NS4: CPF Flashcards
Bicarbonate buffer
- equation + enzyme
- concentration effects
Used in blood
CO2 + H2O (+ enz carbonic anhydrase) ⇌ H2CO3 ⇌ HCO3− + H+
As [CO2] increases, then the reaction moves to converting it into bicarbonate and hydrogen ions
As [H+] increases, then pH decreases
how does permeability affect oral medication
If membrane permeability is low, then drugs taken orally will be unable to cross these membranes into the bloodstream.
piezoelectric effect
begins with voltage generating a current through the crystal (electrical energy) and culminates in the crystal vibrating (mechanical energy)
Doppler effect
- what is it
describes how the observed frequency of a sound emitted from an object can change if the object and/or the observer is in motion
- As distance decreases btwn object and observer, the perceived frequency of sound goes higher as the soundwaves get “bunched up”
- As distance increases …. goes lower as the soundwaves get “stretched out”
Doppler Effect
- equation
- sign conventions
f = f0 * (v +/- vr) / (v +/- vs)
where
f is the observed frequency of the wave, expressed in Hz;
f0 is the frequency of the emitted wave, also expressed in Hz;
v is the velocity of the waves in the medium;
vr is the velocity of the receiver;
vs is the velocity of the source
Sign conventions are important when using this equation. The vobserver term is considered positive if the observer is moving toward the source, while vsource is considered positive if the source is moving away from the observer.
define the following:
- attenuation
- amplification
- absorption
- refraction
- scattering
Attenuation: weakening strength of signal
Amplification: increasing strength of signal
Absorption: self explanatory
Refraction: change in the direction of sound wave, as determined by Snell’s law
Scattering: when waves are scattered in all directions in a non-uniform manner, thus reducing signal propagation
range of human hearing + US
Range of human hearing is 20 Hz to 20 kHz
Ultrasound occurs at a frequency above human hearing, thus anything greater than 20 kHz qualifies as ultrasound
how does NADH inhibit gluconeogenesis
NAD+ levels will be unusually low, since the production of NADH naturally involves the depletion of NAD+.
With low NAD+ levels, the future production of OAA and pyruvate (two important gluconeogenic substrates) will be decreased, since pyruvate production is coupled with the conversion of NAD+ to NADH, and since OAA is produced from pyruvate.
Thus, the rate of glucose production via gluconeogenesis will decrease.
What are two reasons that gluconeogenesis cannot be simply termed as “reverse glycolysis”?
production of PEP, glucose, and fructose 6-phosphate by gluconeogenesis-specific enzymes that bypass irreversible steps of glycolysis push the equilibrium of reversible enzymes that function both in glycolysis and gluconeogenesis in the direction of glucose production
Glycolysis contains some steps that are highly exergonic and essentially irreversible under biological conditions, so gluconeogenesis needs to bypass those steps.
Additionally, glycolysis and gluconeogenesis need to be separated in order to prevent a futile cycle in which glucose is broken down to pyruvate and then pyruvate is built back up into glucose.
How does gluconeogenesis bypass the irreversible of early glycolysis?
There’s 3 irreversible steps: hexokinase, phosphofructokinase, and pyruvate kinase.
The early stages of glycolysis (where phosphate groups are added to glucose) must be bypassed by gluconeogenesis. These are irreversible steps in glycolysis that involve the investment of ATP.
– gluconeogenesis bypasses these steps using enzymes that catalyze a simple hydrolysis reaction, splitting off a Pi from the carbohydrate.
The final stage of glycolysis (phosphoenolpyruvate [PEP] → pyruvate) must be bypassed by gluconeogenesis, where pyruvate carboxylase converts pyruvate to oxaloacetate in the mitochondria by adding a COO− group.
– Oxaloacetate is briefly converted to malate for transport out of the mitochondria, where it is then converted immediately back to oxaloacetate. At this point, in the cytosol, PEP carboxykinase converts oxaloacetate to PEP.
formulas
- straight chain alkanes
- sc alkenes
- sc alkynes
Straight-chain alkanes have the general formula CnH2n+2, while straight-chain alkenes with a single double bond have the general formula CnH2n, and straight-chain alkynes with a single triple bond have the general formula CnH2n−2.
How to find the # of double bonds in an unsaturated compound pls, thanks
Determine the number of double bonds in an unsaturated compound by using (2C + 2 + N – H – X)/2, where C is the number of carbons, N is the number of nitrogens, H is the number of hydrogens, and X is the number of halogens.
Rate law
arrhenius eq
The rate law of a general reaction of the form aA + bB → cC + dD is: rate = k[A]x[B]y.
The Arrhenius equation, k = Ae^ {-Ea/(RT)} , expresses the relationship between the rate constant, k, and the temperature of a reaction. As temperature increases, the reaction rate also increases
conjugation
huckel’s rule
special case of resonance that occurs when three or more adjacent p-orbitals are aligned with each other, forming not just a π bond, but a π system through whihc electrons can delocalize
– Can absorb ultraviolet (UV) light, and can therefore be well visualized using UV spectroscopy
Huckel’s rule: having (4n + 2) π-electrons, where n is an integer
why use bicarbonate ion as a buffer
An amphiprotic species is one that can act as both an acid or a base.
Eg. bicarbonate ion, HCO3-, can act as a Bronsted-Lowry acid by loss of a hydrogen ion and can act as a B-L base by accepting a hydrogen ion to form carbonic acid, H2CO3.
