4.2 Energy Metabolism

Question 1

Where does the energy to make ATP come from?

Answer 1

Chemical bonds in food molecules

Question 2

In cells, energy can be extracted from food molecules where…

Answer 2

Electrons are shared equally by covalent bonds

Question 3

Examples of food molecules that can be used for energy

Answer 3

Carbon-carcon bonds and
Carbon-Hydrogen bonds
Found in lipids, carbs, AAs and nucleotides

Question 4

Oxygen is the ______, once O is in a covalent bond with carbon or hydrogen, energy _______ be extracted

Answer 4

Ground state

CAN NOT

Question 5

More carbons and more bonds =

Answer 5

More available energy (E)

Question 6

More atoms and electrons bonding =

Answer 6

More energy

Question 7

How do cells extract energy from foods?

Answer 7

Oxidation-reduction chemical reactions

Question 8

Are redox reactions always 100% efficient?

Answer 8

No, some energy is ALWAYS lost as heat

Question 9

Reduction is…

Answer 9

A molecule gaining energy

Question 10

Oxidation is…

Answer 10

When a molecule loses energy

Question 11

Are redox reactions always paired?

Answer 11

Yes, if a molecule gets oxidized, something simultaneously gets reduced

Question 12

NAD+ + Energy –>

Answer 12

NADH

reduction

Question 13

NADH oxidation

Answer 13

NAD+ + Energy

Question 14

OIL RIG

Answer 14

Oxidation is loss (of e-)
Reduction is gain
(of e-)

Question 15

What is NADH doing?

Answer 15

Storing energy

Question 16

All 6 C’s in glucose are..

Answer 16

Oxidized to CO2

Question 17

When glucose is oxidized to CO2..

Answer 17

Energy is released
ADP–>ATP
Oxygen reduced to H2O

Question 18

What percentage of energy is captured to make ATP?

Answer 18

30-40%

Question 19

When does aerobic cellular respiration occur?

Answer 19

When there is adequate oxygen supply (lungs, CV system, and RBCs can keep up with demand)

Question 20

Products of Aerobic cellular respiration

Answer 20

CO2 + H2O

36 ATP / glucose

Question 21

Anaerobic cellular respiration occurs when there is..

Answer 21

Inadequate oxygen

Question 22

Products of anaerobic cellular respiration

Answer 22

Lactic acid

2 ATP / glucose

Question 23

4 Stages of aerobic cellular respiration

Answer 23

1. Glycolysis
2. Acetyl-CoA formation
3. Kreb’s Cycle
4. Electron transport chain and oxidative phosphorylation

Question 24

Start and end of glycolysis

Answer 24

6C Glucose
3C Pyruvate (x2)

Question 25

Energy captured by reduction in glycolysis

Answer 25

2 ATP | 2 NADH

Question 26

What happens if regeneration of NAD+ stops?

Answer 26

Glycolysis stops

Question 27

During pyruvate oxidation, what is pyruvate oxidized to?

Answer 27

Acetyl CoA (Produces 2)

Question 28

Per 1 glucose in pyruvate oxidation.....

Answer 28

- 2 CO2 released by oxidation | - 2 NADH produced by reduction

Question 29

After pyruvate oxidation, there is a...

Answer 29

Decision point!

Question 30

If cell needs ATP after pyruvate oxidation

Answer 30

Acetyl CoA proceeds to step 3: Kreb's Cycle

Question 31

If there is plenty of ATP after Kreb's cycle...

Answer 31

Acetyl CoA goes into long term energy storage (adipose tissue, triglycerides)

Question 32

If you burn fat for energy, you release..

Answer 32

Acetyl CoA

Question 33

Overall effect of Kreb's Cycle

Answer 33

Oxidation of remaining acetyl-coA to CO2 | Reduction of NAD+ to NADH

Question 34

After the Kreb's Cycle, what has the cell made

Answer 34

6 CO2 4 ATP 10 NADH 2 FADH2

Question 35

During ETC and OP, high energy electrons from _____ are used to fuel _______ ion pumps

Answer 35

NADH | H+

Question 36

H+ ion pumps create H+ ion ________, flow of ions used to make ____

Answer 36

Gradient | ATP

Question 37

Oxygen is the ground state in the ETC and OP, meaning that..

Answer 37

Electrons flow down towards it

Question 38

Issue with glycolysis and anaerobic cellular respiration

Answer 38

Regenerating NAD+ from NADH to keep glycolysis running smoothly

Question 39

Without NAD+, glycolysis...

Answer 39

Stops cold (but is usually not a problem since oxygen is around)

Question 40

Solution to NAD+ problem in anaerobic cellular respiration

Answer 40

NADH electrons dropped onto Pyruvate (reduces it), frees up NAD+ to go back and keep glycolysis running

Question 41

Result of reducing pyruvate...

Answer 41

Creates lactate or lactic acid (in animals) | Or yeast / ethanol in plants