Lecture # 3 MM Kinetics, enzymes, and Reduction Potential Flashcards
The electron transport chain (ETC) is analogous to a proton pump (T/F)
True
Mitochondria contain their own DNA and a few ribosomes, so some protein synthesis occurs within the mitochondria. (T/F)
True. Mitochondrial DNA codes for mostly proteins of the electron transport chain and ribosomes. Nuclear DNA takes care of the rest.
Km
Michaelis-Menten Constant. [s] at Vmax/2; the lower the Km, the higher the affinity for the substrate;
GLUT3
high affinity glucose receptor; lower Km, used for moments of low glucose concentration; present in the brain
High Affinity trade off Km
The higher the affinity, Km, the lower the capacity for more of substrate (lower Vmax); capacity and affinity are inversely proportional.
GLUT4
Low affinity (5mmol/l); High Capacity. Found in the skeletal muscle.
Hexokinase
phosphorylates glucose for glycolysis once uptaken into a cell. Km 0.1/ high affinity, low capacity
Glucokinase
Also phosphorylates glucose, Km 12, low affinity, high capacity enzyme.
Covalent Modification of Enzymes (Modes)
Phosphorylation (Kinase), dephosphorylation (phosphatase)
Protein Kinase A
First kinase in a cascade that leads to the activation of glycogen phosphorylase. (Adrenaline-B-adrenergic receptor interaction, Gs subunit- GTP to GDP, production of cAMP by adenyly cyclase, cAMP activates protein kinase A, Protein kinase A activates phosphorylase kinase, which activates glycogen phosphorylase
Allosteric Modulation
Allosteric activation and inhibition. usually products or other related metabolites.
Modulation of Enzymes
Covalent modification, allosteric modulation, and synthesis or degradation of enzymes.
1 cal
4.18J
1 kcal
4.18kj
What are the four macromolecules for degradation?
Nucleic acids, proteins, polysaccharides, and lipids and fats. All funnel into the “the powertrain of metabolism’
