Human Nutrition

Question 1

Nutrition definition

Answer 1

The process by which organisms obtain and use food

Question 2

Autotroph

Answer 2

Make their own food by photosynthesis
Eg: plants

Question 3

Heterotroph

Answer 3

Can’t make own food, eat other plants or animals
Eg: humans

Question 4

Herbivores

Answer 4

Eat plant material only
Eg: rabbit

Question 5

Carnivores

Answer 5

Eat other animals
Eg: foxes, lions

Question 6

Omnivores

Answer 6

Eat both plants and animals
Eg: humans and badgers

Question 7

Functions of food

Answer 7

Make new cells
Replace old cells
Repair cells
Defend ourselves
Help in reproduction

Question 8

Digestion

Answer 8

Is the chemical and physical breakdown of food into soluble form, it’s necessary for transport and absorption of digested food

Question 9

Stages in human digestion

Answer 9

Ingestion
Digestion
Absorption
Assimilation
Egestion

Question 10

1. Ingestion

Answer 10

Taking in of food into the mouth

Question 11

2. Digestion

Answer 11

The mechanical and chemical breakdown of food into soluble form

Question 12

3. Absorption

Answer 12

The passage of the products of digestion into the blood or lymph

Question 13

4. Assimilation

Answer 13

The cell uses food (eg:) protein is used for growth and repair of cells

Question 14

5. Egestion

Answer 14

Removal of the undigested and unabsorbed material from the body

Question 15

The mouth - physical digestion

Answer 15

Physical digestion in mouth is carried out by the teeth

Question 16

Human Dental formula

Answer 16

2( i2/2, c1/1, pm2/2, m3/3)

Question 17

Incisors

Answer 17

Used for cutting and biting

Question 18

Canines

Answer 18

For tearing

Question 19

Premolars

Answer 19

Crushing and grinding

Question 20

Molars

Answer 20

Crushing and grinding

Question 21

How many teeth in adults?

Answer 21

32

Question 22

The mouth - chemical digestion

Answer 22

Carried out by the enzyme amylase — produced by salivary glands

Question 23

pH of mouth

Answer 23

7-8

Question 24

Amylase optimum pH

Answer 24

7-8

Question 25

Amylase digests..

Answer 25

Starch into maltose

Question 26

The Oesophagus

Answer 26

Is made of involuntary muscle, regular contractions push food along the guy This is called peristalsis

Question 27

Peristalsis definition

Answer 27

The alternate contraction and relaxation of the muscles of the gut wall

Question 28

What stimulates peristalsis

Answer 28

Fibre

Question 29

Lack of fibre effect:

Answer 29

Constipation

Question 30

The stomach definition

Answer 30

A muscular bag which food remains for 2-4 hours. The wall of the stomach has gastric glands which produce HCL, enzymes and mucous.

Question 31

What do gastric glands produce

Answer 31

HCL Mucus Enzymes

Question 32

pH of stomach

Answer 32

2

Question 33

The stomach - physical digestion

Answer 33

Occurs when stomach churns the food This turns food into a liquid called chyme

Question 34

The stomach - chemical digestion

Answer 34

Occurs due to the presence of protease enzymes. The inactive enzyme pepsinogen is activated by HCL in the stomach to form Pepsin. Pepsin digests protein into peptides

Question 35

HCL function

Answer 35

Kills bacteria and other micro organisms that may’ve been ingested with the food

Question 36

Why is the stomach not digested by pepsin of hcl?

Answer 36

Because of the protective mucous lining

Question 37

The small intestine The Duodenum

Answer 37

C shaped structure Digestion occurs here

Question 38

The duodenum what happens

Answer 38

Digestion occurs here Liver produces Bile (sodium hydrogen carbonate, which neutralises pH and emulsifies fats) Pancreas produces amylase and lipase

Question 39

The ileum What happens here

Answer 39

Absorption of nutrients into blood

Question 40

Adaptions of ileum

Answer 40

Millions of villi increased surface are for absorption of materials Micro villi present Large blood supply Only one cell thick

Question 41

Lácteas function

Answer 41

Absorbs fats, fats are transported in lymphatic system, enter blood stream at subclavian gland

Question 42

End products of digestion

Answer 42

Starch + amylase > maltose (hepatic vein) Lipids + lipase > glycerol and fatty acids (lacteal) Pepsinogen > pepsin + protein > amino acids (hepatic vein)

Question 43

Movement of materials by

Answer 43

Diffusion or passive transport

Question 44

Amino acids and deamination

Answer 44

Are toxic to the body the liver breaks them down into urea this is called deanination and urea goes to kidney to make urine

Question 45

Excess carbohydrates

Answer 45

Are converted to glycogen and stored in liver

Question 46

Pancreas function

Answer 46

Produces hormone insulin and a range of digestive enzymes such as amylase and lipase

Question 47

Bile function

Answer 47

Formed by breakdown of red blood cells Composed of water bile salts and pigments Made in liver stored in gall bladder Used to emulsify fats and neutralise acid from stomach (sodium hydrogen carbonate)

Question 48

Functions of liver

Answer 48

Breaks down poisons Breaks down old red blood cells Makes bile Neutralises chyme

Question 49

Large intestine function

Answer 49

Reabsorb water and make b and k vitamins

Question 50

Symbiotic bacteria in large intestine

Answer 50

Vitamin B and K Break down cellulose