Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CIE IGCSE Biology > Chapter 7 - Human nutrition > Flashcards

Chapter 7 - Human nutrition Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is a balanced diet?

A

A balanced diet consists of all the food groups in the correct proportions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of carbohydrates?

A

Source of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are some sources of carbohydrates?

A

Breads, cereals, pasta, rice, potatoes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of proteins?

A

Growth and repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some sources of proteins?

A

Meat, fish, eggs, pulses, nuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of lipids?

A

Insulation and energy storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some sources of lipids?

A

Butter, oil, nuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of dietary fibre?

A

Provides bulk (roughage) for the intestine to push food through it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some sources of dietary fibres?

A

Vegetables, whole grains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the function of vitamin C?

A

Forms an essential part of collagen protein which makes up skin, hair, gums and bones. Deficiency causes scurvy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some sources of vitamin C?

A

Citrus fruit, strawberries, green vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of vitamin D?

A

Helps the body to absorb calcium and so required for strong bones and teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are some sources of vitamin D?

A

Oily fish, eggs, liver, dairy products, also made naturally by the body in sunlight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of calcium?

A

Needed for strong teeth and bones and involved in the clotting of blood. Deficiency can lead to osteoporosis later in life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some sources of calcium?

A

Milk, cheese, eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of iron?

A

Needed to make haemoglobin, the pigment in red blood cells that transports oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some sources of iron?

A

Red meat, liver, leafy green vegetables like spinach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the function of water?

A

Needed for chemical reactions to take place in cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are some sources of water?

A

Water, juice, milk, fruits, vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is scurvy?

A

Scurvy is caused by a severe deficiency in vitamin C. Its symptoms include anaemia, exhaustion, spontaneous bleeding, pain in the limbs, swelling, gum ulcerations, tooth loss. Scurvy can be treated with oral or intravenous vitamin C supplements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is rickets?

A

Rickets is caused by a severe lack of vitamin D. Its symptoms include bone pain, lack of bone growth and soft or weak bones. It can be treated by consuming foods containing calcium and vitamin D or using vitamin D supplements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the path of the digestive system?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is ingestion?

A

Ingestion is the food or drink that is taken into the body through the mouth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is mechanical digestion?

A

Mechanical digestion is when food is broken down into smaller pieces without chemical change to the food molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is chemical digestion?

A

Chemical digestion is when large, insoluble molecules are broken down into small, soluble molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is absorption?

A

Absorption is when small food molecules and ions move through the wall of the intestine into the blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is assimilation?

A

Assimilation is the uptake and use of nutrients by cells.

28
Q

What is egestion?

A

Egestion is the removal of undigested food from the body as faeces.

29
Q

What is the function of the mouth during digestion?

A

Food is ingested here, and the teeth break it down into smaller pieces during mechanical digestion.

30
Q

What is the function of the salivary glands during digestion?

A

Saliva is secreted into the mouth. The enzyme amylase in saliva begins to digest starch into maltose. Saliva lubricates the food for easy swallowing.

31
Q

What is the function of the oesophagus during digestion?

A

This tube connects the mouth to the stomach. Contractions of the walls of the oesophagus force the food downwards; this is called peristalsis.

32
Q

What is the function of the stomach during digestion?

A

Churning of the muscular stomach walls continues the process of mechanical digestion. Protease enzymes begin protein digestion. Hydrochloric acid provides a suitable pH for the enzymes and also destroys any pathogens in food.

33
Q

What is the function of the liver during digestion?

A

Bile is produced here. Biles aids the digestion of fats, as well as neutralising stomach acid as it exits the stomach.

34
Q

What is the function of the gall bladder during digestion?

A

Bile is stored here before being released into the duodenum via the bile duct.

35
Q

What is the function of the pancreas during digestion?

A

Amylase, protease and lipase enzymes are produced here before being released into the duodenum.

36
Q

What is the function of the duodenum (small intestine) during digestion?

A

Food enters the small intestine from the stomach here. The acidic stomach contents are neutralised by the bile and become slightly alkaline. Enzymes complete chemical digestion here.

37
Q

What is the function of the ileum (small intestine) during digestion?

A

Food and water are absorbed into the blood via villi in the lining of the ileum

38
Q

What is the function of the colon (large intestine) during digestion?

A

Remaining water is absorbed from food into the blood and the solid waste left behind in the colon forms faeces.

39
Q

What is the function of the rectum (large intestine) during digestion?

A

Faeces are stored here prior to egestion.

40
Q

What is the function of the anus (large intestine) during digestion?

A

Faeces leave the body via the anus; this is egestion.

41
Q

What is physical digestion?

A

Physical digestion is the breakdown of food molecules into smaller pieces without chemical change to the food molecules. Physical digestion increase the surface area of food for the action of enzymes in chemical digestion. It is mainly carried out by the chewing of teeth, the churning of the stomach and the emulsification of fates by bile in the duodenum.

42
Q

What are teeth?

A

Teeth are held firmly in the bone of the jaw. They are used for chewing to increase the surface area of the food so that it can be exposed to saliva and other digestive juices and broken down more quickly. Teeth are embedded in bone and the gums. The four types of teeth are incisors, canines, premolars and molars.

43
Q

What are incisors?

A

Incisors are chisel shapers and are used for biting and cutting.

44
Q

What are canines?

A

Canines are pointed shaped for tearing, holding and biting.

45
Q

What are premolars and molars?

A

Premolars and molars are larger, flat surfaces with ridges at the edges for chewing and grinding up food.

46
Q

Diagram of teeth structure

A
47
Q

What is enamel?

A

Enamel is the hardest substance in the body. This covers the tooth and provides a tough surface for biting and chewing.

48
Q

What is dentine?

A

Dentine is also a hard substance. It has tiny tubes running from the pulp cavity outwards which are filled with blood vessels and nerves. The tooth is a living part of the body and needs blood vessels to supply it with nutrients. The nerve senses pressure and pain.

49
Q

What is pulp cavity?

A

Pulp cavity is the hollow region inside the tooth. Pulp is the blood vessels and nerves which keep the tooth alive.

50
Q

What is cement?

A

Cement covers the dentine in the jaw and provides anchorage for tough fibres.

51
Q

What is the stomach?

A

The stomach lining contains muscles which contract to physical squeeze and mix the food with strong digestive juices that are present. This is known as the stomach churning.

52
Q

Where is bile produced?

A

Cells in the liver produce bile which is then stored in the gallbladder.

53
Q

What is bile?

A

Bile is alkaline to neutralise the hydrochloric acid which comes from the stomach to allow the enzymes in the small intestine which have a higher pH to work at their optimum. It also breaks down large drops of fat into smaller ones by emulsification. The larger surface area allows lipase to chemically breakdown the lipid into glycerol and fatty acids faster.

54
Q

What is chemical digestion?

A

Chemical digestion is the breakdown of large insoluble molecules into small soluble molecules. The role of chemical digestion is producing small soluble molecules that can be absorbed.

55
Q

What is amylase?

A

Amylases are produced in the mouth and the pancreas and secreted into the duodenum. Amylases digest starch into smaller sugars. Amylase is secreted into the alimentary canal in the mouth and the duodenum from the pancreas and digests starch into maltose which is a disaccharide. Maltose is digested by the enzyme maltase into glucose on the membranes of the epithelium lining of the small intestine.

56
Q

What is protease?

A

Proteases are a group of enzymes that break proteins down into amino acids in the stomach and small intestine. The enzymes in the small intestine having been produced in the pancreas. The two types of proteases are pepsin and trypsin.

57
Q

What is pepsin?

A

Pepsin is produced in the stomach and breaks down protein in acidic conditions.

58
Q

What is trypsin?

A

Trypsin is produced in the pancreas and secreted into the duodenum where it breaks down protein in alkaline conditions.

59
Q

What is lipase?

A

Lipase enzymes are produced in the pancreas and secreted into the duodenum. They digest lipids into fatty acids and glycerol.

60
Q

What is hydrochloric acid?

A

Hydrochloric acid kills bacteria in food and gives an acidic pH for enzymes to work in the stomach. The low pH kills bacteria in food that we have ingested as it denatures the enzymes in their cells meaning they cannot carry out any cell reactions to maintain life. Pepsin, which is produced in the stomach, is an example of an enzyme which has a very low optimum pH around pH 2, so the hydrochloric acid ensures that conditions in the stomach remain within the optimum range for pepsin to work at its fastest rate.

61
Q

What is bile?

A

Bile is an alkaline mixture that neutralizes the acidic mixture of food and gastric juices entering the duodenum from the stomach, uses emulsification to break down large drops of fats into smaller ones and it provides a suitable pH for enzyme action.

62
Q

What is absorption?

A

Absorption is the movement of digested food molecules from the digestive system into the blood (glucose and amino acids) and lymph (fatty acids and glycerol). Nutrients are absorbed in the small intestine.

63
Q

Where is water absorbed?

A

Water is absorbed in both the small intestine and the colon but most absorption of water (around 80%) happens in the small intestine.

64
Q

How is the ileum adapted for absorption?

A

The ileum is adapted for absorption as it is very long and has highly folded surface with millions of villi. These adaptations increase the surface area of the ileum, allowing absorption to take place faster and more efficiently.

65
Q

What are villi?

A

Villi are tiny, finger life projections.

66
Q

How do villi increase absorption?

A

Microvilli on the surface of the villus further increases the surface area for faster absorption of nutrients. Wall of the villus is one cell thick meaning that there is only a short distance for absorption to happen by diffusion and active transport. Well supplied with a network of blood capillaries that transport glucose and amino acids away from the small intestine in the blood. Lacteal runs though the centre of the villus to transport fatty acids and glycerol away from the small intestine in the lymph.

CIE IGCSE Biology (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions