1 Biological Molecules- ATP

Question 1

What is ATP and how is it formed?

Answer 1

Adenosine triphosphate is a nucleotide derivative (modified) formed from a ribose molecule, an adenine molecule and 3 phosphate groups

Question 2

What is the function of ATP?

Answer 2

-Small, relatively simple molecule
-Primary energy currency of cells (like money); as it’s small and easy to move in & out of cells + water soluble
-Used to power most energy-requiring cellular reactions

Question 3

What is the hydrolysis of ATP, and what is it catalysed by?

Answer 3

Happens when a cell needs energy
Equation= ATP + H2O –> ADP + Pi (+ energy)
Hydrolysis of ATP to adenosine diphosphate and an inorganic phosphate group is catalysed by enzyme ATP hydrolase

Question 4

Why is energy released during this hydrolysis and what is it used for?

Answer 4

One of the phosphate bonds is broken
This energy is used to perform work inside the cell

Question 5

How does the hydrolysis of ATP help energy-requiring reactions in cells?

Answer 5

The hydrolysis of ATP can be coupled to other reactions in cells which need energy
e.g. transmembrane sodium-potassium pump (Na+ K+) :
-Energy is released from the hydrolysis of ATP
-Energy is needed to power the pump driving Na+ out of the cell and K+ into it

Question 6

What is phosphorylation?

Answer 6

The inorganic phosphate released in ATP hydrolysis can be used to phosphorylate other compounds, often making them more reactive

Question 7

How is ATP resynthesised + equation?

Answer 7

ADP + Pi (+energy) –> ATP + H2O
ATP is resynthesised by the condensation of ADP and an inorganic phopshate
This reaction is catalysed by ATP synthase during photosynthesis or respiration

Question 8

What does the regeneration of ATP require?

Answer 8

An input of energy