Test 2 - German - Enzymes and Biochem Rxns

Question 1

Cofactors are what?

Answer 1

Inorganic ions

Question 2

Oxidoreductases catalyze what?

Answer 2

REDOX

Question 3

Transferases do what?

Answer 3

Group t-fer rxns

Question 4

Hydrolases do what?

Answer 4

Hydrolysis

Question 5

Lyases do what?

Answer 5

Cleavage

Question 6

Isomerases do what?

Answer 6

Transfer of groups for isomeric

Question 7

Ligases do what?

Answer 7

Condensation rxns

Question 8

What is Km?

Answer 8

Substrate concentration where the initial rxn velocity equals 1/2 of the max rxn velocity

Question 9

All inhibition except for comp do what to Vmax?

Answer 9

Reduce it

Question 10

What causes Km to move right?

Left?

Answer 10

Comp and mixed

Uncomp

Question 11

What is homotropic vs heterotropic regulation?

Answer 11

Homotropic - Substrate regs enzyme function

Heterotropic - Non-substrate regs enzyme function

Question 12

-delta G, what does the rxn do?

+delta G, what does the rxn do?

Answer 12

Rxn moves forward

Rxn moves in reverse

Question 13

What does entropy always do?

Answer 13

Increases

Question 14

Condensation rxn is what?

Answer 14

2 molecules become one with a small byproduct (H2O)

Question 15

Carboxylation/decarboxylation?

Answer 15

Addition/removal of carbonyl group

Question 16

What ratio is maintained intercellularly?

Answer 16

Relatively high ATP:ADP

Question 17

ATP provides energy via ______, not hydrolysis.

Answer 17

Group transfer

Phosphate groups can be intermediates

Question 18

What is req’d for effective signaling?

Answer 18

SAMIFF

Specificity
Amplification
Modularity
Integration
Feedback
Fidelity

Question 19

Autocrine
Synaptic
Paracrine
Endocrine

Answer 19

Self
Synapse
Immediate environment (Immune system)
Endocrine (Blood)

Question 20

What are the 4 components of signal transduction?

Answer 20

Signal
Receptor
Transduction pathways
Targets

Question 21

Signals can be 3 things. Name them

Answer 21

Soluble
Linked
Physical

Question 22

There are 7 receptor families. Name them and briefly describe them.

Answer 22

G-Pro - Ligand binding to G-Pro
Receptor tyrosine kinase - ligand binds and tyr-kinase autophosphorylates
Receptor guanylyl Cyclase - ligand - second messenger cGMP
Gated ion - Ionotropic
Adhesion - Molecules in ecm, changes conformation
Nuclear receptor - hormone binding
Cytokine receptor

*All these are metabotropic, except for Ion channels. They are ionotropic.

Question 23

What dramatically impacts signaling?

Answer 23

Ligand conc.

Question 24

What major roles does the membrane play in signaling?

Answer 24

Receptor localization
Ligand exposure
Signaling complex formation
Endocytosis

Question 25

Signal promotion does what? Signal inhibition does what?

Answer 25

Put complexes together Move away complexes

Question 26

Two types of lipid rafts. Name them.

Answer 26

Caveolar Planar

Question 27

Which endocytosis happens in non-lipid raft domains?

Answer 27

Clathrin-mediated endocytosis

Question 28

Signaling cascade. Name it.

Answer 28

``` First messenger Receptor Signal transducer Primary effector Second messenger Secondary effector Signaling cascade ```

Question 29

MAPK Signaling. What happens?

Answer 29

Ras activates MAPKKK Phosphorylated to MAPKK and then to MAPK Then sent to diff. Proteins.

Question 30

JAK-STAT. Name it.

Answer 30

Phosphate tail of receptor brings “STAT” in when cytokine binds. STAT binds another STAT, then sent to nucleus to activate transcription.

Question 31

PI3K. Name it.

Answer 31

PIP2 phosphorylated to PIP3. PIP3 then affects PDK1 and AKT.

Question 32

Phospholipase C Signaling. Name it.

Answer 32

Tied with G-Pro signaling. PIP2 cleaved to DAG and IP3 comes off and causes release of Ca2+. Ca2+ interacts with PKC.

Question 33

Epinephrine signaling. Low conc. Name it.

Answer 33

Epi binds beta-adrenergic receptor. G-protein activates and binds adenylyl cyclase which interacts with ATP to make cAMP.

Question 34

Epi/Norepi high concentration. Name it.

Answer 34

Norepi/epi binds alpha1-adrenergic receptor and the g-pro is activated. It binds to PLC and PIP2 activates DAG and IP3. DAG interacts with PKCi to make PKCa, while IP3 causes Ca2+ interactions.

Question 35

Insulin cell division. Name it.

Answer 35

Tyrosine kinase is bound and IRS, Grb, Sos, ras, Raf, MEK, ERK, (Into nuc) SRF/ELK.

Question 36

Insulin metabolism. Name it.

Answer 36

IRS activates PI3K and that converts PIP2 to PIP3. PKB is phosphorylated by PDK1 which then phosphorylated GSK3, which is not inactive. Glycogen is synthesized. PKB stims the GLUT4 to increase uptake of glucose.