Structure and Function of ATP (Q1)

Question 1

Components of adenosine triphosphate (ATP)

Answer 1

1. Chain of three phosphate groups
2. Pentose sugar ribose/ 5-carbon sugar
3. Nitrogenous base (adenine)

Question 2

Combining ribose sugar and adenine results in a nucleoside called _______.

Answer 2

Adenosine

Question 3

Functions of ATP

Answer 3

1. Mediates energy coupling
2. Acts as immediate energy source for cellular work
3. Used in making RNA

Question 4

How does energy coupling help in cell work?

Answer 4

Energy coupling allows cells to transfer energy from one reaction to another wherein cells use an exergonic process to drive an endergonic reaction.

Question 5

Kinds of work of a cell

Answer 5

1. Chemical work
2. Transport work
3. Mechanical work

Question 6

Example of chemical work

Answer 6

Synthesis of polymers from monomers (Endergonic reaction)

Question 7

Example of transport work

Answer 7

Pumping of substances across membranes against spontaneous movement

Question 8

Example of mechanical work

Answer 8

Beating of cilia, muscle contraction

Question 9

Why can ATP also produce RNA?

Answer 9

RNA is composed of ribose sugar attached to nitrogenous bases and phosphate groups.

Question 10

Bond connecting ribose sugar and phosphate group

Answer 10

Phosphoester bonds

Question 11

Bond connecting phosphate groups to each other

Answer 11

Phosphoanhydride bonds

Question 12

Process that uses water to break down the bond between phosphate groups

Answer 12

Hydrolysis

Question 13

Where is the energy stored in ATP?

Answer 13

Between the bonds connecting the phosphate groups together

Question 14

Why are phosphoanhydride bonds unstable?

Answer 14

Due to the electrostatic repulsion between the negative charges in the oxygen atoms of the three phosphate groups

Question 15

What kind of energy is stored in the bonds between phosphate groups?

Answer 15

Potential chemical energy

Question 16

How is the stored potential energy between the phosphate group bonds released?

Answer 16

By releasing one phosphate group

Question 17

Is ATP hydrolysis exergonic or endergonic?

Answer 17

Exergonic

Question 18

How much energy does hydrolysis release?

Answer 18

-7.3 kcal/mol or -30.5 kJ/mol

Question 19

What enzyme catalyzes the hydrolysis of the bond between the second and third phosphate group in ATP?

Answer 19

ATPase

Question 20

Products of ATP hydrolysis

Answer 20

1. Adenosine diphosphate (ADP)
2. Inorganic phosphate (HOPO3 ^-2)
3. Energy

Question 21

Write the chemical equation for ATP hydrolysis.

Answer 21

ATP + H20 –> ADP + Pi + Energy

Question 22

Where does the release of energy come from?

Answer 22

From the chemical change of the system state of lower free energy

Question 23

ATP hydrolysis leads to changes in protein shape and its binding ability with another molecule. True or False?

Answer 23

True

Question 24

Process of converting ADP to ATP

Answer 24

Phosphorylation

Question 25

Process of converting ATP to ADP

Answer 25

Dephosphorylation

Question 26

Is the hydrolysis of ATP to ADP reversible?

Answer 26

Yes

Question 27

Is the hydrolysis of ATP spontaneous or non-spontaneous?

Answer 27

It is spontaneous because there is a release of free energy.