Proteins And Mutations

Question 1

Describe enzymes

Answer 1

Proteins
Molecules that speed up a chemical reaction
Working best at a particular temperature

Question 2

What is the active site?

Answer 2

substrates molecules fit into when a reaction takes place

Question 3

Describe gene mutations

Answer 3

Changes to genes

Question 4

What are proteins made of?

Answer 4

Long chains of amino acids

Question 5

Describe some functions of proteins

Answer 5

Collagen, structural
Insulin, hormones
Haemoglobin, carrier molecule
Enzymes, chemical reactions in body

Question 6

How are proteins unique?

Answer 6

Each protein has its own number and sequence of amino acids, which results in differently shaped moleucles, which have different functions.

Question 7

Describe enzymes

Answer 7

• Biological catalysts
• Catalysing chemical reactions occurring in living cells: respiration, photosynthesis, photosynthesis, protein synthesis
• having a high specificity for their substrate

Question 8

Explain how enzyme activity is affected by pH and temperature

Answer 8

• lower collision rates at low temperatures
• denaturing at extremes of pH and high temperatures
• denaturing as an irreversible change inhibiting enzyme function
• denaturing changing the shape of the active sit

Question 9

Explain the specificity of enzymes in terms of the lock and key mechanism

Answer 9

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

Question 10

Formula for Q10

Answer 10

Q10 = rate at higher temperature / rate at lower temperature

Question 11

Describe how changing temperature and pH, away from the optimum, will change the rate of reaction of an enzyme-catalysed reaction

Answer 11

Increase in temperature increases the number of collision and so there is in the enzyme activity. Above optimum temperature enzymes are damaged, decreasing enzyme activity. As the pH increases or decreases, the enzyme becomes less and less effective.

Question 12

What may gene mutations lead to?

Answer 12

The production of different proteins

Question 13

How do mutations occur?

Answer 13

Spontaneously but can be made to occur more often by radiation or chemicals

Question 14

Can mutations be harmful?

Answer 14

Yes but may be beneficial or have no effect

Question 15

Understand that only some of the full set of genes are used in any one cell

Answer 15

Some genes are switched off

Question 16

What do the genes that are switched on determine?

Answer 16

The functions of a cell

Question 17

Explain how changes to genes alter, or prevent the production of the protein which is normally made

Answer 17

The mutations change the sequence of amino acids that the genes usually code for, so different proteins are made, which causes the nature of that particular gene to change.

Question 18

Recall some examples of protein

Answer 18

Collagen
Insulin
Haemoglobin