The human digestive system

Question 1

What are the three main nutrients?

Answer 1

Carbohydrates, proteins and fats.

Question 2

Why do humans require a digestive system?

Answer 2

Humans need aa digestive system to break down food into small soluble molecules to be absorbed into the blood. These digested food substances are then used by body cells to release energy through cellular respiration, for growth and tissue repair.

Question 3

Describe ingestion.

Answer 3

Ingestion is the taking in of food through the mouth.

Question 4

Describe digestion.

Answer 4

Digestion is the breaking down of large complex food into small soluble molecules which can be easily absorbed into the bloodstream. Physical-Large pieces of food are separated into smaller pieces. It increases surface area to volume ratio for faster rate of chemical digestion by enzymes.
Chemical- Complex nutrient molecules are broken down into simpler, soluble molecules that can be easily absorbed. This requires the action of digestive enzymes.

Question 5

Describe absorption.

Answer 5

nd products of digestion are absorbed into the bloodstream by diffusion and transported to body cells.

Question 6

Describe assimilation.

Answer 6

absorbed food substances are used to make new cells, release energy, or stored.

Question 7

Describe egestion.

Answer 7

undigested and unabsorbed food substances are passed out of the body as faeces.

Question 8

Define enzymes.

Answer 8

Enzymes are biological molecules produced to speed up chemical reactions that occur within the body.

Question 9

What is the enzyme that digests carbohydrates?

Answer 9

Carbohydrase or amylase

Question 10

What is the enzyme that digests proteins?

Answer 10

Protease

Question 11

What is the enzyme that digests fats?

Answer 11

Lipase

Question 12

What are the end products of carbohydrates?

Answer 12

Glucose or simple sugars

Question 13

What are the end products of proteins?

Answer 13

amino acids

Question 14

What are the end products of fats?

Answer 14

glycerol and fatty acids

Question 15

What is the function of stomach?

Answer 15

Churning of food into smaller pieces increases surface area to volume ratio and allows faster rate of chemical digestion by protease. Gastric juice secreted contains proteases to digest proteins into polypeptides. Gastric juice also contains hydrochloric acid which kills harmful microorganisms and provides optimum PH for protease to function

Question 16

What is the function of liver?

Answer 16

Liver produces bile. Bile is temporarily stored into gall bladder and released into small intestine

Question 17

What is the function of pancreas?

Answer 17

Secrete pancreatic juice which contains enzymes that aid in digestion.

Question 18

What is the function of small intestine?

Answer 18

The emulsification of fats by bile occurs. The bile breaks up fats into smaller droplets, increasing surface area to volume ratio for faster rate of chemical digestion by lipase. Intestinal juice and pancreatic juice which carbohydrase, protease and lipase are secreted in the small intestine to digest all carbohydrates, proteins and fats. End products of digestion are absorbed into the bloodstream across intestinal walls.

Question 19

What is the function of large intestine?

Answer 19

Remaining water and mineral salts are absorbed here.

Question 20

Describe constipation.

Answer 20

Faeces moves through large intestine very slowly thus too much water is absorbed making it hard and dry.

Question 21

Describe gastric pain.

Answer 21

commonly caused by gastritis, painful swelling of the stomach lining.

Question 22

Describe food poisoning.

Answer 22

Stomach cramps, vomiting and diarrhea to get rid of harmful bacteria.

Question 23

What are the causes of constipation?

Answer 23

The causes of constipation are stress, consumption of certain medicine and insufficient water and fibre in the diet.

Question 24

What are the causes of gastric pain?

Answer 24

Bacterial or viral infection.

Question 25

Eating food contaminated by harmful bacteria.

Question 26

What are ways to prevent constipation?

Answer 26

Eating high fibre food, drinking more water and exercising.

Question 27

What are ways to prevent gastric pain?

Answer 27

Eating meals regularly, avoiding caffeine and alcohol, and avoid too much oily foods

Question 28

What is the function of carbohydrates?

Answer 28

Immediate source of energy.

Question 29

What is the function of proteins?

Answer 29

make new cells for growth and repair.

Question 30

What is the function of fats?

Answer 30

insulation preventing our bodies from losing too much heat.