amounts to remain healthy, such as vitamins A, C and D

Question 25

What are waste products?

Answer 25

Products of a chemical reaction that are not needed, such as oxygen in photosynthesis