Biology Paper 1 - Animal Tissues, Organs And Organ Systems

Question 1

‘Lock And Key’ Theory

Answer 1

The substrate binds on to the active site of the enzyme, they fit complementary to each other. Almost like a Key fitting a Lock.

Question 2

Sites Of Production Of Amylase, Protease And Lipase

Answer 2

Amylase : Salivary glands, Pancreas
Protease : Stomach, Pancreas and Small Intestine
Lipase : Pancreas and Small Intestine

Question 3

Amylase Breaks Carbohydrates Into…

Answer 3

Simple sugars

Question 4

Protease Breaks Proteins Into…

Answer 4

Amino Acids

Question 5

Lipase Breaks Lipids Into…

Answer 5

Glycerol + Fatty Acids

Question 6

Bile

Answer 6

Bile is made in the liver and stored in the gall bladder. It is alkaline to
neutralise 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 7

The Heart

Answer 7

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 8

Arteries

Answer 8

Carry oxygenated blood away from heart to the rest of the body.
They have thick walls and run close to the surface of the Skin.

Question 9

Veins

Answer 9

Carry de-oxygenated blood to the heart.

Thin walls and have valves to prevent backflow of blood.

Question 10

Capillaries

Answer 10

Huge network of tiny vessels which link the arteries and veins.
Oxygen and glucose can diffuse out of bloodstream and into cells easily due to very thin walls.

Question 11

The Aorta

Answer 11

The left ventricle pumps oxygenated blood around the body in a big artery called the Aorta.

Question 12

Vena Cava

Answer 12

A large vein carrying de-oxygenated blood into the Heart.

Question 13

Pulmonary Artery

Answer 13

The artery carrying blood from the right ventricle of the heart to the lungs for oxygenation.

Question 14

Pulmonary Vein

Answer 14

A vein carrying oxygenated blood from the lungs to the left atrium of the heart.

Question 15

Coronary Arteries

Answer 15

An artery supplying blood to the heart.

Question 16

Coronary Heart Disease

Answer 16

In coronary heart disease layers of fatty material build up inside the
coronary arteries, narrowing them. This reduces the flow of blood
through the coronary arteries, resulting in a lack of oxygen for the heart
muscle.

Question 17

Treating Coronary Heart Disease

Answer 17

• Stents are used to keep the coronary arteries open.
• Statins are widely used to reduce blood cholesterol levels which slows down the rate of fatty material deposit.
• Bypass Surgery replacing the narrow Coronary arteries, with bits of vein from other parts of body.
• In the case of heart failure a donor heart, or heart and lungs can be transplanted. Artificial hearts are occasionally used to keep patients alive whilst waiting for a heart transplant, or to allow the heart to rest as an aid to recovery.

Question 18

Leaky Valve Replacement

Answer 18

Mechanical valves are made from Titanium and polymers - last a long time.
However, you need to take medicine for the rest of your life to prevent blood clots.

Biological valves are from other animals and do not require medicine.
However, they only last 12-15 years.