B3: Living And Growing

Question 0

Cell membrane controls what?

Answer 0

Movement into and out of the cell.

Question 1

Where do most chemical reactions in cells take place?

Answer 1

In the cytoplasm. It may contain mitochondria which is where most of the energy is released in respiration.

Question 2

Nucleus contains what?

Answer 2

Contains genetic information and controls what the cell does. It has a membrane extending from it, onto which ribosomes are attached.

Question 3

Respiration takes place in the what?

Answer 3

It takes place in the mitochondria, providing energy for life processes.
Liver and muscle cells have particularly large numbers of mitochondria because they have a high energy requirement.

Question 4

The nucleus of each cell contains a complete set of genetic instructions called what?

Answer 4

Genetic Code.
The information is carried by genes on chromosomes, which are long coils of chemical called DNA AKA Deoxyribonucleic Acid.

Question 5

The genetic code controls what?

Answer 5

Cell Activity and some characteristics of the whole organism.

Question 6

A DNA molecule is made of 2 strands coiled around each other in what?

Answer 6

A double helix (Spiral).

Question 7

The genetic code is in the form of what?

Answer 7

A chemical code made up of 4 bases. These bases bond together in pairs, forming the cross-links (like rungs on a ladder) which hold the 2 strands of DNA together.

Question 8

The highly specialised structure of DNA was first put forward by who in what year?

Answer 8

1953 by scientists James Watson and Francis Crick.

Question 9

What are proteins and why are they important?

Answer 9

Proteins are needed in cells because they are a vital component in the construction of membranes.

Question 10

What function does the following protein specialise in?

- Collagen

Answer 10

It is an important structural protein found in connective tissue.

Question 11

What function does the following protein specialise in?

- Insulin

Answer 11

It is a hormone that helps control blood sugar levels.

Question 12

What function does the following protein specialise in?

- Haemoglobin

Answer 12

It is a carrier protein found in red blood cells, which binds with Oxygen.

Question 13

What function does the following protein specialise in?

- Enzymes

Answer 13

Controls chemical reactions in the body.

Question 14

What are Enzymes?

Answer 14

Proteins that act as biological catalysts. They speed up chemical reactions, including those that take place in living cells, e.g. respiration, photosynthesis and protein synthesis.

Question 15

Enzymes are highly what?

Answer 15

Specific.
Each one will speed up only a particular reaction. Enzymes have active sites, regions of enzyme molecule which bind to substrate molecules temporarily and allow the substrate to be changed.

Question 16

What effects the rate of a reaction catalysed by an enzyme?

Answer 16

Changing temperature and pH.

Question 17

How do you measure the rate of a reaction?

Answer 17

The rate of an enzyme-controlled reaction can be expressed as a Q10 value by comparing the rate at a particular temperature and dividing it by the rate at a temperature 10 degrees C or lower.

Q10 =
Rate at temperature, t
Divided By
Rate at temperature, t - 10 degrees C

Question 18

What is the lock and key mechanism?

Answer 18

Each enzyme has a different number and sequence of amino acids. This gives it a unique 3D shape, which includes an active site that only a specific reactant can fit into. Like a key in a lock.

Question 19

Enzyme molecules are denatured by what?

Answer 19

High temperature and extreme pH. Bonds in protein break and shape of its active site is changed irreversibly, so lock and key mechanism no longer works.

Question 20

What are Platelets?

Answer 20

Tiny pieces of cell, which have no nucleus. They clump together when blood vessel becomes damaged and form a meshwork of fibres to produce a clot.

Question 21

What is a Plasma?

Answer 21

Transports:

• Carbon dioxide from cells to lungs
• Glucose and other digested food products from small intestine to cells
• Waste products from liver to kidneys
• Hormones to target organs
• Antibodies to fight disease.

Question 22

What are white blood cells?

Answer 22

Protect the body against disease. Some have a flexible shape, which allows them to engulf invading microorganisms. Others produce antibodies to attack microorganisms.

Question 23

What are red blood cells?

Answer 23

Transport oxygen from lungs to the tissues. They are small and flexible, so they can pass through narrow blood vessels. They have no nucleus, so can be packed with haemoglobin. The shape of cells increase their surface area for transferring oxygen.

Question 24

What are arteries?

Answer 24

Carries blood away from heart.

Question 25

What are veins?

Answer 25

Transports blood to the heart.

Question 26

What are capillaries?

Answer 26

Involved in exchanging materials with the tissues.

Question 27

The human circulatory system is a what?

Answer 27

Double circulatory system. Meaning it has 2 loops. One carries blood from heart to lungs, then back to heart (pulmonary). And the other carries heart from heart, to all other parts of the body, then back to the heart (systemic).

Question 28

Most of the wall of the heart is muscle, but what are the 4 chambers called?

Answer 28

Lower Chambers: Ventricles (Larger and muscular because they are pumping out of the heart) The right pumps to the lungs. The left is more muscular because it pumps around the whole body.
Upper Chambers: Atria (Smaller and less muscular) Receive blood coming back to the heart through veins.

Valves in the heart make sure the blood flows in the correct direction through the heart.

Question 29

Plant and animal cells contain what?

Answer 29

A nucleus, cell membrane, mitochondria, and cytoplasm. Plant cells also contain chloroplasts, a cellulose cell wall and a vacuole.

Question 30

Plant and animal cells contain what?

Answer 30

A nucleus, cell membrane, mitochondria, and cytoplasm. Plant cells also contain chloroplasts, a cellulose cell wall and a vacuole.

Question 31

Plant and animal cells contain what?

Answer 31

A nucleus, cell membrane, mitochondria, and cytoplasm. Plant cells also contain chloroplasts, a cellulose cell wall and a vacuole.