Biochemical Compounds

Question 1

lactate dehydrogenase

Answer 1

reduces pyruvate to produce NAD+ and lactate

activated by low oxygen levels

no not loss of carbons

Question 2

bisphosphoglyerate mutase

Answer 2

Produces 2,3- bisphosphoglycerate from 1,3 BPG → binds allosterically to Hb → decreases affinity to O2

present in RBC only bc they do not have mitochondria

Question 3

pyruvate dehydrogenase complex

Answer 3

converts pyruvate to acetyl CoA and produces CO2

• • activated by insulin in liver
• • inhibited by acetyl-CoA and NADH

cofactors are thiamine pyrophosphate, lipoic acid, CoA, FAD, and NAD+

Question 4

pyruvate dehydrogenase kinase

Answer 4

phosphorylates PDH, thus turning it off

activated by ATP or Acetyl CoA

Regulates PDC

Question 5

pyruvate dehydrogenase phosphatase

Answer 5

dephosphorylates PDH to turn it back on

activated by ADP

regulates PDC

Question 6

glycogen synthase

Answer 6

creates alpha-1,4 - glycosidic bonds

• • activated by insulin in the liver and in muscle; also by G6P
• • inhibited by epinephrine and glucagon

this is done in both liver and muscle as the rate-limiting enzyme

Question 7

branching enzyme

Answer 7

moves a block of oligoglucose from one chain and adds it to a growing glycogen via an alpha- 1,6- glycosidic bond

Question 8

glycogen phosphorylase

Answer 8

removes 1 G1P by breaking the alpha - 1,4 - glycosidic bond

• • activated by glucagon in the liver, or epinephrine / AMP in the muscle
• • inhibited by ATP

rate limiting enzyme of breaking down glycogen

Question 9

debranching enzyme

Answer 9

removes a block of oligoglucose from one chain and connects it to the end of a chain via an alpha- 1,4- glycosidic bond

Question 10

pyruvate carboxylase

Answer 10

converts pyruvate into oxaloacetate

activated by acetyl CoA

mitochondrial enzyme

Question 11

phosphoenolpyruvate carboxylase

Answer 11

OAA converted into PEP

activated by glucagon and cortisol

cytoplasmic enzyme

Question 12

glucose 6 phosphatase

Answer 12

converts G6P into free glucose

only found in the endoplasmic reticulum of the liver

Question 13

GLUT2

Answer 13

low affinity (high Km) transporter that brings glucose into the cell

in hepatocytes and pancreatic cells

Question 14

GLUT4

Answer 14

high affinity (low Km) transporter

activated by insulin (which causes increased insertion of GLUT4 transporters on the cell membrane)

in adipose and muscle tissue

Question 15

nucleosidediphosphate kinase

Answer 15

forms ATP from GTP

Question 16

ETC Complex 1

Answer 16

NADH-CoQ oxidoreductase

transfers electrons from NADH to Flavin mononucleotide (FMN) and then to CoenzymeQ

has an iron-sulfur cluster

= 4 PROTONS PUMPED

Question 17

ETC Complex 2

Answer 17

Succinate-CoQ oxidoreductase

transfers electrons from succinate to FAD to coenzymeQ

has an iron-sulfur cluster

= NO PROTEONS PUMPED

Question 18

ETC Complex 3

Answer 18

CoQH2 - cytochrome c oxidoreductase

transfers electrons from CoQH2 to heme in cytochrome c

has an iron sulfur cluster

= 4 PROTONS PUMPED

Question 19

ETC Complex 4

Answer 19

cytochrome c oxidase

transfers electrons from cytochrome c to O2 in the form of H- ions, thus forming water

= 2 PROTONS PUMPED

Question 20

glycerol 3 P shuttle

Answer 20

electrons transferred from NADH → DHAP to form G3P

electrons then transferred to mitochondrial FAD to form FADH2

Question 21

malate aspartate shuttle

Answer 21

electrons transferred from NADH to OAA, forming malate

malate crosses inner mitochondrial membrane and transfers electrons to mitochondrial NAD+

Question 22

ATP synthase

Answer 22

generates ATP from ADP and inorganic P

2 portions: Fo is an ion channel for H+ to pass through, powering the F1 portion to phosphorylate ADP

4 hydrogens for 1 ATP
6 H+ for 1 FADH2, thus 1.5 ATP
8 H+ for 1NADH, thus 2 ATP

Question 23

acetyle CoA carboxylase

Answer 23

adds CO2 to acetyle CoA to form malonyl CoA

activated by insulin and citrate

rate limiting step of FA biosynthesis; requires biotin and ATP

Question 24

fatty acid synthase; aka palmitate synthase

Answer 24

NADPH is required to reduce the acetyl groups added to the FA

8 acetyl CoA groups are used to form palmitate

activated by insulin in the liver

large multienzyme; contains ACP (acyl carrier protein) → requires pantothenic acid