What Is ATP?

Question 1

Describe ATP

Answer 1

Adenosine triphosphate. When the energy is released from glucose during cellular respiration, it is stored in ATP molecules to be used by the cell later. It is a nucleotide (sugar, phosphate, and base)

Question 2

Describe the functions of ATP

Answer 2

Major energy carrier to provide energy to endothermic reactions, monomer for DNA and RNA, regulates many biochemical pathways

Question 3

Show a diagram of ATP

Question 4

By what process does ATP give us energy?

Answer 4

ATP - ADP cycle

Question 5

Describe the ATP - ADP cycle

Answer 5

ATP stores energy in the bonds between phosphate groups. When the third phosphate’s bond is broken (high energy bond) by a hydrolysis reaction, ADP is formed and free energy is released for the cell to use. The equation will move in both directions depending on the needs of the cell (forward when the cell needs energy, reverse when cell stores energy)

Question 6

What enzyme is present in the hydrolysis of ATP into ADP?

Answer 6

ATPase

Question 7

Give the equation for the hydrolysis of ATP into ADP

Answer 7

A-P-P-P + H2O <-(ATPase)-> A-P-P + Pi + energy

Question 8

What enzyme is present in the synthesis of ATP from ADP?

Answer 8

ATP synthase

Question 9

How is ATP made?

Answer 9

By adding phosphate back to an ADP molecule, the cell can replace its energy molecules. This process requires an input of energy (which comes from the breaking down of glucose in cellular respiration and storage in its bond)

Question 10

Give the equation for the synthesis of ATP from ADP

Answer 10

A-P-P + Pi + energy <-ATP synthase-> A-P-P-P + H2O

Question 11

Where is ATP made?

Answer 11

In the cytoplasm by glycolysis, in mitochondria by cellular respiration, in chloroplasts by photosynthesis

Question 12

Where is ATP consumed?

Answer 12

Assembly of amino acids into proteins, nucleotides into DNA and RNA, and polysaccharides; synthesis of fats; active transport; supplies energy for muscles, cilia, and flagella

Question 13

By what processes do cells make ATP?

Answer 13

Substrate-level phosphorylation and oxidative phosphorylation (chemiosmosis)

Question 14

What is the ultimate goal of cellular respiration?

Answer 14

To capture as much available free energy as possible in the ATP

Question 15

Describe substrate-level phosphorylation

Answer 15

Enzyme-catalyzed anaerobic process which occurs in glycolysis and Kreb’s cycle. A phosphate-containing group (phosphoenol pyruvate) transfers a phosphate group directly to ADP to form ATP

Question 16

Give the equation for substrate-level phosphorylation

Answer 16

PE-P + A-P-P <-enzymes-> pyruvate + A-P-P-P

The enzymes are phosphoglycerate kinase and pyruvate kinase

Question 17

Describe oxidative phosphorylation (chemiosmosis)

Answer 17

Highly efficient aerobic process which occurs in the electron transport chain. It is the osmosis of protons

Question 18

Give the first step of oxidative phosphorylation

Answer 18

NADH and FADH2 molecules are reduced from the glucose molecule from the first three stages of cellular respiration. They enter the electron transport chain where they are oxidized, transferring electrons to molecules near the beginning of the ETC

Question 19

Give the second step of oxidative phosphorylation

Answer 19

The H ions on the inside of the membrane are moved to the outside of the membrane using a proton pump. A hydrogen ion gradient is formed where there is a high concentration of H+ in the ECF and a low concentration of H+ in the ICF

Question 20

Give the third step of oxidative phosphorylation

Answer 20

This concentration gradient creates an electrochemical gradient (more positive on the outside) which creates a force that moves protons through special proton channels. As the protons move through the pump, ATP synthase uses this proton motive force to phosphorylate ADP to ATP

Question 21

Give a simple three-step explanation of chemiosmosis

Answer 21

NADH is oxidated and the H+ ions are pumped into the ECF. Huge H+ gradient is used to drive the proton pumps. As H+ ions are sucked through the pump, it drives the production of ATP with the aid of ATP synthase

Question 22

Read pages 141-145 of the textbook