Lecture 14

Question 1

What is intermediary Metabolism

Answer 1

the biochemical reactions that provide cells with energy for intermediate use, reducing power for anabolic reactions, and metabolites for biosynthesis

Question 2

How does intermediary metabolism use energy for immediate use

Answer 2

Glycolysis, kreb cycle, ETS
products: ATP and reduced coenzymes (NADH And FADH2

Question 3

How does intermediary metabolism use reducing power for anabolic reactions

Answer 3

nicotinamide adenine dinucleotide phosphate (NADPH)

Question 4

How does intermediary metabolism use metabolites for biosynthesis

Answer 4

nucleotides, amino acids, glucose, fatty acids, etc

Question 5

What is the order of the catabolic pathway

Answer 5

Glucose –> G6P–> FBP–> Pyruvate–> TCA/Krebs/Citric Acid Cycle (8 steps) –> ETC (ATP)

Question 6

What is the order of the Anabolic Pathway

Answer 6

Glucose–> G6P–> NADP+ –> NADPH, CO2–> Ribulose-5-Phosphate –> Glycolysis

Question 7

Glycolysis and Pentose Phosphate Pathway

Answer 7

Both take place in the cytosol
skeletal muscle has no enzymes for PPP pathway

Question 8

What is the importance of PPP in cells

Answer 8

1. Provides Ribulose-5-phosphate for Nucleic Acid Biosynthesis
2. Provides NADPH the reduced coenzyme for anabolism
3. Reduces Oxidative Stress

Question 9

How does PPP reduce oxidative stress

Answer 9

a. neutralizing Reactive Oxygen Intermediates (O2, H2O2) (ROI contribute to Inflammation and Carcinogensis)
b. regenerates reduced glutathione, a powerful antioxidant in cells

Question 10

What is the major pathway of glycolysis

Answer 10

Embden-Meyerhof pathway

Question 11

How is glucose brought into the cell

Answer 11

GluT1

Question 12

What are the 3 outcomes of Glycolysis

Answer 12

1. 2 molecules of Pyruvic acid
   NAD+ are reduced to NADH2
2. 2 molecules of ATP are used and 4 ATP produced by substrate level (NET 2ATP)
3. proceeds anaerobically

Question 13

Which steps in glycolysis are thermodynamically irreversible

Answer 13

1, 3, (investment)
10 (payoff)

Question 14

What process of Glycolysis is critical

Answer 14

recycling of Coenzyme 2NADH2-> 2NAD+

Question 15

What does the reduction of pyruvic acid do

Answer 15

permits redox balance to be maintained without O2

Question 16

How does pyruvic acid get catalyzed to Lactic acid

Answer 16

Lactate dehydrogenase (LDH)

Question 17

What is the net yield of ATP, per molecule of glucose after glycolysis

Answer 17

2 ATP
3 ATP if glycogen is used

Question 18

Describe Glycogenolysis

Answer 18

catalyzed by glycogen phosphorylase
yields G-1-P

Question 19

what is the connecting link between glycolysis and TCA

Answer 19

Pyruvate Dehydrogenase Complex (PDC)
multienzyme complex

Question 20

where does pyruvate go

Answer 20

transported across outer and inner mito. matrix

Question 21

Where is Pyruvate Dehydrogenase Complex located

Answer 21

mitochondrial matrix

Question 22

What does PDC do

Answer 22

catalyzes the decarboxylation of Pyruvic acid
energy released is used to reduce NAD+ to NADH

Question 23

What is the major reactions of the Krebs cycle
Describe the use of tricarboxylic acid TCA

Answer 23

tricarboxylic acid (TCA) reduces coenzymes NAD+ and FAD to NADH and FADH2

Question 24

Describe the chemical composition of TCA

Answer 24

amphibolic
Energy is consumed and produced
Catabolic part –> Acetyl CoA oxidized to CO2 + energy
Synthesizes ATP by substrate level phosphorylation

Question 25

What is the Anabolic part of TCA cycle

Answer 25

TCA intermediates are used as precursors for biosynthesis of complex organic molecules like amino acids, lipids, and nucleotides

Question 26

What do the three complexes of the ETC do

Answer 26

capture energy from electrons carried by NADH in mitochondrial matrix energy released used to pump protons into intermembrane space

Question 27

Where is succinate dehydrogenase located

Answer 27

inner mitochondrial membrane part of Complex II

Question 28

What are essential cofactors of ETC

Answer 28

Fe-S clusters accept and forward electron to Ubiquinone and Cytochrome c

Question 29

what are the mobile electron carries in the ETC

Answer 29

ubiquinone and Cytochrome C

Question 30

What complex in ETC in cytochrome oxidase

Answer 30

complex IV

Question 31

What is the ATP outcome of NADH and FADH2

Answer 31

NADH: 2.5 ATPs FADH2: 1.5 ATPs

Question 32

What is P/O

Answer 32

number of phosphates incorporated to make ATP for each O2 reduced to water ratio can be completely coupled or uncoupledWh

Question 33

at does uncoupled protein 1 do (UCP1)

Answer 33

opposes ATP production Energy is released as heat

Question 34

What are F0 and F1

Answer 34

components of ATP synthase that are biological turbines for synthesizing ATP

Question 35

What is the target of some inhibitors of respiratory system

Answer 35

Krebs cycle

Question 36

What is Rotenone

Answer 36

potent insecticide that inhibits electron transfer from ubiquinone (coenzyme Q) to cytochrome c. (inhibits complex I of ETS)

Question 37

what is Oligomycin

Answer 37

natural bacterial toxin that blocks mitochondrial F1F0 ATP synthase (Complex IV). Uncouples ETS from oxidative phosphylation

Question 38

What is 2,4-Dinitrophenol

Answer 38

inhibits ATP production by shuttling protons across the inner mitochondrial membrane

Question 39

What is potassium cyanide

Answer 39

Reversibly binds to the ferric ions (Complex IV) and effectively blocks the reduction of oxygen to water