W:3 Biochemistry - Energy producing catabolism

Question 1

Where is the direction of the H+ in active transport?

Answer 1

Out of the mitochondrial matrix into the intermembrane space

Question 2

NADH/FADH2 generate more H+, thus more ATP than NADH/FADH2.

Answer 2

NADH, FADH2

Question 3

What is the role of brown and beige fat and how do they process H+ differently than the regular ETC?

Answer 3

They generate energy in the form of heat.

They have UCP that dissipates H+ gradient without ATP formation.

Question 4

What are metabolites that provide energy? (4 energy carriers)

Answer 4

ATP, NADH, FADH2, GTP

Question 5

Where does TCA/Kreb cycle take place?

Answer 5

Mitochondria

Question 6

What and how many high energy products are made in once cycle of the TCA cycle?

Answer 6

3 NADH
1 FADH2
1GTP

Question 7

What is generated in mitochondrial beta oxidation of FA?

Answer 7

acetyl-CoA + FADH2 + NADH

Every reaction: FA is 2 carbons shorter

Question 8

FA is a stable molecule so need to by activated by ____ using ___.

Answer 8

Acyl-CoA, ATP

Question 9

Acyl-CoA is attached to “shuttle” ______ to be transported from _____ to _____.

Answer 9

Carnitine, cytoplasm, mitochondria

patients with no carnitine have trouble metabolizing fat; enzymes for beta oxidation are all in mitochondria

Question 10

Where do FA longer than 22 carbons get preliminary processing?

Answer 10

Peroxisomes

Question 11

Where are ketone bodies made? Degraded?

Answer 11

Made in the hepatocytes (liver)

Degraded in mitochondria of cells EXCEPT liver (can’t degrade because they don’t have an enzyme)

Question 12

What are the three ketone bodies? How many carbons?

Answer 12

Acetoacetate
3-Hydroxybutyrate
Acetone
(4 carbons)

Question 13

What is byproduct of ketone body metabolism (ketoacidosis)? (what you smell in the breath)

Answer 13

Acetone (no energy; occurs when there’s too much sugar for prolonged time)

Question 14

What important metabolites are produced in ketolysis?

Answer 14

Acetyl-CoA, NADH

Question 15

What is generated from conversion of pyruvate –> Acetyl-CoA and where does it happen?

Answer 15

NADH, mitochondria

Question 16

Where does ethanol catabolism occur and what does it generate?

Answer 16

Cytosol, mitochondria of hepatocytes; each make 1 NADH (2 total), acetyl-CoA

Question 17

What enzymes carry out the oxidation reactions?

Answer 17

dehydrogenases

Question 18

Where does glycolysis occur?

Answer 18

Cytosol

Question 19

What are net products of glycolysis?

Answer 19

2 ATP (net)
2 NADH
2 Pyruvates

Question 20

What happens if the mitochondria is not taking up the products of glycolysis? How do you go around it?

Answer 20

They will build up, halting glycolysis. Lactic acid metabolism

Question 21

What process does RBC use to maintain source of ATP?

Answer 21

Glycolysis

Question 22

Ketone bodies are made in ___ but catabolized in ___.

Answer 22

Liver, cells other than the liver

Question 23

In anaerobic glycolysis, ___ and ___ are consumed and ___ is formed.

Answer 23

NADH, pyruvate, lactic acid

Question 24

What is the significance of PPP in cell energy metabolism?

Answer 24

Let sugars with other than C-6 enter glycolysis (ribose)

Question 25

Where does PPP take place?

Answer 25

Cytosol

Question 26

What are ways acetyl-CoA can be produced?

Answer 26

Beta-oxidation
Ketolysis
Decarboxylation of pyruvate
Ethanol metabolism

Question 27

RBC lacks mitochondria so they only rely on ____ to produce ATP.

Answer 27

glycolysis

Question 28

Amino acid catabolism: examples of molecules that can enter various cycles are:

Answer 28

Ala –> pyruvate
Glu –> alpha KG
Two amino groups of Gln –> TCA cycle intermediate

Question 29

Liver makes and breaks down ketone bodies. T/F

Answer 29

F: Liver makes ketone bodies during fasting but hepatocytes don’t catabolize them

Question 30

Erythrocytes lack ___ and have little ___.

Answer 30

Mitochondria, glycogen

Question 31

Glycolysis generates 2, 3-BPG. Why is this significant in erythrocytes?

Answer 31

3-BPG facilitates release of O2 from Hb A (reduces affinity of O2)

Question 32

3-BPG increases/decreases during chronic hypoxia, anemia, or pregnancy

Answer 32

Increases; meaning more O2 release in tissues

Question 33

What glucose transporter does skeletal muscle use? Is this insulin dependent?

Answer 33

GLUT4; yes

Question 34

What is the role of myoglobin in muscle?

Answer 34

Capture the oxygen that hemoglobin released outside the cell; a lot of myoglobin in fibers with a lot of aerobic metabolism

Question 35

What is the function of creatine-phosphate system?

Answer 35

Creating “buffer” that increases pool of readily available ATP

Creatine takes P from ATP to generate ADP. The Creatine-P is a ready reserve of ATP. ATP inhibits pathways that create more ATP at equilibrium. Creatine-P “hides” ATP so that the energy building cycles continue

Question 36

What sources of energy do cardiomyocytes use?

Answer 36

EVERYTHING: FA» glc, ketone bodies, glycerol lactate (to make pyruvate)

Make sure metabolism will not exhaust ATP in cell

Question 37

Which tissues use creatine-P?

Answer 37

Skeletal, heart, neurons

Question 38

Are cardiomyocytes insulin dependent?

Answer 38

No; uptake happens with or without insulin

Question 39

The main source of energy for neurons is ______ from ______.

Answer 39

Glucose, blood

Question 40

What glucose transporter do neurons use? Is this insulin dependent?

Answer 40

GLUT1; no, uptake is constant

Question 41

Why is there no FA oxidation in neurons? Two reasons.

Answer 41

1) NADH is more efficient than FADH2
2) FAO may generate ROS

Because their mitochondria don’t carry a lot of the enzymes for FAO. This is because of efficiency. NADH generates more ATP per O2 compared to FADH2. (not because of diffusion issues with BBB)

Neurons don’t handle oxygen species as well.

Question 42

Where does PPP take place?

Answer 42

cytosol

Question 43

What pathway generates ribose for nucleotide? What happens when ribose is activated?

Answer 43

PPP (ribose 5-P);

ribose –> PRPP

Question 44

What are the two ways nucleotides are made?

Answer 44

1) De Novo synthesis

2) Purine Salvage pathway

Question 45

What enzyme is responsible for the purine salvage pathway? What are its two substrates?

Answer 45

HGPRT (hypoxanthine guanine phosphoribosyl transferase);

hypoxanthine, guanine

Question 46

Gout, a _____ disease, is caused by accumulation of _______ in the body (joints) due to protein ______ deficiency in the purine salvage pathway.

Answer 46

X-linked, uric acid, HGPRT

Question 47

What is a possible treatment for gout?

Answer 47

Decrease uric acid by inhibiting xanthine with drug

Question 48

SCID (sever combined immunodeficiency), a _____ _____ disease, is caused by inability to degrade ________ from _______ deficiency.

Answer 48

Autosomal recessive, adenosine, ADA

Question 49

How does ADA deficiency cause SCID?

Answer 49

ADA deficiency means inability to break down adenosine in the body (ADP, ATP). Accumulation means no more synthesis, no new DNA, no lymphocytes (B- cells, T-cells)

Question 50

What is the treatment for SCID?

Answer 50

Gene therapy

Question 51

Skeletal cells: GLUT#, insulin-_____

Neurons: GLUT#, insulin-______

Which cells are insulin independent? (uptake glc constantly without regulation; high demand)

Answer 51

(4, dependent)

(1, independent)

Neurons and cardiomyocytes (heart)