Cellular Respiration

Question 1

What is cellular metabolism

Answer 1

the sum of all chemical reactions in a cell

Question 2

Point of cellular respiration?

Answer 2

Convert energy stored in glucose to ATP

Question 3

Order of the three phases?

Answer 3

Glycolysis -> Citric acid cycle -> oxidative phosphorylation

Question 4

Where does Glycolysis occur

Answer 4

In the cytoplasm (anaerobic)

Question 5

What is the point of Glycolysis

Answer 5

Begin oxidation of Glucose

Question 6

First reaction of Glycolysis?

Answer 6

Hexokinase (addition of inorganic Pi from ATP makes glucose more reactive)

Question 7

Third reaction of Glycolysis?

Answer 7

Phosphofructokinase (another ATP required to phosphorylate the sugar)

Question 8

Meaning of phosphorylate?

Answer 8

Introduce a phosphate group into a molecule

Question 9

What happens after phosphofructokinase?

Answer 9

Glucose is split into 2x3C (G3P)

Question 10

Two phases of Glycolysis?

Answer 10

Energy investment (Hexokinase & phosphofructokinase) and energy payoff

Question 11

First step of energy payoff phase?

Answer 11

NADH is produced from NAD+ (organic C has been partially oxidized)

Question 12

The first reactions of the energy payoff phase occur __ times each

Answer 12

two

Question 13

What is substrate level phosphorylation?

Answer 13

When energy for ATP synthesis comes from the dephosphorylating of a substrate (losing P)

Question 14

How many ATP does Glycolysis provide per Glucose?

Answer 14

Two (2 used, 4 produced)

Question 15

How many NADH are produced per Glucose in Glycolysis

Answer 15

two

Question 16

What is the product of Glycolysis?

Answer 16

Pyruvate (3C)

Question 17

What is the site of cellular respiration?

Answer 17

Mitochondria

Question 18

How many times does Glycolysis happen per glucose?

Answer 18

twice

Question 19

Pyruvic acid is _______ into Acetyle CoA by ________ when pyruvate enters the ___________ because otherwise it is ____________.

Answer 19

1. oxidized
2. Coenzyme A
3. mitochondria
4. impermeable

Question 20

How many carbons in acetyl CoA

Answer 20

two

Question 21

Point of Krebs/Citric acid cycle?

Answer 21

Complete oxidation of glucose (CH -> CO2)

Question 22

Where does the Krebs cycle occur?

Answer 22

In the matrix

Question 23

What is FADH2?

Answer 23

Another type of electron carrier (lower energy electrons than NADH)

Question 24

How many times does the Krebs cycle turn per Glucose?

Answer 24

Twice

Question 25

How many ATC are produced by the Krebs cycle?

Answer 25

Two

Question 26

What is the strongest oxidizing agent?

Answer 26

oxygen

Question 27

What happens at the end of the electron transport chain?

Answer 27

Oxygen is reduced (O2 -> H2O)

Question 28

What is Chemiosmosis

Answer 28

Synthesis of ATP using an H+ gradient

Question 29

Where does the energy for chemiosmosis come from (difference btw Photosynthesis and Cell Resp)

Answer 29

In photosynthesis: energy for H+ gradient comes from light (Photophosphorylation) In Cell resp: energy for H+ gradient comes from redox reactions: glucose (oxidative phosphorylation)

Question 30

When does fermentation occur

Answer 30

O2 depleted in environmen

Question 31

What is the point of fermentation?

Answer 31

recycle NAD+ for continued glycolysis in the absence of TEA (oxygen)

Question 32

How many ATP does fermentation produce per glucose?

Answer 32

two

Question 33

How does pyruvates role change during fermentation?

Answer 33

Acts as an electron acceptor to free up NAD+

Question 34

How is pyruvate a "decision point"?

Answer 34

It decides whether or not to enter mitochondria, dependent on presence of O2

Question 35

What happens when there's no sugars available?

Answer 35

Secondary source of nutrients is fats (enter Krebs as 2C acetyl CoA) Tertiary source of nutrients is proteins

Question 36

What are the two inhibitors of Cellular Respiration?

Answer 36

ATP: when there's enough ATP, ATP will bind yo phosphofructokinase and cause a change in shape of the enzyme Citrate: too much acetyl CoA, citrate inhibits PFK