mid term

Question 1

PKF in glycolysis serves to,,,

Answer 1

generate energy when energy levels are low

Question 2

PFK in gluconeogenesis serves to..

Answer 2

store energy when energy levels are high

Question 3

phosphofructokinase

Answer 3

Key regulatory site of glycolysis and gluconeogenesis

• In glycolysis- pfk is inhibited by high nrg (ATP and citrate), activated by low energy (ADP, AMP)
• gluconeogenesis - activated by ATP citrate, inhibited by ADP, AMP

Question 4

Glucose serves as major fuel for energy in most organisms (3)

Answer 4

• can be used as a source of ATP
• can be used to supply th cell w/ AA, mucleotides, FA, and other metabolic intermediates
• can be stored as glycogen or starch

Question 5

glycolysis

Answer 5

-degradation of glucose (C6) to 2 molecules of pyruvate (C3)

Question 6

gluconeogenesis

Answer 6

• process of building glucose from smaller metabolited (pyruvate)
• uses most of the same enzymes in glycolysis (reversible)

Question 7

synthases

Answer 7

catalyze condensation rxns WITH OUT requirement for nucleoside triphosphates **doesn’t need atp

Question 8

synthetases

Answer 8

catalyze condensation rxn that DO use nucleoside triphosphates (succinyl-CoA synthetase)

Question 9

Ligases

Answer 9

Catalyze condensation rxns in which 2 atoms are joined together using ATP

Question 10

Lyases

Answer 10

Catalyze the cleavage with elecronic rearrangements (PDH- COMPLEX)

Question 11

Kinase

Answer 11

-Transfer phosphoryl groups
ATP is involved to put phosphate on molecule
(opposite of phosphatase)

Question 12

phosphatase

Answer 12

-removal of a phosphoryl group from a phosphate ester

Opposite of Kinase

Question 13

allosteric control

Answer 13

Multi unit only
Activator binds and converts the enzyme to the more active R-state

Inhibitor binds and converts the enzyme to the less active T-state

Question 14

phosphofructokinase regulation

Answer 14

• *feed back control
• PFK allosteric enzyme with several regulatory sites
• ATP (inhibitor) binds to PFK and lowers its affinity for Frc-6-P
• ADP (activator) relieves this inhibition by binding PFK and raising its affinity for Frc-6-P

Question 15

where is ATP used in the prep phase of glycolysis?

Answer 15

Step 1 (Glucose to glu-6-p)band Step 3 ( fru 6-P to fru 1,6, bis phospante)

Question 16

What does the magnesium group do? (Mg2+)

Answer 16

-Mg2+ stabilize the phosphate

Mg is a positive ion, helps ADP pull off phosphate

Question 17

Isocitrate dehydrogenase

Answer 17

• RDS
• Co2 loss
• Allosteric enzyme which is activated by ADP (low energy nrg) and inihibited by ATP and NADH (high energy)
• can affect glycolysis with a build of citrate affecting PFK

Question 18

Rate limiting step in TCA

Answer 18

Isocitrate dehydrogenase

Isocitrate to aketoglutarate (NADP–> NADPH)

Question 19

Main purpose of TCA cycle is?

Answer 19

produce energy

Question 20

MEtabolism of pyruvate

Answer 20

-anaerobic (low O2) muscle or yeast
**- aerobic (normal O2)
TCA cycle

Question 21

what happens to the pyruvate

Answer 21

Depends on :

1) presence / absence of O2
2) the type of organism

Question 22

Pyruvate dehydrogenase consists of 3 major enzymes

Answer 22

E1- pyruvate decarboxylase (uses ATP)
E2- Dihydrolipoate transacetylase (Uses Lipoic Acid)
E3-Dihydrolipoate dehydrogenase (NADH-FADH2 oxidoreductase)

Question 23

PDH cofactors

Answer 23

Thiamine pyrophosphate (TPP)- E1
Lipoic acid -E2
FAD - E3

NAD, CoA

Question 24

What would happen if lipoid acid were not present

Answer 24

acetaldehyde would be produced

yeast route

Question 25

Lipoates acts both as an ______ and an ______

Answer 25

Acyl carrier and electron carrier

Question 26

what would happen if lipoic acid were not present?

Answer 26

acetaldehyde would be produced | pyruvate decarboxylase reaction also used TPP

Question 27

Balancing/analplerotic reaction | 1) pruvate carboxylase

Answer 27

- liver, kidney - activated by AcCoA - important for FA synthesis - gluconeogentic and anaplerotic

Question 28

Balancing/analplerotic reaction | 2) PEP carboxykinase

Answer 28

- heart, muscle | - gluconeogentic and anaplerotic

Question 29

Balancing/analplerotic reaction | 3) PEP carboxylase

Answer 29

- higher plants, yeast, bacteria - ACTIVATED BY FRC 1,6 BIS PHOSPHATE - anaplerotic

Question 30

Balancing/analplerotic reaction | 4) Malic enxyme

Answer 30

- widely distrubted in Euks and Proks - important for FA synthesis - anaplerotic

Question 31

anaplerotic

Answer 31

=balancing or "filling up" reactions

Question 32

Pentose Phosphate Pathway | aka hexose monophosphate shunt and phosphogluconate pathway

Answer 32

an alternate pathway for glucose degradation found in animal cells where NADPH is required

Question 33

NADPH is used in

Answer 33

anabolism (making something)

Question 34

NADH is used in

Answer 34

catabolism (break down)

Question 35

Pentose Phosphate pathway can be divided into 2 sections

Answer 35

1) oxidative phase | 2) non-oxidative phase

Question 36

Pentose Phosphate pathway Oxidative phase

Answer 36

production of energy and pentoses

Question 37

Pentose Phosphate pathway non- oxidative phase

Answer 37

rearrangement of pentoses (C5) back to hexoses (C6)

Question 38

Why do we need Pentose Phosphate pathway (PPP)

Answer 38

1) produce NADPH- reducing power | 2) make pentoses

Question 39

Electron transport chain

Answer 39

under aerobic condition, glycolysis (cytosol) and the TCA (mitochodria) produce reduced e- carriers NADH and FADH2

Question 40

the ETC NADH and FADH2 need to be...... for the pathway to continue

Answer 40

re-oxidized

Question 41

Oxidative phosphorylation

Answer 41

in mitochondiral membrane and is coupled to ATP production

Question 42

Electron transport chaine passes electrons...

Answer 42

down the energy gradient through a series of acceptors with higher and higher reduction potential ending with CO2

Question 43

Electrons entering the ETC are energy rich and as they pass down the chain they lose____

Answer 43

free energy

Question 44

4 major protein compleses that carry the electrons

Answer 44

complex 1 complex 2 complex III Complex IV

Question 45

Complex 1

Answer 45

NADh dehydrogenase, FMN flavoprotein + FeS (6 groups), Coq (ubiquinone)

Question 46

Complex II

Answer 46

Succ dehase (TCA cycle enzyme, membrane bound)

Question 47

Complex III

Answer 47

cytochrom b + c1 + 11 proteins

Question 48

Complex iV

Answer 48

Cytochrome oxidase (a + a3 + 13 proteins)

Question 49

NADH producses how many ATP

Answer 49

2.5 ATP

Question 50

FADH2 produces how many ATP

Answer 50

1.5 ATP

Question 51

Chemiosmotic principle or theory

Answer 51

Delta H+ concentration across membranes and an electricl gradient along are the driving forces for energy production

Question 52

For 2 e- passing down the chain from NADH how many H+ and ATP

Answer 52

10 H+ | 2.5 ATP

Question 53

For 2 e- passing down the chain from FADH2 how many H+ and ATP

Answer 53

6 H+ | 1.5 ATP

Question 54

Energy production from glycolysis

Answer 54

``` 2 NADH2 (ETC) = 5 ATP 2 ATP (sub level phos) = 2 ATP ```

Question 55

Energy production from Pyruvate to Acetyl CoA (mitochondria)

Answer 55

2 NadH2 (ETC) - 5 ATP

Question 56

Energy production from Citric Acid Cylcle (mitochondria)

Answer 56

``` 2 GTP (subst Level phos) 2 ATP 2 FADH2 (ETC) 3 ATP 6 NADH2 (ETC) 15 ATP ```