3.2 ATP: Energy Currency of the Cell

Question 1

ATP:
Adenosine Triphosphate

Answer 1

ATP directly supplies energy that powers cellular function

Universal energy “currency”

Question 2

ATP helps power;

Answer 2

1. Mechanical Work
   Beating cilia, muscle mvmt, chromosome mvmt
2. Transport Work
   Pumping substances across membranes against
   their concentration gradient
3. Chemical Work
   Providing chemical potential energy for non-
   spontaneous, endergonic rxns

(e.g., proteinsynthesis and DNA replication)

Question 3

ATP Hydrolysis and Free
Energy

Answer 3

Specifically the crowded, negatively charged phosphate groups repel one another and
weaken the bonds holding them together

These bonds can be easily broken by Hydrolysis
(adding H2O) to release energy

Hydrolysis breaks off one phosphate group,
forming ADP and an inorganic phosphate (Pi) and Energy

Question 4

Energy Coupling

Answer 4

using energy released from one reaction to drive another reaction

Question 5

Phosphorylation

Answer 5

attaching a phosphate group to another organic molecule

results in the molecule gaining FREE ENERGY and becoming more reactive

Question 6

Energy Coupling requires an enzyme to…

Answer 6

bring ATP close to the reactant molecule in an endergonic reaction

the enzyme has specific sites where ATP and the reactant molecule bind

Question 7

Most work carried out in a cell is dependent on…

Answer 7

phosphorylation for energy

Question 8

Regeneration of ATP

Answer 8

Cells make ATP by combining ADP + Pi

This requires FREE ENERGY (thus is endergonic)

Question 9

Energy needed for ATP synthesis comes from

Answer 9

the exergonic breakdown of complex molecules in the
food we eat (carbs, fats, and proteins)

Question 10

At least 10 million times every second,

Answer 10

ATP molecules are hydrolyzed and resynthesized in a typical cell

Question 11

The continued breakdown and resynthesis of ATP is called the

Answer 11

ATP Cycle

Question 12

The ability for ATP to
couple to so many
different endergonic
reactions gives ATP its

Answer 12

“universal” characteristic

ATP is the Universal Energy
Currency

Question 13

The ability to assemble
ATP using energy from a
variety of food molecules ensures

Answer 13

all vital reactions in a cell
can be performed