ATP

Question 1

What is an ATP molecule comprised of?

Answer 1

• Adenine
• Ribose
• Phosphates

Question 2

What is adenine?

Answer 2

A nitrogen-containing organic base.

Question 3

What is ribose?

Answer 3

A sugar molecule with a 5-carbon ring structure (pentose sugar) which acts as a backbone that the other parts are attached to.

Question 4

How does ATP store energy?

Answer 4

The bonds between the phosphate groups are unstable and have low activation energy (easily broken).
They release lots of energy when broken.

Question 5

What reaction converts ATP to ADP?

Answer 5

A hydrolysis reaction.

Question 6

What enzyme catalyses the reaction that converts ATP to ADP?

Answer 6

ATP hydrolase.

Question 7

Is the conversion of ATP a reversible reaction?

Answer 7

Yes

Question 8

What kind of reaction reforms ATP from ADP?

Answer 8

A condensation reaction.

Question 9

What enzyme catalyses the reaction that converts ADP to ATP?

Answer 9

ATP synthase.

Question 10

Why isn’t ATP a good energy store?

Answer 10

Because of the instability of its phosphate bonds.

Question 11

What makes ATP a good energy donor?

Answer 11

The instability of its phosphate bonds.

Question 12

What kind of energy store is ATP?

Answer 12

An immediate energy source.

Question 13

What does ATP stand for?

Answer 13

Adenosine Triphosphate.

Question 14

How much ATP is typically stored in cells?

Answer 14

They maintain a few seconds supply which can easily be reformed from ADP produced.

Question 15

Where is ATP made?

Answer 15

In the mitochondria of the cells that need it.

Question 16

Why is ATP a better immediate energy source than glucose?

Answer 16

• ATP releases less energy than glucose but it is much more manageable than the greater release of energy by glucose.
• The hydrolysis of ATP is a single reaction whereas the breakdown of glucose requires multiple reactions so energy release takes longer.

Question 17

Which processes require ATP

Answer 17

• Metabolic processes
• Movement
• Active transport
• Secretion
• Activation of molecules

Question 18

Why is ATP required in metabolic processes?

Answer 18

It provides the energy required to build up macromolecules from their basic units.
eg: making starch from glucose

Question 19

Why is ATP required in movement?

Answer 19

Provides the energy for muscle contraction - for the filaments of muscle to slide past one another and therefore shorten the overall length of the muscle fibre.

Question 20

Why is ATP required for active transport?

Answer 20

Provides the energy to change the shape of carrier proteins in plasma membranes which allows molecules/ions to be moved against a concentration gradient.

Question 21

Why is ATP required in secretion?

Answer 21

ATP is needed to form the lysosomes necessary for the secretion of cell products.

Question 22

Why is ATP required in the activation of molecules?

Answer 22

The inorganic phosphate released during hydrolysis of ATP can be used to phosphorylate other compounds to make them more reactive (lowering the activation energy in enzyme-catalyses reactions)

Question 23

Is ATP hydrolysis an endogenic or exogenic reaction?

Answer 23

Exogenic