Deck 1 - Higher biology - Unit 2 Metabolism and survival - Key area 1 metabolic Pathways

Question 1

What are metabolic pathways?

Answer 1

Metabolic Pathways are integrated and controlled pathways of enzyme - catalysed reactions within a cell.

Question 2

Do metabolic pathways have;

1. reversible steps
2. irreversible steps
3. alternative routes
4. no alternative routes

Is it;
A. 1 and 4 only
B. 2 and 3 only
C. 3 and 4 only
D. 1 and 3 only
E. 1 and 2 only
F. 2 and 4
G. All of them
H. Just 1, 2 and 3
I. Just 2, 3 and 4
J. Just 1, 3 and 4
K. Just 1, 2 and 4

Answer 2

H

Question 3

Are reactions within metabolic pathways anabolic or catabolic?

Answer 3

Both

Question 4

What are anabolic reactions?

Answer 4

Anabolic reactions build up large molecules from small molecules and require energy.

Question 5

What are catabolic reactions?

Answer 5

Catabolic reactions break down large molecules into smaller molecules and release energy.

Question 6

Where are protein pores, pumps and enzymes embedded into?

Answer 6

Membranes

Question 7

What are metabolic pathways controlled by?

Answer 7

Metabolic pathways are controlled by the presence or absence of particular enzymes and the regulation of the rate of reaction of key enzymes.

Question 8

Describe and compare anabolic and catabolic reactions

Answer 8

1. Anabolism is a synthesis/build up NB: For full marks to be awarded
reaction candidates must have provided at
OR least 1 correct point for anabolism
AND at least 1 point for catabolism
Anabolism is build-up of molecules/
substances
OR
Anabolism is where simple molecules
are built up into more complex/large
molecules
1
2. Anabolism requires the input/
take up… of energy/ATP
1
3. Catabolism is breakdown/
degradation …..
of….. molecules/substances
OR
Catabolism is a….. break
down/degradation……. reaction
OR
Catabolism is where complex/large
molecules are changed into more
simple molecules
1
4. Energy/ATP is released/given off
in catabolism
1 
NOT − catabolism does not require
energy
5. Both can have reversible and
irreversible steps
1
6. Both can have alternative
route
1

Question 9

Describe competitive and non-competitive inhibition of enzyme action.

Answer 9

1. A competitive inhibitor
binds to/blocks the active site
2. Competitive inhibition is
reversed/reduced by increasing substrate
3. Non-competitive inhibition is
where a molecule binds to the enzyme not on the active site concentration
4. Non-competitive inhibitor 1
changes (the shape of) the
active site
5. Non-competitive inhibition is
irreversible/not affected by substrate concentration