organisation in animals 2

Question 1

what is an enzyme

Answer 1

protein molecule that acts as catalysts, speeding up chemical reactions without getting used up

Question 2

what is a denatured enzyme

Answer 2

an enzyme where the active site has changed shape and the substrate will no longer fit

Question 3

why are enzymes specific

Answer 3

only certain substrate will fit into the active site of each enzyme - LOCK N KEY THEORY

Question 4

describe the enzyme action

Answer 4

substrate moves toward the site of the enzymes

the substrate collides with the active site

the products have collided and a substrate molecule was broken

Question 5

how can enzymes be denatured

Answer 5

they can be denatured by:
- high temperatures
- low/high pH

Question 6

what is optimum temperature/pH

Answer 6

the temperature/pH value an enzyme works best at

most enzymes have the same optimum temperature of 37 degrees C

there are a range of different optimum pH values depending on the enzyme function

Question 7

3 important enzymes

Answer 7

pepsin - found in the stomach and helps digestion of protein

salivary amylase - helps digestion of carbohydrates

alkaline phosphatase - found in the bloodstream and helps in the breakdown of protein

Question 8

enzyme temperature denature

Answer 8

at low temperatures , enzymes and substrates don’t have much energy
- collision don’t happen often
- rate of reaction is low (not 0)

as the temperature increases, the rate of collision increases
- more reactions will occur
- rate of reaction increases

after the optimum temperature, the enzyme molecules begin to denature so the rate of reaction decreases

Question 9

enzyme pH denature

Answer 9

at pH levels too low below optimum pH
- enzyme is denatured
- rate of reaction is 0

each enzyme has an optimum pH where it works best

at pH levels too far above the optimum pH
- enzyme is denatured
- rate of reaction is 0

Question 10

how do you measure rate of reaction in enzymes

Answer 10

rate of reaction - speed at which something occurs

for when ALL of something has happened:

1/time OR 1000/time

for when PART of something has happened:

change/time

Question 11

lipase - substrate, products, production site, reaction site

Answer 11

substrate:
lipids

products:
fatty acids/glycerol

sites of production:
pancreas/small intestine

site of reaction:
small intestine

Question 12

protease - substrate, products, production site, reaction site

Answer 12

substrate:
proteins

products:
amino acids

sites of production:
stomach/pancreas/small intestine

site of reaction:
stomach/small intestine

Question 13

amylase - substrate, products, production site, reaction site

Answer 13

substrate:
starch

products:
sugars

sites of production:
salivary glands/pancreas/small intestine

site of reaction: mouth/small intestine

Question 14

health definition

Answer 14

state of physical and mental wellbeing

Question 15

disease definition

Answer 15

something responsible for causing ill health which is not an injury

Question 16

non-communicable disease

Answer 16

a disease that cannot be passed from person to person

Question 17

misconception around risk factors

Answer 17

exposure to risk factors doesn’t mean that someone is definitely going to develop a condition
e.g. clear link between smoking and lung cancer however not every smoker is going to get lung cancer

Question 18

coronary arteries

Answer 18

cardiac muscles require energy to constantly contract
the heart is surrounded by a network of arteries - coronary arteries
they supply muscles of the heart with lots of oxygen and glucose to respire efficiently

Question 19

statins
advantages!
disadvantages.

Answer 19

drugs that lower the amount of bad cholesterol in your blood
–> cholesterol is a required fatty acid but too much bad cholesterol causes build up in blood vessels and coronary heart disease

• reduces heart attack risk!
• has beneficial effects on other causes!
• not suitable for people with liver disease.
• side effects.
• taken for life.
• cannot take whilst pregnant/breastfeeding.

Question 20

heart transplant
advantages!
disadvantages.

Answer 20

a heart too damaged or diseased to be repaired can be replaced with a healthy heart from a donor

• improves life quality significantly!
• only a few donor hearts.
• long recovery time.
• risk of rejection from immune system.

Question 21

valve replacement
advantages!
disadvantages.

Answer 21

heart valves too diseased or damaged means they either don’t open properly (stenosis) or don’t close properly (regurgitation) which can stop your heart from working as it should.
faulty valves can be replaced by a mechanical or biological valve (from an animal)

• restores blood flow through the heart!
• biological valves may wear out.
• blood clots could stick to mechanical valves so anti
  blood-clot tablets would need to be taken
• major operation

Question 22

stents
advantages!
disadvantages.

Answer 22

a stent is a small metal, mesh tube inserted into a blocked/collapsed coronary artery to reopen it and allow blood to flow through

• very effective!
• widens coronary arteries that haven’t responded to treatment!
• short recovery time!
• in a minority of cases, further treatment is required.

Question 23

artificial hearts

Answer 23

if a patient is awaiting heart transplant or cannot wait for a donor any longer, they may be given an artificial heart

however they have to carry the heart mechanism with them in a bag

Question 24

what is apoptosis

Answer 24

process of regulated cell death

Question 25

what happens when cells divide too quickly

Answer 25

cell division and death is controlled by a series of chemical signalling and checkpoints in the cell cycle.
if something goes wrong with the cell - mutation - it may start to divide too quickly
–> uncontrolled cell division can lead to a tumour

Question 26

name for cancer risk factors

Answer 26

carcinogens

Question 27

types of tumour

Answer 27

benign
malignant

Question 28

explain a benign tumour

Answer 28

• contained within a capsule
• cannot invade surrounding tissues
• are not cancerous
• may be harmful

Question 29

explain a malignant tumour

Answer 29

• not contained within a capsule
• can invade surrounding tissues
• can form secondary tumours (metastasis)

Question 30

explain metastasis

Answer 30

cancerous tumours can form secondary tumours

some cancerous cells can break off from the original tumour, travel in the blood and form new tumours elsewhere in the body

Question 31

name and describe two treatments of cancer

Answer 31

radiotherapy - use of high power ionising radiation to destroy cancerous cells

chemotherapy - use of drugs to destroy cancerous cells

both highly effective however it can lead to nasty side effects, it’s not well targeted and doesn’t always work