B2

Question 1

discuss the differences between a bengin and malignant tumour

Answer 1

a benign tumour is the growth of cells contained in one place, usually within a membrane. it isn’t cancerous and grows until there is no more room. it doesn’t invade other tissues and if it causes pressure or damage to an organ it can be dangerous.

malignant tumour is cancerous, the tumor grows and spreads to other tissues. the tumour may split up, resulting in cells being carried in the bloodstream or lymphatic system. they can travel to and stay in another organ, potentially causing secondary tumours. the cancer cells divide more rapidly and have a longer life span in comparison to normal cells.

Question 2

what is cancer

Answer 2

uncontrolled growth and division of the cells

Question 3

what does the Benedict’s test, test for

Answer 3

sugar

Question 4

what is a positive result for the Benedict test

Answer 4

brick red colour

Question 5

what does the Iodine’s test, test for

Answer 5

starch

Question 6

what is a positive result for the Iodine test

Answer 6

blue-black colour

Question 7

what does the Biuret’s test, test for

Answer 7

proteins

Question 8

what is a positive result for the Biuret test

Answer 8

purple colour

Question 9

what is a positive result for the Emulsion test

Answer 9

when ethanol is added, there is a cloudy layer if a lipid is present

Question 10

what does the Emulsion test, test for

Answer 10

lipids

Question 11

what does the Sudan III test for

Answer 11

lipids

Question 12

what is a positive result for the Sudan III test

Answer 12

red layer forms on top

Question 13

where is bile produced in

Answer 13

liver

Question 14

where is bile stored in

Answer 14

gallbladder

Question 15

what are the two roles of bile

Answer 15

• neutralise the HCL which comes from the stomach
• emulsifies large drops of fat into smaller ones

Question 16

rate of reaction =

Answer 16

change/time

Question 17

what organs is the digestive system made out of

Answer 17

glands (salivary and pancreas), stomach, small and large intestine, liver

Question 18

what are enzymes

Answer 18

BIOLOGICAL catalysts

Question 19

What does the Lock and Key Hypothesis state

Answer 19

the shape of the active site matches the shape of its substrate molecules

Question 20

if an enzyme is denatured by temperature (37 degrees) or pH can it go back to its original shape

Answer 20

only for pH (7)

Question 21

where is carbohydrase produced

Answer 21

small intestine, pancreas, glands

Question 22

where is protease produced

Answer 22

stomach but other forms can be found in pancreas and small intestine

Question 23

where is lipase produced

Answer 23

pancreas and small intestine

Question 24

True or Flase? A tissue is a group of cells of only one type which work together to perform a function

Answer 24

FALSE. A tissue doesn’t have to be made up of only one cell type, it can include more than one type of cell

Question 25

what is the role of the epithelial tissue

Answer 25

they line the tissue of organs

Question 26

explain how the change in blood flow to the athlete's muscles helps him to run

Answer 26

blood flow increases wen the runner is running. this results in more oxygen and glucose supplied to the runner (for more respiration therefore releasing more energy for muscle contraction) () is where marks were lost

Question 27

explain how the change in blood flow to the athlete's muscles helps him to run

Answer 27

blood flow increases wen the runner is running. this reults in more oxygen and glucose supplied to the runner (for more respiration therefore releasing more energy for muscle contraction) () is where marks were lost

Question 28

some people who take beta blockers get out of breath when they exercise [ao3]. suggest why they can have this effect.

Answer 28

when we exercise, we respire more and release more energy therefore we need more oxygen. beta blockers reduce heart rate during exercise. they reduce stroke volume therefore it reduces cardiac output and therefore the heart cannot supply oxygen fast enough. therefore, the breathing rate increases to increase the rate of oxygen absorbed and remove the co2 from the body. however, the increased breathing rate cannot keep up with the changes in the heart function. so those who take beta blockers get out of breath when they exercise because it lowers the heart rate

Question 29

what is the active site of an enzyme

Answer 29

the active site is part of the enzyme that the substrate fits into

Question 30

how is a tumour formed

Answer 30

it happens when the cell cycle sequence is lost and cells grow in an abnormal, uncontrolled way

Question 31

a person with CF has cells that line the lungs and digestive system create too much mucus. this blocks the duct leading from the pancreas to the small intestines. it also blocks the tubes leading to the alveoli in the lungs. explain why children with CF grow more slowly than those without.

Answer 31

fewer enzymes enter small intestine so enzymes break down/digest less food thus less absorption of nutrients. this means that less glucose can enter the bloodstream and so less glucose is available for respiration. in addition the fewer absorption means less amino acids can enter so less protein is made for growth. less oxygen enters the bloodstream so less oxygen is available for respiration thus less energy is released and available for growth.

Question 32

describe how increased heart rate, increased breathing rate and increased blood glucose concentration would improve athletic performance

Answer 32

the increased heart rate increases cardiac output and oxygen pumped out. the increased breathing rate increases the rate of oxygen that is provided to the cells and the carbon dioxide removed. the increase in glucose concentration provides more glucose and thus more energy for muscle contraction. it also means respiration can occur faster

Question 33

explain why a transplanted organ may be rejected.

Answer 33

the transplanted organ may not be recognised by your body's immune system which will result in your immune system producing antibodies to attack the antigens on the transplanted organ

Question 34

explains how the amylase breaks down starch. answer in terms of the lock and key theory.

Answer 34

the lock and key theory state that the site of the enzyme's active site will fit the site of the substrate and only that substrate. the amylase's active site is complementary to the starch. this allows amylase to break the starch down into smaller molecules