Answer: C and D
Question: Besides a large spot and the TLC sample being too concentrated, what two other factors can cause the developed spots to appear as a streak?
Answer: If there are too many components in a sample, the developed spots will appear as a streak. Also, if the sample being separated is not soluble in silica gel, it may decompose and cause a streaky spot.
Question: Where should you dispose of disposable glassware?
Answer: Dispose of broken glass in a “broken glass” cardboard container.
Question: Which of the following is an example of posttranslational modification of proteins?
Answer Options:
Phosphorylation
Acetylation
Proteolytic Cleavage
Glycosylation
All of the above are examples of posttranslational modification
Answer: All of the above are examples of posttranslational modification
Question: The following molecule is an example of which class of compounds? Molecular Structure: CH3(CH2)4COOCH(CH3)2
Answer Options:
Hydrocarbon
Acid
Ester
Ether
Aldehyde
Answer: Ester
Question: The enzyme fumarase catalyzes the reversible hydration of fumaric acid to L-malate, but it will not catalyze the hydration of maleic acid, the cis isomer of fumaric acid. This is an example of:
Answer Options:
biological activity
chiral catalysis
racemization
stereospecificity
stereoselectivity
Answer: stereospecificity
Question: The name of this sugar is: Chemical structure provided for a sugar molecule
Answer Options:
D-Galactose
D-Ribose
L-Arabinose
D-Glucose
Answer: D-Glucose
Question: Which of the following is not a homoglycan?
Answer Options:
Cellulose
Glycogen
Starch
Heparin
Amylose
Answer: Heparin
Question: When measuring the effects of pH, how did the authors prove that the ionic strength of the buffer being used wasn’t leading to false data?
Answer Options:
They used all the same concentrations of buffers.
They used all the same buffers.
They used different buffers at each pH.
They didn’t use buffers at all.
None of the above.
Answer: They used different buffers at each pH.
Question: Determine the pKa for the following solution of acid containing [0.022] A- and [0.11] HA. The pH of the solution is 5.24.
Answer Options:
4.10
4.76
5.90
6.5
7.00
Answer: 4.76
Question: The crystallization step of recrystallization removes which category of impurities?
Answer Options:
a. on the surface of the solid
b. within the crystal lattice
Answer: b. within the crystal lattice
Question: What is the function of the aromatase enzyme?
Answer Options:
It kills a tyrosine.
It transforms cholesterol to sugars.
It changes testosterone to estrogen (7-alpha estradiol)
It phosphorizes a serine on estrogen.
None of the above.
Answer: It changes testosterone to estrogen (7-alpha estradiol)
Question: What device should you use if concentrated acid or base spills on your clothing?
Answer: Go to the safety shower and wash.
Question: What should you try first if a very small fire starts on your desk?
Answer: If a fire starts in a beaker or flask, cover the vessel with a flat object to cut off the supply of air.
Question: A biochemical reaction will proceed in the direction as written (left to right) if:
Answer Options:
ΔG > 0
ΔG < 0
Answer: ΔG < 0
Question: Table of reagents: Use Table Feature on the choices above the text box to create a table with the required information.
Answer: The table contains molecular formula, molecular weight, melting point, boiling point, solubility, and density for cyclohexane and toluene.
Question: In glycoproteins carbohydrate is most often linked to threonine, asparagine or ______.
Answer: Serine
Question: Both glycogenesis and glycogenolysis are controlled primarily by the interplay between the two hormones insulin and glucagon.
Answer Options:
Insulin
Glucagon
Fructose kinase
Glucagon hyperbolism
Answer: Both A and B are correct
Question: What is the primary factor that determines how long it takes a star to form?
Answer Options:
Its mass
Whether multiple stars form from the same nebula
Molecular cloud mass
Whether the protostar forms quickly or slowly
Luminosity
Answer: Its mass
Question: What does it mean to say the Sun is in a state of hydrostatic equilibrium?
Answer Options:
Hydrogen in the solar interior is balanced by the hydrogen in its atmosphere.
The pressure of gravity pulling inward is balanced by the pressure of nuclear fusion pushing outward.
The magnetic field of the Sun is in balance with its rotational speed.
Answer: The pressure of gravity pulling inward is balanced by the pressure of nuclear fusion pushing outward.
Question: A disk of gas and dust appears to be an essential part of star formation.
Answer Options:
True
False
Answer: True