B4

Question 1

What are enzymes?

Answer 1

Proteins - they consist of long chains of amino acids

Question 2

What do enzymes do?

Answer 2

Speed up reactions. They are biological catalysts

Question 3

What is the active site of an enzyme and what does it do?

Answer 3

It is where the enzyme breaks down the substrate

Question 4

Describe how enzymes break down substrates

Answer 4

Each enzyme has an active site designed to breaks down a specific substrate
The substrate goes into the active site (like a key in a lock)
The reaction occurs and breaks down the substrate
The products are then released from the active site and used by the body

Question 5

What is denaturing?

Answer 5

When the pH or temperature are too high, the active site permanently changes shape, so it cannot perform the reaction as the substrate doesn’t fit

Question 6

What is the word equation for photosynthesis?

Answer 6

carbon dioxide + water –> glucose + oxygen

Question 7

Why can photosynthesis only take place during the day?

Answer 7

Light energy is used to turn the two reactants into the products, without the sun the reaction can’t take place

Question 8

What is glucose used for in plants?

Answer 8

Turned into chemicals so the plant can grow such as cellulose, chlorophyll, protein
Converted into starch for storage
Used in respiration to get energy

Question 9

What makes up a human cell and what does each part do?

Answer 9

Nucleus - stores genetic information
Cytoplasm - where anaerobic respiration takes place
Cell Membrane - allows gases and water in and out
Mitochondria - where aerobic respiration takes place

Question 10

What makes up a plant cell what does each part do?

Answer 10

Nucleus - stores genetic information
Cytoplasm - where anaerobic respiration takes place
Cell Membrane - allows gases and water in and out
Mitochondria - where aerobic respiration takes place
Cell Wall - lets water and chemicals into the cell
Vacuole - gives the cell structure

Question 11

What makes up a bacterium cell what does each part do?

Answer 11

Circular DNA - stores genetic information
Cytoplasm - where anaerobic respiration takes place
Cell membrane - allows gases and water in and out
Cell wall - lets water and chemicals into the cell
Flagella - allows the cell to ‘swim’ around

Question 12

What is diffusion?

Answer 12

A chemical moves from HIGH concentration to LOW concentration
It’s a passive process

Question 13

How do plants use diffusion?

Answer 13

Carbon dioxide and oxygen moving in and out of leaves

Question 14

What is osmosis?

Answer 14

It is a special type of diffusion involving water
Water moves from HIGH concentration to LOW concentration through a partially permeable membrane
It’s a passive process

Question 15

Describe osmosis in terms of concentration

Answer 15

It is the movement of a DILUTE solution to a CONCENTRATED solution

Question 16

How do plants use osmosis?

Answer 16

Water into plant roots from soil and across the roots

Question 17

What is active transport?

Answer 17

The movement of chemicals across membranes into a plant

It requires energy from the plant

Question 18

How do plants use active transport?

Answer 18

To absorb nitrates from the soil as they are in a higher concentration in the soil than in the plant

Question 19

How can the rate of photosynthesis be limited?

Answer 19

By temperature, levels of carbon dioxide and light intensity

Question 20

After identifying the limiting factor, how would you over come it?

Answer 20

You would increase it e.g. if light was the limiting factor for the plants you were growing, you would increase the light again

Question 21

Why could temperature also end up decreasing rate of photosynthesis?

Answer 21

As it can lead to the enzymes in the plants being denatured

Question 22

What do ecologist so to assess the effects of light intensity on an area?

Answer 22

Use an identification key to identify plants
Measure how common the plants are
Use a light metre to measure the light intensity

Question 23

What is a quadrat used for?

Answer 23

To create samples to help ecologist estimate how many plants are in a selected area

Question 24

What organisms respire?

Answer 24

All organisms respire

Question 25

Where is the glucose in respiration in humans come from?

Answer 25

Starch broken down into glucose and raw glucose come from our food

Question 26

Name the respiration that uses oxygen

Answer 26

Aerobic respiration

Question 27

What is the word equation for aerobic respiration?

Answer 27

glucose + oxygen → carbon dioxide + water (+energy)

Question 28

How is excess glucose stored?

Answer 28

As starch

Question 29

How does respiration take place?

Answer 29

As a series of enzyme controlled reactions with energy being release in stages

Question 30

Name the respiration that does not use oxygen

Answer 30

Anaerobic respiration

Question 31

What is the word equation for anaerobic respiration?

Answer 31

glucose → lactic acid (+energy)

Question 32

Which type of respiration is more efficient?

Answer 32

Aerobic

Question 33

How is lactic acid broken down?

Answer 33

By blood flowing through fatigued musckes and providing enough oxygen to break it down into glucose

Question 34

What is fermentation?

Answer 34

A type of anaerobic respiration used by micro-organisms

Question 35

How can fermentation be useful to us?

Answer 35

Yeast fermentation is used to help bread rise

It also creates ethanol which we can use for a preservative, fuel and disinfectant

Question 36

What is the word equation for fermentation?

Answer 36

glucose → ethanol + carbon dioxide (+energy)