Animal tissues, Organs and Organ systems

Question 1

amylase - where is it released and what does it break down.

Answer 1

released - salivary glands and pancreas

breaks down - carbohydrates into simple sugars

Question 2

protease - where is it released and what does it break down.

Answer 2

released - stomach and pancreas

breaks down - proteins into amino acids

Question 3

lipase - where is it released and what does it break down.

Answer 3

released - pancreas

breaks down - lipids into fatty acids and glycerol

Question 4

define digestion

Answer 4

where large insoluble molecules are broken down into smaller soluble ones that can be absorbed into the bloodstream.

Question 5

explain the “lock and key theory”

Answer 5

enzymes are made of proteins and biological catalysts - substances that increase the rate of chemical reactions without being used up.

the shape of the active site of the enzyme is specific for each substrate.

Question 6

describe how changes in temperature will affect enzyme reactions.

Answer 6

increasing the temperature will increase the rate of reaction due to increased collisions between the enzyme and the substrate.

but if the temperature is too high, the enzymes will denature.

Question 7

describe how Ph affects enzyme reactions.

Answer 7

the stomach releases acids.
the enzymes produced in the stomach work best in acidic conditions.

the enzymes produces in the small intestine and pancreas work best in alkaline conditions.

Question 8

describe the role of bile.

Answer 8

bile is made in the liver and stored in the gall bladder.
it is alkaline to neutralise the hydrochloric acid from the stomach

it also emulsifies fat to form small droplets which increases the surface area.

the alkaline conditions and large surface area increase the rate of fat breakdown by lipase.

Question 9

describe the role of the heart.

Answer 9

the heart is an organ that pumps blood around the body in a double circulatory system.

the right ventricle pumps blood to the lungs where gas exchange takes place.
the left ventricle pumps blood around the rest of the body.

Question 10

describe the structure of the arteries.

Answer 10

carries blood away from the heart
thick muscular walls
small lumen
carries blood under high blood pressure

Question 11

describe the structure of the veins.

Answer 11

carries blood to the heart
thin walls
large lumen
have valves
carries blood under low blood pressure

Question 12

describe the structure of the capillaries.

Answer 12

connects arteries and veins
one cell thick
carries blood under very low blood pressure

Question 13

describe the process of gas exchange in the lungs.

Answer 13

the heart pumps low oxygen containing blood to the lungs.

in the lungs, the oxygen and carbon-dioxide are exchanged in the alveoli at the end of the bronchial tubes.

the alveoli are surrounded by capillaries.

Question 14

state and describe the components in blood.

Answer 14

plasma - pale yellow fluid, transports cells, carbon-dioxide and waste.

red blood cells - have no nucleus, contain haemoglobin which carries oxygen, large surface area to volume ratio.

white blood cells - some produce antibodies and others surround and engulf foreign cells.

platelets - clump together to help form clots, protect the body by stopping/reducing bleeding.

Question 15

state what happens in someone who has CHD

Answer 15

layers of fatty material build up inside the coronary arteries, narrowing them.

this reduces the flow of blood through coronary arteries, resulting in a lack of oxygen for the heart muscle.

Question 16

state and describe the risk factors for CHD.

Answer 16

smoking and high blood pressure - damages the lining of the artery, leading to a build up of fatty deposits.

high cholesterol - cholesterol is a fatty substance that is carried in the blood by proteins

not enough exercise - increases blood pressure and cholesterol in the blood.

Question 17

describe how stents can be used to treat CHD.

Answer 17

stents are metal cylinder grids which can be inserted into an artery to maintain blood flow by keeping the artery open so that the heart continues to receive enough oxygen to function effectively.

Question 18

describe how statins can be used to treat CHD.

Answer 18

statins are drugs that lower harmful cholesterol in the blood and stop the liver producing too much cholesterol and reduce the rate at which it is deposited.

Question 19

describe the role of heart valves

Answer 19

they prevent the blood in the heart from flowing in the wrong direction.

in some people, the heart valves may become faulty, preventing the valves from opening fully or the heart valve may develop a leak because it does not close fully.

Question 20

describe how different diseases may interact.

Answer 20

defects in the immune system - this means that an individual is more likely to suffer from infectious diseases.

viruses living in cells can be the trigger for cancers to form.

severe physical ill health can lead to depression and other mental illness

Question 21

state the human and financial costs of non-communicable diseases.

Answer 21

human costs:
lower quality of life
shorter lifespan
families are also affected

financial costs:
cost of healthcare
reduced income due to inability to work
adaptions to specialist equipment

Question 22

describe risk factors that may cause cardiovascular disease.

Answer 22

diet - a diet high in saturated fats can increase the levels of LDL

smoking - tobacco smoke damages the lining of the arteries, the carbon-monoxide reduces the amount of oxygen in the blood so the heart has to pump harder

lack of exercise - exercising regularly lowers blood pressure and stress.

Question 23

describe risk factors for type 2 diabetes.

Answer 23

obesity:
type two diabetes is where the cells in the body are less sensitive or resistant to insulin so the body cannot control the concentration of glucose in the blood correctly.

obesity increases the risk of developing type 2 diabetes because you have more fat around your abdomen.

Question 24

describe risk factors for liver disease and brain damage.

Answer 24

alcohol:
the liver breaks down toxins in alcohol so if you have too much alcohol, the first stage of the liver disease is when the liver becomes too fatty.

alcohol affects the way the nerve cells in the brain work and the cells then become damaged. The brain mass may also shrink.

Question 25

describe the risk factors for lung disease.

Answer 25

smoking:

COPD narrows the airways and makes it difficult to get rid of carbon-dioxide and get in oxygen needed for respiration.

Question 26

describe benign tumours

Answer 26

growth of abnormal cells
contained in one area
usually within a membrane surrounding the cells
they do not invade other parts of the body

Question 27

describe malignant tumours

Answer 27

growths of abnormal cells
these are cancerous
invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours
can be caused by lifestyle or genes