Chapter 3

Question 1

explain tissue

Answer 1

a tissue is a group of cells with similar structure and function

Question 2

explain organs

Answer 2

organs are collections of tissues performing specific functions

Question 3

explain organ systems

Answer 3

organs are organised into organ systems which work together to form organisms

Question 4

what is the digestive system

Answer 4

is an organ system where several organs work together to digest and absorb food

Question 5

all the organs in the digestive system (14)

Answer 5

mouth, gullet, diaphragm, stomach, liver, pancreas, gall bladder, duodenum, bile duct, small intestine, appendix, anus, rectum, large intestine

Question 6

what are carbohydrates

Answer 6

carbohydrates are made up of units of sugar

Question 7

what are lipids

Answer 7

lipids consist of three molecules of fatty acids bonded to a molecule of glycerol

Question 8

what are protein molecules

Answer 8

protein molecules are made up of long chains of amino acids

Question 9

what are simple sugars

Answer 9

simple sugars are carbohydrates that contain only one or two sugar units

Question 10

explain catalysts

Answer 10

catalysts increase the rate of chemical reactions without changing chemically themselves

Question 11

explain enzymes

Answer 11

enzymes are biological catalysts and catalyse specific reactions in living organisms due to the shape of their active site.

Question 12

what are enzymes

Answer 12

enzymes are proteins. the amino acids chains are folded to form the active site, which matches the shape of a specific substrate molecule.

Question 13

what is metabolism

Answer 13

is the sum of all the reactions in a cell or the body

Question 14

what is enzyme activity affected by (2)

Answer 14

temperature and pH

Question 15

what happens to the enzyme in the high temperature

Answer 15

denatures the enzyme, changing the shape of the active site

Question 16

explain: digestion

Answer 16

digestion involves the breakdown of large insoluble molecules into soluble substances that can be absorbed into the blood across the wall of the small intestine

Question 17

where are digestive enzymes produced

Answer 17

they are produced by specialised cells inn glands and in the lining of the digestive system.

Question 18

carbohydrates are broken down by

Answer 18

carbohydrase

Question 19

proteins are broken down by

Answer 19

proteases

Question 20

lipids are broken by

Answer 20

lipases

Question 21

in what conditions do protease enzymes work

Answer 21

acid conditions. stomach produces hydrochloric acid which maintains a low pH

Question 22

where is bile stored

Answer 22

liver

Question 23

what does bile do

Answer 23

neutralises acid and emulsifies fat