3.1.6 ATP

Question 1

State the components of ATP

Answer 1

Adenine

Ribose

3 phosphate groups

Question 2

What is meant by ADP

Answer 2

Adenosine diphosphate is when one phosphate group is removed

Question 3

Bonds between phosphate groups have a _____ ________________________ _____________, so are _________ and easily broken, when bonds break, they release ‘________ _______________’ of energy about 30kJ

Answer 3

• Low activation energy
• Unstable
• ‘Small packets’

Question 4

Explain the hydrolysis and synthesis of ATP

Answer 4

• Condensation - phosphate added, water removed and use of ATP synthase
• Hydrolysis - phosphate removed, water added, and use of ATP hydrase

Question 5

2 roles of ATP

Answer 5

1. Good immediate source of energy, unstable phosphate bonds make it a bad storage molecule
2. Cells only store a few seconds worth in ‘small packets’ - easily resynthesised

Question 6

It’s a better immediate source of energy than glucose because…

Answer 6

1. Molecule releases much less energy than glucose, more manageable and less heat, so less heat denatured enzymes
2. Hydrolysis of ATP is single step, so immediate release of energy

Question 7

Why do muscle cells have large mitochondria

Answer 7

ATP can’t be stored, so larger mitochondria increases rate of aerobic respiration producing ATP faster

Question 8

Which process produces ATP as a product (1)

Answer 8

Photosynthesis and respiration
Allow in any order

Question 9

Metabolic processes (ATP)

Answer 9

Provides energy to make monomers to polymers

Question 10

Movement

Answer 10

Muscle contraction

Question 11

Active transport

Answer 11

Changes shape of carrier protein in cell surface membrane so molecules can move against concentration gradient

Question 12

Secretion

Answer 12

Forms and moves vesicles to secrete products

Question 13

Activation of molecules

Answer 13

Inorganic phosphate used to phosphorylate other compounds to make them more reactive

Question 14

A scientist did an experiment measuring how concentration of ATP solution affects length of muscle tissue.

He concluded that as the concentration of ATP solution increases, the length of muscle tissue decreases.

Explain why (1)

Answer 14

More ATP so more energy produced so more muscle contraction

Question 15

ATP synthase has two functions.

• It catalyses the synthesis of ATP
• It allows the movement of H+ ions

Suggest how the shape of ATP synthase allows it to have these two functions.

Explain your answers (4)

Answer 15

(Catalyses the synthesis of ATP)
1. Active site complementary to ADP + Pi;
2. Enzyme-substrate complex forms;

(Allows the movement of H+ ions)
3. Channel (in membrane/protein/enzyme);
4. Allows facilitated diffusion of H+

OR

(Channel) has tertiary structure specific for (only)
H+
;