Exam #5

Question 1

What’s the difference between a competitive inhibitor and a noncompetitive inhibitor?

Answer 1

A competitive inhibitor actively competes with the substrate to bind to the active site of the enzyme.

The noncompetitive inhibitor binds to a different location on the enzyme but it distorts the shape of the active site, decreasing the chances the substrate can bind.

Question 2

Draw out what a competitive inhibitor, noncompetitive inhibitor, and uninhibited enzyme curve would look like

Question 3

Explain how to calculate Vmax and Km. Explain what they tell you about the graph

Question 4

What are the major parts of glucose metabolism?

Answer 4

Glycolysis, citric acid cycle, ETC, ATP synthesis

Question 5

What’s the difference between reduction and oxidation?

Answer 5

OIL RIG

Question 6

What are the major steps of glycolysis?

Question 7

What happens to glycolysis when there isn’t oxygen available?

Question 8

What are the steps of the citric acid cycle (TCA)?

Question 9

What are the steps of the ETC? Be sure to explain the H+ gradient

Question 10

How does the ATP synthase work in cellular repsiration?

Question 11

What are the pH and ion charge differences inside vs. outside of the mitochondrial membrane? How does this affect the H+ gradient?

Question 12

What is the significance of the H+ gradient in the mitochondria? What would happen if it is swapped or changed?

Question 13

In general terms, how does the body regulate our blood glucose levels?

Question 14

What is the difference between glycolysis and gluconeogenesis regulation?

Question 15

What is phosphofructokinase (PFK)? What kind of regluation is it an example of?

Question 16

Why is adrenaline important? What does it do to the body?

Question 17

How does the body use glycogen to regulate blood glucose levels?

Question 18

How do plants use starch as a glycogen?

Answer 18

Starch is a storage form of sugars in plants. They use it for cell respiration until they can use photosynthesis.

Question 19

What is photosynthesis? Where does it occur? What does it need and what does it release?

Answer 19

Photosynthesis is a series of light reactions to create organic molecules from CO2. It occurs in the chloroplasts, requires CO2 and electron from H2O, releases O2 as waste, requires energy (sun) and oxidizing agent (NADP+), and generates ATP and NADPH to drive carbon fixation (Calvin cycle)

Question 20

What is the difference between the light reactions and the dark reactions? Location too

Answer 20

The light reaction happens in the thylakoid membrane. The light is converted into electrons that move from a high energy state to a lower energy state (they’re more comfortable) this helps pump the H+ gradient from in the stroma to the thylakoid lumen (higher [H+] inside than outside)

The dark reaction (light-independent) is the Calvin cycle.

Question 21

How are photosystems 1 and 2 connected? What is their purpose?

Answer 21

Photosystem 2 is used first and it takes its excited electrons that are excited because they are hit by light and then given to an acceptor molecule to help create a [H+] gradient (pumps H+ out). Then photosystem 1 is hit by light and the excited electrons in that photosystem can then reduces NADP+ to form NADPH. After PS1 gets rid of its electron, it wants a new electron, and it can get it from PS2. This [H+] gradient is then used to activate the ATP synthase :)

Question 22

How does the ETC in photosynthesis work?

Answer 22

The ETC occurs in the thylakoid membrane. It includes light systems 1 and 2, cytochrome complex, ferredoxin (Fd), NADP reductase, and ATP synthase.

Question 23

What are the steps of the Calvin cycle?

Answer 23

It goes around the cycle twice: Rubisco takes in 6 CO2, which splits to create 12 PGA, then 12 ATP are dephosphorylated, and the extra phosphate goes to the PGA to create 12 BPG. 12 NADPH is then oxidated and the extra Hs go on to make 12 G3P. 2 of those G3P are saved to make glucose. The other 10 G3P are regenerated through the phosphorylation of ATP to create 6 RuBP to start the cycle over again.

Question 24

What’s the difference between the photorespiration in C3 and D4 plants?

Answer 24

Both plants have Rubisco. In the presence of high oxygen, it goes through an inefficient pathway to make more CO2

Question 25

How does C4 adapt to increase CO2 levels?

Answer 25

It uses PEP and CO2 to make oxaloacetate, which is then oxidized to form malate. That is then shuttled to the bundle-sheath cell. Here, the CO2 is released and concentrated so Rubisco can fix to G3P

Question 26

Where do the following occur in the mitochondria: glycolysis, fermentation, TCA cycle, and oxidative phosphorylation

Answer 26

Glycolysis: cytosol Fermentation: cytosol TCA cycle: matrix Oxidative phosphorylation: between the intermembrane space and matrix

Question 27

Identify the cytosol, outer membrane, inner membrane with cristae, intermembrane space, matrix

Answer 27

See an image

Question 28

How does the ATP synthase work in photosynthesis?

Answer 28

The H+ gradient goes from the thylakoid space to the stroma. As the protons move through the ATP synthase "machine", the ADP is then phosphorylated to create ATP that is then used in the Calvin cycle, not for general consumption.

Question 29

What happens in the light-dependent reactions?

Answer 29

The light reaction happens in the thylakoid membrane. The light is converted into electrons that move from a high energy state to a lower energy state (they're more comfortable) this helps pump the H+ gradient from the stroma to the thylakoid lumen (higher [H+] inside than outside). This [H+] gradient

Question 30

What is glycogen?

Answer 30

A branched chain of glucose molecules held together by covalent glycosidic bonds. It serves as a quick storage form of glucose in the liver and muscles.