Topic 6 ( enzymes and digestive system )

Question 1

definition of enzymes

Answer 1

protein molecules that act as a biological catalyst.

Question 2

what does enzymes speed up

Answer 2

metabolic reactions

Question 3

definition of catalyst

Answer 3

a substance which increases the speed of a reaction, without being changed or used up in the reaction

Question 4

definition of substrate

Answer 4

a substance that an enzyme acts on to produce a chemical reaction

Question 5

definition of active site

Answer 5

A specific region of an enzyme where the substrate binds

Question 6

definition of enzyme - substrate - complex

Answer 6

The temporary complex formed when the substrate binds to the active site of the enzyme

Question 7

definition of product

Answer 7

a substance created in a chemical reaction

Question 8

explain how enzyme works

Answer 8

• substrate binds to the active site
• enzyme - substrate - complex
• substrate broken down into products

Question 9

how is the active site and substrate shaped

Answer 9

complementary in shape

Question 10

explain enzyme specificity

Answer 10

• enzyme speeds up 1 reaction
• enzyme specific to substrate
• lock - and - key hypothesis
• substrate fits in to the enzyme
• shape determined by amino acids

Question 11

what affects enzyme activity

Answer 11

• temperature
• pH levels

Question 12

how does temperature affect enzyme activity

Answer 12

• low temperature: less energy, less activity
• high temperature: more energy, increases rate of reaction

Question 13

definition of optimum temperature

Answer 13

the temperature which the enzyme work the fastest at

Question 14

optimum temperature for enzymes in humans

Answer 14

37 degrees

Question 15

definition of denaturation

Answer 15

when the shape of the active site changes shape and therefore enzyme can’t react with substrate

Question 16

how does high temperature denature an enzyme

Answer 16

• breaks the bond holding the enzyme together
• changes shape of active site

Question 17

how does pH levels affect enzyme activity

Answer 17

too high/low pH level denatures the enzyme

Question 18

what are the optimum pH levels for enzymes

Answer 18

different for enzymes

Question 19

how does pH levels denature enzymes

Answer 19

• moving too far away from optimum pH breaks the bond holding the enzyme together
• changes shape of active site

Question 20

which enzyme to use when investigating the affect of temperature on enzymes

Answer 20

amylase

Question 21

which enzyme to use when investigating the affect of pH levels on enzymes

Answer 21

amylase

Question 22

the order of the digestive system

Answer 22

Mouth (salivary glands)
Oesophagus
Stomach
Liver
Gall Bladder
Pancreas
Small intestine ( duodenum then illeum )
(appendix)
Large intestine
Rectum
Anus

Question 23

definition of ingestion

Answer 23

the taking in of substances

Question 24

definition of digestion

Answer 24

the breakdown of large, insoluble food molecules into small, soluble molecules using mechanical and chemical processes

Question 25

definition of absorption

Answer 25

the movement of small food molecules and ions through the wall of intestine to the blood

Question 26

definition of egestion

Answer 26

the passing out of food that has not been digested or absorbed as faeces through the anus

Question 27

function of the mouth

Answer 27

- where food enters - site of ingestion - mastication

Question 28

function of salivary glands

Answer 28

- site of chemical digestion - secrete saliva which contains amylase - lubricates the food

Question 29

function of oesophagus

Answer 29

- passes down food to the stomach through peristalsis - site of mechanical digestion

Question 30

definition of peristalsis

Answer 30

the process of wave-like muscle contractions that move food through the digestive system

Question 31

function of stomach

Answer 31

- churns food - produce pepsin - produce hydrochloric acid - site of chemical and mechanical digestion

Question 32

function of Liver

Answer 32

produces bile

Question 33

function of gall bladder

Answer 33

- stores bile - releases bile to the duodenum

Question 34

function of bile

Answer 34

- emulsifies fat molecules - neutralises stomach acid - set optimum pH level for enzymes

Question 35

function of pancreas

Answer 35

release pancreatic juice into duodenum ( contains amylase + protease + lipase )

Question 36

function of small intestine

Answer 36

- mix food with digestive enzymes - absorb food molecules into blood - site of absorption and chemical digestion

Question 37

function of duodenum

Answer 37

- start of small intestine - bile and pancreatic juice enters here

Question 38

function of Ileum

Answer 38

diffuse food molecules into the blood stream

Question 39

adaptions of the small intestine

Answer 39

- thin walls - long - villis - blood supply - permeable

Question 40

adaption of villi

Answer 40

- lacteal: transports fatty acid + glycerol away from small intestine - microvilli: small projection on the end of lining - blood capillaries: transports amino acids + glucose away from small intestine

Question 41

function of appendix

Answer 41

- where small intestine meets large intestine - stores healthy types of gut bacteria

Question 42

function of large intestine

Answer 42

absorbs excess water

Question 43

function of rectum

Answer 43

stores faeces until it's time to release

Question 44

function of anus

Answer 44

where faeces leave the body (alimentary canal)

Question 45

what are Carbohydrase

Answer 45

enzymes that breaks down carbohydrate (starch) into simple sugars

Question 46

features of Amylase

Answer 46

- type of carbohydrase - located in salivary glands, pancreas and small intestine - breaks down starch into maltose

Question 47

features of Maltase

Answer 47

- type of carbohydrase - located in salivary glands, pancreas and small intestine - breaks down maltose into glucose

Question 48

what are protease

Answer 48

- enzymes that breaks down protein into amino acids - produced in pancreas and small intestine

Question 49

features of pepsin

Answer 49

- type of protease - located in stomach - optimum pH level of 2 - breaks down protein into smaller polypeptide chains

Question 50

what are lipase

Answer 50

- enzymes that breaks down lipids into fatty acids and glycerol - produced in pancreas and small intestine