Topic 2 - Organisation

Question 1

Explain why it is important that we get enough iron in our diet.

Answer 1

Iron is an important component of haemoglobin

Haemoglobin is the protein in red blood cells that allows them to transport oxygen around the body

A lack of iron (and hence haemoglobin), can lead to anaemia, where we can’t transport enough oxygen to our tissues.

Question 2

Why do we need fibre?

Answer 2

To help food move through our intestines

Question 3

What are the monomers that join together to form proteins called?

Answer 3

Amino acids

Question 4

Is glucose a monomer or a polymer?

Answer 4

Is glycogen a monomer or a polymer?

Question 5

Proteins are broken down in two organs,

Answer 5

the small intestine and the stomach.

Question 6

Proteins are mainly made from carbon, hydrogen, oxygen, and which other element?

Answer 6

Nitrogen

Question 7

Lipids are only broken down in the:

Answer 7

small intestine

Question 8

Lipids are made from a single ???? molecule and three fatty ????? molecules.

Answer 8

glycerol ——-acid

Question 9

Which organs in the body produce amylase

Answer 9

Salivary glands
Pancreas
Small intestines

Question 10

Starch is broken down by the enzyme ????? into maltose molecules. These are then broken down further by ????? into glucose.

Answer 10

amylase
maltase

Question 11

Proteins are broken down by a group of enzymes called proteases into individual monomers called amino acids.

Answer 11

proteases
amino acids

Question 12

Which two of the following are examples of protease enzymes?

Answer 12

Trypsin
Pepsin

Question 13

Lipids are broken down by lipase enzymes, and converted into glycerol and fatty acids.

Answer 13

lipase
glycerol
fatty acids

Question 14

Which organs in the body produce lipase enzymes?

Answer 14

Small intestines
Pancreas

Question 15

When we chew food, our teeth physically break the food down into smaller pieces. How does this help?

Answer 15

It increases the surface area for enzymes to act on
It make the food easier to swallow

Question 15

The digestive system has two main roles. Briefly describe each of them.

Answer 15

Digestion - process of breaking down large food molecules into smaller molecules

Absorption - process of absorbing these small food molecules into the body

Question 15

2 roles of bile

Answer 15

Bile is made by the liver, but it is stored in the gallbladder,
After we have meal, it is released into the small intestine where it helps in two ways:
One is to emulsify lipids, which means separate large droplets of lipid into smaller droplets.
The other is to neutralise the acid from the stomach, which bile can do because it is alkaline

Question 16

What is the official name for the tube that carries food from the mouth to the stomach.

Answer 16

Oesophagus

Question 17

Which enzymes does the pancreas produce?

Answer 17

Amylase, proteases, and lipases

Question 18

Which enzymes does the small intestine produce?

Answer 18

Amylase, proteases, and lipases

Question 19

What is the main role of the large intestine?

Answer 19

Absorb water

Question 20

Villi are finger-like protrusions of the small intestine that are responsible for absorbing nutrients into the body.

Give three ways in which villi are adapted for this role.

Answer 20

There are many villi, which gives them a large total surface area over which to absorb nutrients

They have a single layer of cells on their surface, which means nutrients only have to diffuse a short distance.

They have a good blood supply which maintains a strong concentration gradient between the lumen and the blood

The cells lining the villi have microvilli on their surface, which further increases the surface area

Question 21

Which test is used to detect the presence of reducing sugars

Answer 21

Benedict’s test

Question 22

What does iodine test for?

Answer 22

Starch

Question 23

To test for proteins we can use

Answer 23

biuret solution.

Question 24

Iodine solution is used to test for the presence of starch. If starch is present, which colour change takes place?

Answer 24

Orange to blue-black

Question 25

Biuret reagent can be used to test for the presence of proteins. If protein is present, what colour change takes place?

Answer 25

Blue to lilac / purple

Question 26

Which reagent is used to test for the presence of lipids?

Answer 26

Sudan III stain

Question 27

The three parts of the circulatory system are

Answer 27

the blood, the blood vessels, and the heart

Question 28

On each side of the heart, the atrium and ventricle are separated by a ?? which prevents what?

Answer 28

On each side of the heart, the atrium and ventricle are separated by a valve, which prevents the blood from flowing backwards.

Question 29

Which blood vessel carries deoxygenated blood from the heart to the lungs?

Answer 29

Pulmonary artery

Question 30

The journey of blood around the body

Answer 30

Body tissues ➔ vena cava ➔ right atrium ➔ right ventricle ➔ pulmonary artery ➔ lungs ➔ pulmonary vein ➔ left atrium ➔ left ventricle ➔ aorta ➔ body tissues

Question 31

Which blood vessel carries oxygenated blood from the heart to the body?

Answer 31

Aorta

Question 32

The movement of blood between the ventricles and atria:

Answer 32

The walls of the atria contract, pushing blood into the relaxed ventricles. The walls of the ventricles contract, pushing blood out of the heart. At the same time, more blood will enter the now-relaxed atria. The cycle repeats.

Question 33

Which statement is always true regarding arteries?

Answer 33

They carry blood away from the heart

Question 34

Which statements is always true for veins?

Question 35

Structure and function of arteries

Answer 35

Arteries are large and carry blood at a very high pressure. Artery walls have a thick middle layer, containing both muscle and elastic tissue. The muscle tissue provides strength, and allows the arteries to direct blood flow. The elastic tissue allows the arteries to stretch and recoil. Compared to their walls, arteries have a relatively narrow lumen, which keeps the blood pressure high.

Question 36

Structure and function of capillaries

Answer 36

Capillaries are the smallest of the three blood vessels. The role of capillaries is to exchange nutrients and waste products with the tissues. Capillary walls are permeable, meaning substances are able to move through them. Their walls are also only one cell thick which means a short distance for diffusion. Capillaries carry blood at a low pressure and have a lower rate of flow than arteries.

Question 37

Structure and function of veins

Answer 37

The role of veins is to carry blood from the body (or lungs) back to the heart. Veins are a similar size to arteries, but they have relatively thin walls and a relatively small lumen This is because they carry blood at a much lower pressure. Veins also contain valves to prevent the blood from flowing backwards.

Question 38

In which order does blood flow through the three types of blood vessels?

Answer 38

Heart ➔ artery ➔ capillaries ➔ veins ➔ heart

Question 39

What is the role of red blood cells?

Answer 39

To carry oxygen from the lungs to the tissues

Question 40

large proteins

Answer 40

haemoglobin

Question 41

How are red blood cells adapted for their function?

Answer 41

They have no nucleus to fit in more haemoglobin They have a biconcave shape to increase their surface area

Question 42

What is the role of white blood cells?

Answer 42

To defend against pathogens

Question 43

is the process by which a white blood cell binds to, and then engulfs a pathogen, in order to destroy it.

Answer 43

Phagocytosis

Question 44

How do antibodies help defend against pathogens?

Answer 44

They bind to pathogens and help immune cells destroy them

Question 45

What is the role of platelets?

Answer 45

To clot the blood when a blood vessel breaks

Question 46

Give two reasons why it is so important that our blood clots when we are cut.

Answer 46

Prevents blood from leaving the blood vessels Prevents pathogens from entering the blood

Question 47

What is the role of blood plasma?

Answer 47

To carry substances and cells around the body

Question 48

Coronary heart disease

Answer 48

Coronary arteries branch out of the aorta and supply oxygenated blood to the heart muscle. In coronary heart disease, layers of fatty material build up inside the coronary arteries, causing the lumen to get narrower. This reduces the flow of blood through the coronary arteries, resulting in a lack of oxygen and nutrients for the heart muscle. This can cause chest pain as the heart muscle is starved of oxygen, and in severe cases, can cause a heart attack.