Cellular Respiration and Photosynthesis

Question 1

Fermentation

Answer 1

a partial degradation of sugars or other organic fuel that occurs without the use of oxygen

Question 2

aerobic respiration

Answer 2

oxygen is consumed as a reactant along with the organic fuel (aerobic is from the Greek aer, air, and bios, life).

Question 3

oxidation (chemistry)

Answer 3

The loss of electrons

Question 4

reduction (chemistry)

Answer 4

The addition of electrons

Question 5

reducing agent

Answer 5

the electron donor

Question 6

oxidizing agent

Answer 6

the electron receiver

Question 7

NAD+

Answer 7

nicotinamide adenine dinucleotide
- a derivative of the vitamin niacin
- an electron acceptor than carrier (NADH)

Question 8

Where does glycolysis take place

Answer 8

The cytosol

Question 9

Where does the citric acid cycle and oxidative phosphorylation take place?

Answer 9

The mitochondria

Question 10

Glycolysis

Answer 10

“sugar splitting”

Glucose (six-carbon sugar) is split into two three carbon-sugars, which are then oxidized and their atoms rearranged into pyruvate

Question 11

What are the two phases of glycolysis?

Answer 11

Energy investment - cell spends ATP

Energy payoff - Cell gains ATP via substrate-level phosphorylation and NAD+ is reduced to NADH by electrons released from the oxidation of glucose

NET GAIN from 1 glucose = 2ATP + 2NADH

Question 12

Cytochromes

Answer 12

An iron-containing protein that is a component of election transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells

Question 13

Does the election transport chain make ATP directly?

Answer 13

No, it eases the fall of electrons from food to oxygen, breaking what would be a large free-energy drop into a series of smaller steps

Question 14

chemiosmosis

Answer 14

chemiosmosis is an energy-coupling mechanism that uses energy stored in the form of an H+ gradient across a membrane to drive cellular work.
-done by ATP synthase in mitochondria
-

Question 15

ATP synthase

Answer 15

the enzyme that makes ATP from ADP and inorganic phosphate

Question 16

How does the mitochondrion maintain and generate the H+ gradient?

Answer 16

The electron chain

Question 17

Where does most of the energy from glycolysis and the citric acid cycle go?

Answer 17

NADH and FADH2, which is later released in oxidative phosphorylation, where most ATP is produced

Question 18

Proton-motive force

Answer 18

The potential energy stored in the form of a proton electrochemical gradient, generated by the pumping of hydrogen ions (H+) across a biological membrane during chemiosmosis

Question 19

What is the overall goal of cellular respiration?

Answer 19

Harvesting the energy of glucose for ATP synthesis

Question 20

How much energy is released from the total oxidation of one mole of glucose?

Answer 20

2870 kJ of energy is released

Question 21

Location, reactants, and products of the Light independant Reaction

Answer 21

Calvin Cycle
Takes place in the chloroplast stoma
- Uses CO2 x 6 and NADPH x 12
- Produces G3P x 2

Question 22

Location, reactants, and products of the Light Dependant reaction

Answer 22

Mostly takes place in the thylakoid space
- Uses H2O x 12
- Produces ATP and NADPH x 12

Produces O2 x 6 as a “useless” byproduct

Question 23

Photosystem II (PSII)

Answer 23

First Protein complex in the Z-scheme
- Takes electrons released from the oxygen evolving complex and gets “excited” by photons, then passes the electrons down the electron transport chain to cytochrome

Question 24

Photosystem I (PS1)

Answer 24

Third protein in the Z-scheme
Receives electrons from the cytochrome complex and gets excited by photons
- Creates NADPH

Question 25

Cytochrome

Answer 25

The second protein complex in the Z-scheme
- Pumps protons into the thylakoid space to create a concentration gradient, forcing H+ through ATP synthase to generate ATP
- Passes electrons to PS1

Question 26

Oxygen Evolving Complex (OEC)

Question 27

RuBisCO

Answer 27

Performs both carboxylation and oxygenation

A carboxylase
● An oxygenase (~1000:1 CO2:O2)
● The most abundant enzyme on planet Earth
● A huge enzyme: composed of 16 subunits in plants (8 + 8) > 5 MDa
● A very slow enzyme: fixing only 3 molecules of CO2 per second

Question 28

RuBP

Answer 28

Ribulose 1,5 bisphosphate

The starting and ending protein in the Calvin Cycle (light independent)

Question 29

G3P

Answer 29

Glyceraldehyde 3-phosphate
AKA: Triose phosphate AKA: PGAL

THE PRODUCT OF THE CALVIN CYCLE
(gets converted to glucose and other carbohydrates, or thrown directly into the citric acid cycle)

Question 30

What are the main stages of the Calvin Cycle?

Answer 30

1. Fixation
   - Turns RuBP into PGA
   - Uses up CO2 and ATP
2. Reduction
   - Turns PGA into G3P
   - Uses NADPH
3. Regeneration
   - Remaining G3P is used to regenerate RuBP
   - Uses ATP

Question 31

How many G3Ps get to leave the Calvin cycle?

Answer 31

1

The other five are used to regenerate the original Ribulose bisphospates

Question 32

What are the three stages of cellular respiration

Answer 32

1. Glycolysis
2. The Kreb’s Cycle (citric acid cycle)
3. Electron transport Chain

Question 33

How much ATP and NADH does glycolysis create? (Overall)

Answer 33

-2 ATP + 4 ATP = 2 ATP
2 NADH

Question 34

How much ATP, NADH, and FADH2 does the Kreb’s cycle create? (one molecule of glucose)

Answer 34

2 ATP
6 NADH
2 FADH2

Question 35

How much ATP does oxidative phophalization create?

Answer 35

34 ATP (at best)

Question 36

phophofructokinase 1 (PFK-1)

Answer 36

Enzyme used in glycolysis, converting F6P to F1,6BP

Regulates glycolysis, therefore the rest of cellular respiration and ATP production
- Inhibited by ATP and citrate
- Stimulated by AMP (adenine monophosphate)