Photosynthesis and Respiration

Question 1

What is ATP?

Answer 1

Adenosine triphosphate is a high energy molecule that has an adenosine molecule attached to three phosphates. The bond to the third phosphate has high energy.

Question 2

What is the ATP-ADP cycle?

Answer 2

A cycle that describe the storage and release of energy by ATP and ADP molecules. When the bond of the thrid phosphate of ATP is broken, energy is released for a cell activity, and a free phosphate and ADP is left. To store energy, the bond is reformed.

Question 3

What is photosynthesis?

Answer 3

A process by which plants use light energy from the sun to make ‘food’, in the high energy glucose molecule.

Question 4

What is the word equation for photosynthesis?

Answer 4

water + carbon dioxide –> glucose + oxygen

(light energy)

Question 5

What is the balanced chemical equation for photosynthesis?

Answer 5

6H20 + 6CO2 –> C6H12O6 + 6O2

Question 6

Describe the light-dependent stage of photosynthesis

Answer 6

In this first stage, occurring in the grana of the chloroplasts, light is absorbed by chlorophyll. This energy is used to split water molecules into hydrogen ions and oxygen. The oxygen is released, and the hydrogen is used in the next phase. Some ATP is formed.

Question 7

Describe the light-independent stage of photosynthesis

Answer 7

Also called carbon fixation, it occurs in the stroma of chloroplasts. Carbon dioxide is combined with the hydrogen ions to form glucose. The ATP from first stage used here.

Question 8

What is cellular respiration?

Answer 8

The break down of glucose to make ATP.

Question 9

What is the word equation for aerobic cellular respiration?

Answer 9

glucose + oxygen –> carbon dioxide + water + ATP

Question 10

What is the balanced chemical equation for aerobic cellular respiration?

Answer 10

C6H12O6 + 6O2 + ADP + P –> 6CO2 + 6H2O + 36ATP

Question 11

What occurs in glycolysis, the first stage of aerobic respiration?

Answer 11

In the cytoplasm, glucose is split into two pyruvate molecules, also producing 2ATP and 2NADH (a coenzyme)

Question 12

What occurs in the kreb’s cycle, the second stage of aerobic respiration?

Answer 12

In the matrix of the mitochondria, the oxygen and carbon from the pyruvate is released, hydrogen is left in NADH, 2ATP produced

Question 13

What occurs in the electron transport chain? (3rd stage aerobic respiration)

Answer 13

Occurs on the cristae (folds within mitochondria), hydrogen passed along, ATP is produced in large amounts, oxygen forms water with hydrogen.

Question 14

What are the two types of anaerobic cellular respiration?

Answer 14

Alcohol fermentation, and lactic acid fermentation.

Question 15

What are the equations for alcohol fermentation?

Answer 15

Glucose –> ethanol + carbon dioxide + ATP

C6H12O6 –> 2CH3CH2OH + 2CO2 + 2ATP

Question 16

What are the equations for lactic acid fermentation?

Answer 16

Glucose –> lactic acid + ATP

C6H12O6 –> 2CH3CH(OH)COOH + 2ATP

Question 17

Why does lactic acid fermentation occur?

Answer 17

It occurs when an organism cannot get enough oxygen to use aerobic respiration. Occurs during strenuous exercise.

Question 18

What happens to the lactic acid once exercise is done?

Answer 18

The lactic acid is converted to pyruvate, which is used in aerobic respiration.

Question 19

Why are photosynthesis and respiration not the reverse of each other?

Answer 19

Even though the products and reactants are reversed, the processes involve lots of different chemical reactions.