Biology Test #5

Question 1

What kinds of energy are important in cells? What about the laws of thermodynamics?

Answer 1

potential energy
kinetic energy
heat energy
First Law of Thermodynamics: Energy can neither be created nor destroyed. It can only change forms.
Second Law of Thermodynamics: Energy systems have tendency to increase their entropy.

Question 2

How do the following store energy: carbon-carbon, ion gradients, electron carriers.

Answer 2

Carbon-carbon bonds: potential energy
Ion gradients: Kinetic energy
Electron Carriers: Kinetic energy

Question 3

Summarize the outcomes of each stage of metabolism.

Answer 3

Digestion: Enzymes in the mouth and stomach, stomach acid and churning break large molecules into subunits.
Glycolysis: Breaking 6 carbon glucose into two 3 carbon pyruvate.
Citric Acid Cycle: Oxidize carbon chains and store electrons in NADH, FADH2
Oxidative Phosphorylation: receiver electrons from carries, creates a proton gradient, powers mass production of ATP

Question 4

What are the inputs and outputs of glycolysis?

Answer 4

Glycolysis
Input:
- 1 glucose
- 2 ATP
Output:
- 2 pyruvate
- 4 ATP
- 2 NADH

Question 5

Track the number of carbons through glycolysis and TCA.

Answer 5

Glycolysis: 6 carbons in: two 3 carbon molecules out
The Citric Acid Cycle: three carbons go in, one is lost, 3 to 2 to 6 to 4

Question 6

Explain how the ETC works.

Answer 6

• electrons from NADH and FADH2 move through 4 complexes
• complexes pump protons to inner membrane space
• proton gradient moved down it gradient and powers ATP synthase

Question 7

Explain how ATP synthase works.

Question 8

Explain why electrons only flow on way down the ETC.

Answer 8

Electrons start with high energy and lose some at each complex. Each complex will only accept an electron at a particular energy level

Question 9

What are the inputs and outputs of the citric acid cycle?

Answer 9

inputs:
1 pyruvate
outputs:
3 CO2
1 ATP
4 NADH
1 FADH2

Question 10

What are the inputs and outputs of light reactions?

Answer 10

Inputs: Sunlight
Outputs: NADPH and ATP

Question 11

What are the inputs and outputs of the Calvin cycle

Answer 11

Inputs:
- 3 CO2
- 9 ATP
- 6 NADPH
Outputs:
- G3P

Question 12

Track the number of carbons through light reactions and Calvin cycle.

Question 13

Why are 2 photosystems required in the chloroplast?

Answer 13

2 photosystems are required because the electrons lose energy and need to be reenergized

Question 14

Describe the events in the reaction center and the path of the electrons through the ETC.

Question 15

What are the three stages of the Calvin cycle.

Answer 15

1. Carbon Fixation
2. Reduction
3. Regeneration

Question 16

How do plants use Calvin cycle products?