1.6 Metabolic pathway

Question 1

Whats a catabolic reaction? (2)

Answer 1

• Breakdown of molecules into sub units

- Releases energy.

Question 2

Whats an anabolic reaction? (2)

Answer 2

• Build up of molecules from sub-units

- requires energy

Question 3

What are catalysts/ how do they affect a reaction? (3)

Answer 3

• They speed up the process
• Remain unchanged at end of reaction
• Lowers activation energy

Question 4

How might you control metabolic pathways? (1)

Answer 4

Through the presence or absence of key enzymes

Question 5

What does the enzyme, active site and substrate look like? (1)

Answer 5

THINK!

Question 6

How does low and high substrate concentration affect rate of reaction/ enzyme reactions? (2)

Answer 6

Low- Not enough substate to connect to all the active sites on the enzyme

High- Too many substrates and too little enzymes with active sites

Question 7

What are factors which affect enzyme activity? (3)

Answer 7

• PH
• Temperature
• Supply of substrate concentration

Question 8

How does induced fit work? (2 not separate)

Answer 8

-Its the idea about the substrate being able to fit into the active site and for the enzyme to then carry out its catalytic function (speed up reaction)

Question 9

What happens when affinity is too low compared to being too high? (2)

Answer 9

• Too low the substrate will come apart from the active site (Enzyme doesn’t like the substrate) (weaker forces)
• High and the substrate and active site will bond chemically (stronger forces)

Question 10

How would it work for enzyme A to create a chain reaction creating enzyme B and so forth? (1)

Answer 10

-Substate joins active site on enzymes, the product of that then goes on to enzyme B and this chains

Question 11

How would it work for enzyme A to reverse from enzyme B to A? (1)

Answer 11

-You would have to remove the product from enzyme B (could be done with low affinity) and so enzyme B will become in active and will go back to enzyme A

Question 12

In a respiration cell what is always on? (1)

Answer 12

-Enzymes are always switched on

Question 13

What are the inhibitors? (3)

Answer 13

• Competitive
• Non-competitive
• Feedback by end product

Question 14

Tell me all about competitive inhibition? (3)

Answer 14

• The inhibitor fights substrate for place in active site
• High enough substrate concentration means it will out number inhibitor and will get active site
• Can reduce rate of reaction

Question 15

Tell me about non-competitive inhibition? (2)

Answer 15

• The inhibitor joins anywhere essentially shutting down a chance for substrate to join active site
• Severely reduces rate of reaction

Question 16

Tell me about feedback inhibition? (3)

Answer 16

• End product in metabolic pathway binds to enzyme at start of pathway
• The feedback inhibitor is used to regulate the metabolic process
• Used to control pathways

Question 17

What are enzymes?

Answer 17

-Protein folded into specific shape, exposing the active site

Question 18

How could a pathway be reversed? (1)

Answer 18

-Depends on concentration (Think about the chain)

Question 19

Why does the graph level off? (1)

Answer 19

-Due to concentration of substrate and active sites from enzyme available

Question 20

What is metabolism?

Answer 20

Controlled pathways of enzyme catalysed reactions within a cell

Question 21

State the term which describes all the chemical reactions which take place within a living cell? (1)

Answer 21

-Metabolism

Question 22

Name a cellular reaction which requires energy? (3)

Answer 22

• Protein synthesis
• DNA replication
• Anabolic

Question 23

What is metabolism?

Answer 23

The process of chemical reaction in order to maintain life