Test 2 - German - Enzymes and Biochem Rxns Flashcards
Cofactors are what?
Inorganic ions
Oxidoreductases catalyze what?
REDOX
Transferases do what?
Group t-fer rxns
Hydrolases do what?
Hydrolysis
Lyases do what?
Cleavage
Isomerases do what?
Transfer of groups for isomeric
Ligases do what?
Condensation rxns
What is Km?
Substrate concentration where the initial rxn velocity equals 1/2 of the max rxn velocity
All inhibition except for comp do what to Vmax?
Reduce it
What causes Km to move right?
Left?
Comp and mixed
Uncomp
What is homotropic vs heterotropic regulation?
Homotropic - Substrate regs enzyme function
Heterotropic - Non-substrate regs enzyme function
-delta G, what does the rxn do?
+delta G, what does the rxn do?
Rxn moves forward
Rxn moves in reverse
What does entropy always do?
Increases
Condensation rxn is what?
2 molecules become one with a small byproduct (H2O)
Carboxylation/decarboxylation?
Addition/removal of carbonyl group
What ratio is maintained intercellularly?
Relatively high ATP:ADP
ATP provides energy via ______, not hydrolysis.
Group transfer
Phosphate groups can be intermediates
What is req’d for effective signaling?
SAMIFF
Specificity Amplification Modularity Integration Feedback Fidelity
Autocrine
Synaptic
Paracrine
Endocrine
Self
Synapse
Immediate environment (Immune system)
Endocrine (Blood)
What are the 4 components of signal transduction?
Signal
Receptor
Transduction pathways
Targets
Signals can be 3 things. Name them
Soluble
Linked
Physical
There are 7 receptor families. Name them and briefly describe them.
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.
What dramatically impacts signaling?
Ligand conc.
What major roles does the membrane play in signaling?
Receptor localization
Ligand exposure
Signaling complex formation
Endocytosis
Signal promotion does what?
Signal inhibition does what?
Put complexes together
Move away complexes
Two types of lipid rafts. Name them.
Caveolar
Planar
Which endocytosis happens in non-lipid raft domains?
Clathrin-mediated endocytosis
Signaling cascade. Name it.
First messenger Receptor Signal transducer Primary effector Second messenger Secondary effector Signaling cascade
MAPK Signaling. What happens?
Ras activates MAPKKK
Phosphorylated to MAPKK and then to MAPK
Then sent to diff. Proteins.
JAK-STAT. Name it.
Phosphate tail of receptor brings “STAT” in when cytokine binds. STAT binds another STAT, then sent to nucleus to activate transcription.
PI3K. Name it.
PIP2 phosphorylated to PIP3. PIP3 then affects PDK1 and AKT.
Phospholipase C Signaling. Name it.
Tied with G-Pro signaling. PIP2 cleaved to DAG and IP3 comes off and causes release of Ca2+. Ca2+ interacts with PKC.
Epinephrine signaling. Low conc. Name it.
Epi binds beta-adrenergic receptor. G-protein activates and binds adenylyl cyclase which interacts with ATP to make cAMP.
Epi/Norepi high concentration. Name it.
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.
Insulin cell division. Name it.
Tyrosine kinase is bound and IRS, Grb, Sos, ras, Raf, MEK, ERK, (Into nuc) SRF/ELK.
Insulin metabolism. Name it.
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.
