Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CHM 352 > Test Keys > Flashcards

Test Keys Flashcards

1
Q

In thermodynamics, the term H refers to:

A

Enthalpy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In a water molecule, hydrogens are partially ______; oxygens are partially _____.

A

Positive; ; negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

ATP would contain how many phosphate groups?

A

Three

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The biomolecule that is not often found as a polymeric version is _____.

A

Lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of following compounds is amphipathic?
-H2O
-(CH3)2(CH2)3
-HOOCCOOH
-CH3CH2CH2Ch2CH2COOH

A

CH3CH2CH2CH2COOH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A molecule that has both a polar and nonpolar region is called

A

Amphiphilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When a non-polar substance is added to water, how do the molecules of water behave?

A

The regular hydrogen bond pattern is disrupted resulting in a decrease of ENTROPY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What term is used to describe the exclusion of non-polar substances from an aqueous solution?

A

Hydrophobic effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Considering the energetics of transferring non-polar molecules from water to a non-polar solvent, the factor TdeltaS is generally _____, causing deltaG to be _____.

A

Positive; negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following amino acids has an amide group in its side chain?
-Ser
-Asn
-Cys
-Tyr
-Met

A

Asn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which of the following amino acids has a non-polar side chain?
-Ser
-Val
-Lys
-Asn
-None of these choices?

A

Val

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Disulfide bonds form between two residues of which amino acids?
-Met
-Ser
-Asn
-Thr
-Cys

A

Cys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Based upon its side chain, how is the amino acid Ser classified?

A

Polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which of the 20 standard amino acids is optically inactive?

A

Gly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

If a protein underwent a mutation such that an Asp residue was changed to another amino acid, which of the following amino acids would least likely result in a change in the overall structure of the protein?
-Ser
-Glu
-Gln
-Lys
-Ala

A

Glu

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

At a pH above its pKa, the R-group of Asp is _____.

A

deprotonated and negatively charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the N-terminal amino acid in the pentapeptide Val-Leu-Arg-Ser-Gly?

A

Val

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which of the following structures shows the prevalent form of glutamic acid pH 3 ?

A

The answer is the one with H3N+ and an O- on the COO end; and an OH group pointing downward.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the net charge on the following peptide at pH 9.5? chart Asp-Ala-Glu-Gln-Asp-Ile

A

-4 is the answer though for this polypeptide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The predominant non-covalent interaction seen in alpha helices and beta sheets is ____.

A

Hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of the following amino acids is generally absent from an alpha helix?
-Trp
-Ser
-Ile
-Pro
-None of these

A

Pro

22
Q

Alpha helices and beta sheets comprise ____ structure.

A

Secondary

23
Q

The following is an example of ______.
*picture of highlighted H—-O bonds and C—N backbones

A

Antiparallel Beta sheet

24
Q

If the following mixture of proteins was applied to a size-exclusion chromatography column, what would be the order of elution?
Proteins with molecular weights: myoglobin (17.7 kDa), hemoglobin (64.5 kDa), lysozyme (14.3 kDa), and triose phosphate isomerase (57.4 kDa)

A

Hemoglobin, triose phosphate isomerase, myoglobin, lysozyme

25
Q

Hemoglobin is ______; myoglobin is ____.

A

Tetrameric; monomeric

26
Q

The individual hemoglobin subunits and myoglobin share a similar ____ structure but have a rather different _____ structure.

A

Secondary and tertiary; primary

27
Q

The central ion of the heme group of hemoglobin is _____.

A

Fe2+

28
Q

The idea that binding of one molecule of oxygen to hemoglobin enhances further binding of oxygen to hemoglobin is called _____.

A

Cooperativity

29
Q

A plot of the binding of oxygen to myoglobin as a function of pO2 gives a _____ shape; a similar plot for hemoglobin gives a ____ shape.

A

hyperbolic; sigmoidal

30
Q

Highly active muscle generates lactic acid by respiration so rapidly that blood passing through the muscle drops in pH from 7.4 to 7.2. Would Hb bind O2 with higher or lower affinity at 7.2 than it does at pH 7.4?

A

Lower affinity

31
Q

How is the enzyme-catalyzed reaction affected by the addition of more enzyme?

A

Velocity will increase

32
Q

Which of the following must be true if the steady state assumption is to be used?

A

d[ES] / dt = 0

33
Q

An extremely efficient enzyme has a _____ Km and a ____ kcat.

A

Small; large

34
Q

In a bisubstrate reaction, reactant A binds and is then converted to product C. Next, reactant B binds and is then converted to product D. An experiment showed that B Cannot bind without C being released first. What mechanism is indicated by this data?

A

Ping Pong Mechanism

35
Q

How are the kinetics of an enzyme-catalyzed reaction affected by a competitive inhibitor?

A

Vmax unchanged, Km decreased

36
Q

Which of the following statements regarding allosteric enzymes is true?

A

All of the Above: Choices include;
They are always oligomeric, they generally found at regulatory sites in metabolic pathways, they are subject to regulation by both positive and negative effectors, a plot of velocity versus [Substrate] often yields a sigmoidal curve

37
Q

What three amino acids are found in the catalytic triad of chymotrypsin?

A

Asp, His, Ser

38
Q

If the Asp in the chymotrypsin active site was mutated to another amino acid, which of the following would be considered an invisible mutation in that it is least likely to impact the function of the enzyme?

A

Asp —> Glu

39
Q

Which of the following is a potent activator of phosphofructokinase in mammals?

A

Fructose-2,6-biphosphate

40
Q

What enzyme catalyzes the major regulatory step of glycolysis?

A

PFK (phosphofructokinase)

41
Q

During the first half of the chymotrypsin mechanism where the acyl-enzyme intermediate is formed, what role does His play?

A

General base then general acid

42
Q

Which of the following enzymes catalyzes an irreversible process?

A

Pyruvate Kinase

43
Q

With a deltaGnautprime of -16.7 kJ/mol, the reaction catalyzed by hexokinase is considered to be

A

metabolically irreversible

44
Q

Which of the following amino acids would be most likely found in the active site of an enzyme that uses acid-base catalysis?

A

His

45
Q

The enzyme responsible for the synthesis of fructose-2,6-bisphosphate is ____.

A

Phosphofructokinase-2

46
Q

How does a catalyst increase the rate of reaction?

A

It allows reacting molecules to more easily form the transition state

47
Q

Which of the following amino acids would be most likely found in the active site of an enzyme that uses acid-base catalysis?

A

His

48
Q

When the transition state is formed, what is the specific interaction observed between Asp and His that helps stabilize the transition state?

A

Low-barrier hydrogen bond

49
Q

A plot of velocity versus substrate concentration for a simple enzyme-catalyzed reaction produces a _____. This indicates that at some point, the enzyme is _____.

A

Hyperbolic curve; saturated with substrate

50
Q

Titration of valin by a strong base, for example NaOH, reveals two pK’s. The titration reaction ocurring at pK2 (pk2 = 9.62) is:

A

NH3+ + OH —NH2 + H2O

51
Q

At a pH above its pKa, the R-Group of Asp is ____.

A

Deprotonated and negatively charged

CHM 352 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions