How cells harvest energy- Chapter 7

Question 1

Autotrophs

Answer 1

Produce their own organic molecules (energy) through photosynthesis

Question 2

Heterotrophs

Answer 2

Live on organic compounds produced by other organisims (autotrophs)

Question 3

Cellular respiration

Answer 3

Series of reactions to extract energy from organic molecules

Question 4

Oxidation

Answer 4

Loss of electrons

Question 5

Dehydrogenations

Answer 5

Lost electrons accompanied by protons (a hydrogen atom is lost: 1 electron, 1 proton)

Question 6

Redox reactions

Answer 6

Electrons carry energy from one molecule to another

Question 7

NAD (Nicotinamide adenine dinucleotide)

Answer 7

Electron carrier that accepts 2 electrons and 1 proton to become NADH. Reaction is reversible.

Question 8

Aerobic respiration

Answer 8

Final electron receptor is oxygen (O2)

Question 9

Anaerobic respiration

Answer 9

Final electron acceptor is an inorganic molecule (not oxygen)

Question 10

Fermentation

Answer 10

Final electron acceptor is an organic molecule

Question 11

Aeroic Respiration Reaction

Answer 11

6CO2 + 6H2O → C6H12O6 + 6O2

Question 12

Change in free energy (Delta G)- Aerobic respiration

Answer 12

ΔG= -686kcal/mol of glucose

Question 13

Delta G in a cell

Answer 13

ΔG= -720 kcal/mol

Question 14

Electron carriers

Answer 14

Soluble and membrane-bound carriers that can be easily oxidized and reduced. (Many types used)

Question 15

ATP

Answer 15

Cells use ATP to drive endergonic reactions:
ΔG= -7.3kcal/mol

Question 16

Substrate-level phosphorylation

Answer 16

Transfer phosphate grroup directly to ADP during glycosis

Question 17

Oxidative phosphorylation

Answer 17

ATP synthase uses energy from a proton gradient

Question 18

Pyruvate Kinase

Answer 18

Enzyme involved in substrate-level phosphorylation

Question 19

Glycolysis

Answer 19

Converts 1 glucose to 2 pyruvate

Question 20

Pyruvate oxidation

Answer 20

In presence of oxygen, pyruvate oxidized in mitochondria by multienzyme complex called pyruvate dehydrogenase.

Question 21

Krebs cycle

Answer 21

Oxidizes the acetyl group from pyruvate

Question 22

Regeneration of oxaloacetate

Answer 22

Process of regenerating oxaloacetate in Krebs Cycle.

Question 23

Krebs Cycle

Answer 23

A key metabolic pathway that processes acetyl groups.

Question 24

Energy yield from glucose oxidation

Answer 24

Glucose has been oxidized to 6 CO2, 4 ATP, 10 NADH, and 2 FADH

Question 25

Electron Transport Chain

Answer 25

Series of memebrane-bound electron carriers embedded into inner mitochondrial membrane.

Question 26

Krebs Cycle produces

Answer 26

- Releases CO2 - Reduction of NAD+ and FAD - Production of ATP

Question 27

ETC transfers electrons from _____ to _____

Answer 27

NADH to FADH

Question 28

Chemiosmosis

Answer 28

Process where accumulation of protons in the intermemebrane space drive protons into matrix.

Question 29

Chemiosmosis done via...

Answer 29

Diffusion, primarily through ATP synthase.

Question 30

Bacteria- Theoretical energy yield

Answer 30

32 ATP per glucose Eukaryotes- 30 ATP per glucose

Question 31

Eukaryotes- Theoretical energy yield

Answer 31

30 ATP per glucose

Question 32

Proton movement- NADH

Answer 32

Moves 10 H

Question 33

Proton movement- FADH

Answer 33

Moves 6 H+

Question 34

ATP production per carrier- NADH

Answer 34

Each NADH makes 2.5 ATP

Question 35

ATP production per carrier- FADH

Answer 35

Each FADH makes 1.5 ATP.

Question 36

Feedback inhibtion

Answer 36

Process where end product of metabolic pathway inhibits an earlier step.

Question 37

Phosphofructokinase inhibition

Answer 37

Phosfru. is allosterically inhibited by ATP and citrate.

Question 38

Pyruvate dehydrogenase inhibtion

Answer 38

Pyruvate dehydro. inhibited by high levels of NADH.

Question 39

Citrate synthesis inhibition

Answer 39

Citrate synthetase is inhibited by high levels of ATP

Question 40

Uncoupling of Electron Transport System

Answer 40

Multiple molecules can inhibit the electron transport system by making the membrane 'leaky' to H+ or preventing ATP synthase from producing ATP.

Question 41

Fermentation

Answer 41

Process that uses organic molecules as final electron acceptor

Question 42

Fermentation uses final electron acceptor to...

Answer 42

Regenerate NAD+

Question 43

Methanogens

Answer 43

Organisms that reduce CO2 to CH4 (methane)

Question 44

Sulfur bacteria

Answer 44

Bacteria that reduce inorganic sulfate to hydrogen sulfide

Question 45

Ethanol fermentation

Answer 45

Occurs in yeast producing CO2, ethanol, and NAD+

Question 46

Lactic Acid Fermentation

Answer 46

Occurs in animal cells, where electrons transferred from NADH to pyruvate to produce lactic acid.

Question 47

Deamination

Answer 47

Process that prepares amino acids for energy production by removing amino group.

Question 48

Catabolism of fat

Answer 48

Fats broken down to fatty acids and glycerol

Question 49

Fatty acids in catabolism

Answer 49

Fatty acids converted to acetyl groups by B-oxidation.

Question 50

Evolution of glycolosis

Answer 50

A pathway found in all living organisms that represents an early stage in the evolution of metabolism.