AAMC FL#2 Flashcards
Equilibrium constants (Keq,Ka, Kb, Kw) are all….
temperature dependent
A higher wavelength means higher or lower energy level?
Higher wavelength is lower energy level so less absorbed photon energy
k cat is???
k cat is the number of substrate molecules converted to product per enzyme per second
Venturi effect
volume flow rate has to be same through different parts of tubes so that water will flow faster in areas with smaller radii –> meaning this area will have lower pressure (bernoulli’s equation)
Why G-C bonds are stronger?
they have pi-bond stacking strength
what are the storage lipids?? their structure?
triacylglycerols - 3 FAs ester linked to a single glycerol
charles law
V/T
If kf (constant of formation) is > 1 then delta G is….
kf = products/reactants and delta G = -RT ln (k) at equilibrium so if kf is >1, then delta G is negative because reaction is spontaneous and products are favored
coordinate covalent bonds
coordinate covalent bonds are usually Lewis acid/base reactions and are mostly between a metal ion and an electron pair donor
Metals have ________ ionization energies than nonmetals
Metals have lower ionization energies than nonmetals
If Ka is lower, then the acid is stronger or weaker?
weaker acid because there is less dissociation - think math - because acid is on denominator of equation
Bond dissociation energy
delta H = sum of H of (BONDS BROKEN) - sum of H of (BONDS FORMED)
H of formation
Hf(products) - Hf(reactants)
What functional group is this?
nitro group
Protein secondary structure is characterized by the pattern of hydrogen bonds between
backbone amide protons and carbonyl oxygens
facts about diverging lens
ALWAYS create a virtual, upright image that is reduced; Image is always on object’s side of the lens
Also diverging lens are concave lens
Also has a -f (focal length) and -r (radius of curvature)
formula relating sound level and intensity
Intensity = Power/Area
PFK-1 inhibited by ___ and activated by _____
How does fructose-2,6BP play in the activation/inhibition scenario?
PFK-1 is inhibited by ATP and citrate and activated by AMP.
Insulin indirectly stimulates PFK-1 (while glucogon indirectly inhibits) in HEPATOCYTES (where most PFK-2 are found); insulin STIMULATES PFK-2 first, which converts some Fructose-6P to Fructose 2,6-BP; Fructose 2,6-BP then ACTIVATES!!!! PFK-1 to override inhibition by ATP !!!! – glcolysis proceeds
substrate level phosphorylation
uses high energy intermediate to create ATP through direct phosphorylation
pyruvate kinase is activated by______
by fructose 1,6-BP from the PFK-1 reaction; this is a feed forward activation - so product of earlier reaction stimulates later reaction
hexokinase vs glucokinase
hexokinase - widely distributed in tisssues; inhibited by its produt - glucose -6P; has LOW Km(reaches maximum velocity at low [glucose]
glucokinase - found ONLY in liver and pancreatic beta-islet cells; in liver, glucokinase is induced by insulin; along with GLUT 2, it acts as a glucose sensor; has HIGH Km (acts on glucose proportionally to its concentration)
lactate dehydrogenase
oxidizes NADH to NAD+ in mammalian fermentation by changing pyruvate into lactate; pyruvate and lactate are 3 carbon molecules; NAD+ now used in glycolysis to make ATP!
In yeast fermentation; pyruvate (3C) converted to ethanol (2C) and carbon dioxide (1C) but also makes NAD+!!!!!
other roles of DHAP
DHAP - dihydroxyactone phosphate in glycolysis forms glycerol-3-phosphate, which is then conerted to glycerol for TRIACYLGLYCEROL SYNTHESIS in HEPATIC and ADIPOSE TISSUE
What is the special RBC enzyme?
bisphosphoglycerate mutase - which produces 2,3-bisphosphoglycerate (2,3-BPG) from 1,3BPG;
2,3-BPG binds ALLOSTERICALLY to beta chains of HbA and DECREASES its affinity for O2
2,3BPG DOESNT bind well to HbF - fetal Hb - so HbF has HIGHER affinity for O2 than maternal HbA
