Terms in this set (40)
increased Km, Vmax unchanged
Km decrease and Vmax decrease
Km unchanged, Vmax decreased
Which of the following is true of enzymes?
They increase the rate of reaction by stabilizing the transition state
When a molecule serves as a substrate for its target enzyme, as well as a regulatory molecule of the enzyme's activity
Example: O2 is a homotropic allosteric modulator of Hb
Occurs when an enzyme binds the inhibitor and forms an irreversible complex with it, usually through a covalent bond. This can involve the inhibitor being chemically modified by the enzyme during the normal course of catalysis to produce a reactive group that is specifically responsible for the formation of the irreversible inhibitor - enzyme complex
Residual Volume (lungs)
Pressure and volume are inversely related, so under maximum pressure, the lungs will reach a minimum volume. This volume of air remaining is the residual volume
Only able to bind to other RNA strands, not to DNA or protein. Therefore, it must interfere with gene expression after transcription has already occurred, but before translation.
Specifically prevents the translation of mRNA corresponding to the target protein
Pentose Phosphate Pathway
produces NADPH, which is a molecule required for the neutralization of reactive oxygen species including oxygen radicals
Amino End AA
Carboxyl End AA
pH above isoelectric points? Below isoelectric point?
migrate toward anode (positive electrode)
Migrate towards cathode (negative electrode)
Empirical formula Carbohydrates
identify reducing sugars, sugars with hemiacetal groups that can undergo mutarotation
Classic example = glucose
How to determine how many stereoisomers exist in a compound?
2^n (n = number of chiral centers)
one method of isolating polypeptides and proteins from aqueous extracts is freeze drying. The aqueous solution of the polypeptide or protein is frozen. What procedure can be used to remove the water from the frozen sample?
Sublimation under reduced pressure
Because only sublimation of the water under reduced pressure will keep the mixture cold and will maintain the protein in its native state
positive hydropathy index
means the amino acids are hydrophobic and therefore more likely to reside within a plasma membrane
what is the dependent variable in an experiment that determines the Michaelis - Menten kinetic parameters of an enzyme?
which combination of lipid type and temperature results in the most disordered membrane?
Lipids with unsaturated acyl chains at high temperature
Lipids with unsaturated acyl chains do not pack well against one another, increasing the level of disorder. Increased temperature also increases the level of disorder in the membrane because there is more movement at higher temperatures
Which event is LEAST likely to occur during apoptosis?
Damage to nearby cells caused by lysis
Damage to nearby cells caused by lysis is a characteristic of necrosis, not apoptosis
Kcat is the turnover number -- the number of substrate molecule each enzyme site converts to product per unit time. If you know the concentration of enzyme sites, you can fit Kcat instead of Vmax when analyzing a substrate vs. velocity curve.
Which enzymatic kinetic parameter is NOT affected by the presence of an uncompetitive inhibitor?
Km / Vmax
uncompetitive inhibitors affect both the Kcat and Km of an enzymatically catalyzed reaction in a way that does not change the slope which means the Km/Vmax is not changed,
Binding dissociation Kd
the protein with the lowest binding dissociation constant has the highest affinity for its ligand. The dissociation constant represents the ligand concentration that is necessary to achieve 50% binding
Specific activity is a measure of
the enzyme units per milligram of total protein in a solution
This provides a measure of the purity of an enzymatic mixture
A heterotrimeric protein consists of 3 subunits with molecular weights of 10 Kda, 40 Kda, and 100 kda. The protein is denatured with 3M urea and subjected to size exclusion chromatography. Which solute is the last compound elute from the column?
Because a size - exclusion column allows larger molecules to pass more freely through the column matrix and hinders the passage of smaller molecules. Urea is this smallest solute and would be the last to elute
Compared to a dinunsaturated acyl chain of a lipid, a saturated acyl chain possesses how many more total hydrogen atoms?
Because each double bond in an acyl chain removes 2 hydrogen atoms when compared with fully saturated chains
Researchers noted that in the absence of a reducing agent the elution time of a certain protein from a size - exclusion column decreased considerably relative to the elution time when the buffer contained a reducing agent. Which type of molecular interaction was responsible for this observation?
Disulfide bond between two subunits of a protein would cause the protein to have a different elution time on a size - exclusion column. The fact that reducing agents eliminate this interaction is more evidence that a dissulfide bond was present
Uracil is produced from cytosine as a result of a conversion of
An amine group to a carbonyl group
The deamination of cytosine, the amine group of cytosine is replaced with a carbonyl group
Disruption of two disulfide bonds within a protein requires
2 molecules of NADH
Because the reduction of a disulfide bond requires two electrons and each molecule of NADH can provide two electrons when reducing another compound