Missed Exam Questions Flashcards
(15 cards)
What was the principal factor determining the migration of individual components in the sample with paper chromatography?
Hydrogen bonding. The relative amount of hydrogen bonding to the stationary phase will determine the relative rate of migration of the various components in the sample.
What type of functional group is formed when aspartic acid reacts with another amino acid to form a peptide bond?
An amide group
What is the difference between an Amine and an Amide
The main difference between amine and amide is the presence of a carbonyl group in their structure; amines have no carbonyl groups attached to the nitrogen atom whereas amides have a carbonyl group attached to a nitrogen atom.
What type of reaction forms a peptide bond? What is the leaving group?
Condensation or dehydration synthesis. H2O is leaving group
Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)?
A.Chlorinating the CH3 group
B.Diluting the solution
C.Adding concentrated HCl(aq)
D.Adding a drop of basic indicator
The answer to this question is C because HCl is a strong acid that will increase the amount of H+ in solution and thus decrease the percentage of CH3CO2H that ionizes.
The intensity of the radiation emitted by the oxygen sensor is directly proportional to the:
A.propagation speed of the radiation.
B.wavelength of the radiation.
C.polarization of photons emitted.
D.number of photons emitted.
The answer to this question is D because the energy of electromagnetic radiation is directly proportional to the number of photons, and the intensity of electromagnetic radiation is defined as energy emitted per unit time. Thus, intensity is directly proportional to the number of photons emitted
What is the conversion from Hz to THz?
1 Hertz = 1x10^-12 THz
What is standard atmospheric pressure in mmHg, Torr, and atm?
760 mmHg, 760 Torr, 1 atm
What does lipase do?
Lipase is an enzyme that breaks down dietary fats into smaller molecules called fatty acids and glycerol.
Which type of bond is formed by glycogen synthase upon release of UDP?
A.α-1,4-Glycosidic bond
B.α-1,6-Glycosidic bond
C.β-1,4-Glycosidic bond
D.β-1,6-Glycosidic bond
The answer is A because the bond that is formed by glycogen synthase is the main chain linkage of glycogen, which is an α-1,4-glycosidic bond. UDP release means that only glucose was added.
What types of bonds occur with glycogen branching?
Branching occurs through an α-1,6-glycosidic bond in glycogen.
Each of the following equations shows the dissociation of an acid in water. Which of the reactions occurs to the LEAST extent?
A.HCl + H2O → H3O+ + Cl−
B.HPO42− + H2O → H3O+ + PO43−
C.H2SO4 + H2O → H3O+ + HSO4−
D.H3PO4 + H2O → H3O+ + H2PO4−
The answer to this question is B. HPO42− has a high negative charge and so dissociation of it will occur to the least extent.
Which of the following most likely will occur if a homogeneous catalyst CANNOT be separated from the products at the end of a reaction?
A.The catalyst will become heterogeneous.
B.The products will be contaminated.
C.The reaction will not occur.
D.The reaction rate will speed up.
The answer to this question is B. If a homogeneous catalyst cannot be separated from the products at the end of a reaction then the products will be contaminated with the catalyst. I
How will the rate of a catalyzed reaction be affected if the solid catalyst is finely ground before it is added to the reaction mixture?
A.The rate will be faster because a greater mass of catalyst will be present.
B.The rate will be faster because a greater surface area of catalyst will be exposed.
C.The rate will be slower because the fine catalyst particles will interfere with product formation.
D.The rate will remain the same because the mass of catalyst will be the same.
The answer to this question is B because grinding a heterogeneous catalyst increases the amount of catalyst available to the reaction and therefore increases its rate.
Which measurement unit CANNOT be used to express power?
A.kg•m2 •s2
B.J•s-1
C.ft•lb •s-1
D.W
The answer to this question is A because the measurement unit of power is watt, defined as J/s = ft•lb/s = kg•m2/s3.
