6.3: ATP powers cellular work by coupling exergonic reactions to endergonic reactions

Question 1

3 types of jobs of a cell

Answer 1

Chemical work: the pushing of endergonic reactions, synthesis of polymers from monomers

Transport work: the pumping of substances across membranes against the direction of spontaneous movement

Mechanical work: contractions of muscles and movement of chromosomes during cellular reproduction

Question 2

energy coupling

Answer 2

use of an exergonic process to drive an endergonic process

Question 3

what mediates energy coupling

Answer 3

ATP

Question 4

ATP(adenosine triphosphate), what are the components

Answer 4

contains sugar ribose, with a nitrogen base(adenine), and a chain of 3 phosphates

Question 5

ΔG for the hydrolysis of ATP

Answer 5

-7.3kcal/mol,

Question 6

Why does ATP release energy

Answer 6

The repulsion from the 3 negatively charged phosphates creates high instability when one phosphate leaves, energy is released

Question 7

What harness the energy released during ATP hydrolysis in several ways to perform the three types of cellular work ?

Answer 7

Cell’s proteins

Question 8

What type of reactions do ATP hydrolysis power

Answer 8

endergonic reactions use ATP hydrolysis

Question 9

phosphorylated intermediate, give examples

Answer 9

the recipient of the inorganic phosphate group(covalently bonded)

work movement of motor proteins and shape changes are due to phosphorylation

Question 10

How is ATP regenerated

Answer 10

the coupling of energy-yielding and energy-consuming processes , ADP + P makes ATP + H2O which is endergonic, vice versa for the reverse