Biolodgy Revison S3

Question 1

Function of the cell membrane

Answer 1

controls what enters and leaves a cell

Question 2

Function of the cytoplasm

Answer 2

Site of chemical reactions in the cell.

Question 3

Function of the nucleus in an animal cell

Answer 3

Controls the cell’s activities

Question 4

Where in an animal cell does protein synthesis occur?

Answer 4

Ribosome

Question 5

Function of the vacuole in a plant cell

Answer 5

Stores cell sap and maintains cell shape.

Question 6

Function of the cell wall in plant, bacterial and fungal cells

Answer 6

Provides support and gives structure to the cell.

Question 7

Where in the cell does aerobic respiration occur?

Answer 7

Mitochondria

Question 8

Which cell structure is the site of photosynthesis?

Answer 8

Chloroplast

Question 9

Give three structures that are found in both plant and animal cells

Answer 9

Nucleus Cytoplasm Cell membrane

Question 10

Give two structural differences between plant and animal cells

Answer 10

A plant cell has a cell wall and chloroplasts , an animal cell does not

Question 11

Give two differences between an animal and a bacterial cell

Answer 11

A bacterial cell has a cell wall and a plasmid, an animal cell does not

Question 12

What substance is the main component of plant cell walls?

Answer 12

Cellulose

Question 13

Why do scientists use a stain when viewing cells under a microscope?

Answer 13

Stains enable us to see cells more clearly when viewing under a microscope.

Question 14

What would the overall magnification be if the x40 objective lens was used to view cells?

Answer 14

400

Question 15

What would the overall magnification be if the X10 objective lens was used to view cells?

Answer 15

100

Question 16

A plant cell is 60μm in length, how many millimetres is this?

Answer 16

0.06mm

Question 17

What is a plasmid, and in which type of cell is it found?

Answer 17

Small, circular pieces of genetic material that can be transferred between organisms. Found in bacterial cells.

Question 18

What is diffusion?

Answer 18

Diffusion is the movement of molecules from an area of high concentration to an area of low
concentration until they are evenly spread.

Question 19

In what kind of substances does diffusion occur?

Answer 19

Solid,liquid and gas

Question 20

Why is diffusion able to happen in a gas?

Answer 20

Diffusion happens in gases as the particles move freely and quickly therefor bump into eachother.

Question 21

Why does diffusion happen very slowly in a solid?

Answer 21

The particles are fixed

Question 22

Name 2 substances that are needed by cells

Answer 22

Oxygen and glucose

Question 23

Name 1 waste product produced by cells

Answer 23

Carbon dioxide

Question 24

Why does the litmus paper turn from red to blue?

Answer 24

It shows the change from an area of high concentration to an area of low concentration until the molecules were evenly spread

Question 25

Why would oxygen move into a cell?

Answer 25

aerobic respiration.

Question 26

Why would glucose move into a cell?

Answer 26

provide energy to make ATP during aerobic respiration.

Question 27

What is a concentration gradient?

Answer 27

A concentration gradient occurs when the concentration of particles is higher in one area than another.

Question 28

What is a catalyst?

Answer 28

A substance which speeds up a chemical reaction, without being altered or changed during the process.

Question 29

Describe the effect of increasing temperature on enzyme activity

Answer 29

Increasing temperature increases enzyme activity and the reaction rate until the enzyme’s optimum temperature is reached. Different enzymes have different optimum temperatures.

Question 30

Explain how Amylase functions to speed up the breakdown starch

Answer 30

Amylase allows the starch molecule to break down into many smaller maltose molecules

Question 31

An experiment was set up to investigate the effect of pH on enzyme activity. Give three variables
that would have to be kept constant when carrying out this experiment.

Answer 31

Volume of pH, tools used and time taken.

Question 32

What is the difference between the independent variable and the dependent variable in an
investigation?

Answer 32

The variable that is being purposely altered in an investigation and the variable is being measured in an investigation to get the results. The dependent variable changes because of the changes made to the independent variable.

Question 33

Explain why Catalase is the only enzyme that can catalyse the breakdown of hydrogen peroxide

Answer 33

Catalase is specific to hydrogen peroxide

Question 34

What is meant by the term ‘biological catalyst’

Answer 34

An enzyme is a biological catalyst and is almost always a protein. Speeds up the chemical reaction

Question 35

What is the name given to the part of an enzyme where the substrate binds?

Answer 35

Active site

Question 36

Name the subunits of protein molecules

Answer 36

Amino acids

Question 37

Describe what happens when an enzyme denatures?

Answer 37

When the shape of a protein molecule irreversibly changes. This can be caused by high temperatures or a pH outside the working range.

Question 38

Name the enzyme that speeds up the breakdown of Hydrogen peroxide?

Answer 38

catalase

Question 39

What is meant by ‘optimum pH’?

Answer 39

The conditions e.g. temperature or pH, at which a reaction will occur at the fastest rate.

Question 40

What could be done to make the results of an experiment more reliable?

Answer 40

Repeat the experiment.

Question 41

The working pH range of Catalase is pH 6-9, but it’s optimum is pH 7. Explain what would happen
to the activity of Catalase if pH was increased from 6 to 11.

Answer 41

The catalase stops working

Question 42

What name is given to the molecule which an enzyme acts on?

Answer 42

substrates

Question 43

What is a degradation reaction?

Answer 43

A reaction in which a large molecule is broken down into one or more smaller molecules.

Question 44

Name the substance from which all enzymes are made

Answer 44

amino acids