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Test your basic knowledge |
MCAT Organic Chemistry 2
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Study First
Subjects
:
mcat
,
science
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Histidine
only achiral amino acid
aldose
Proteins
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
2. 3 physiological roles of lipids
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
the basic precursor of the molecule (L or D glyceraldehyde)
modulates fluidity and seeks to maintain optimal fluidity
lactase
3. Glycosidic linkage of maltose
glucose - alpha -1 -4- glucose
Proteins
serine - threonine - asparagine - glutamine - cysteine - tyrosine
galactose - beta -1 -4- glucose
4. Amino group placed on the right of a fischer projection is a?
van der Waal forces of hydrophobic tails
D- amino acid
cysteine and methionine
glycerol
5. Hydrophobic and hydrophilic interactions btw amino acids more distant from each other on the polypeptide chain
serine - threonine - asparagine - glutamine - cysteine - tyrosine
3 things about the cyclic form of a sugar as a hemiacetal
tertiary structure
galactose - beta -1 -4- glucose
6. Molecule can act as a base and as an acid
NH2CONH2
amphoteric
C3H6O3 - with one chiral center
2 things about the cyclic form of a sugar as an acetal
7. Hydrophilic amino acids
all acidic - basic - and polar amino acids
glucose - alpha -1 -2- fructose
triacylglycerol
isomers
8. 2 covalent bonds formed in proteins
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
anomers
have amino group in their side chains
peptide bonds and disulfide bonds
9. Unique feature of proline
only amino acid that his a secondary amine
peptide bond
L- configuration
glucose - alpha -1 -4- glucose
10. What kind of lipids compromise the lipid bilayer?
phospholipids
L- amino acid
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
quaternary structure
11. Interaction btw polypeptide subunits arranged in polypeptide. can be covalent bonds or intermolecular forces - disulfide bond that does not form btw residues on the same protein affect (blank)
triacylglycerol
only achiral amino acid
quaternary structure
furanose
12. Enzyme that hydrolyzes lactose into galactose and glucose into
stereoisomers
only achiral amino acid
lactase
modulates fluidity and seeks to maintain optimal fluidity
13. Epimers of sugars that vary in the configuration of their anomeric carbons
anomeric carbon
anomers
the basic precursor of the molecule (L or D glyceraldehyde)
histidine - arginine - lysine
14. Rule for all amino acids that are nonbasic and nonacidic pertaining to pI value?
7.4
will have pI of 6
secondary structure
isoelectric point
15. (+) and (-) describe what?
optical activity
amphipathic
pI
will have pI of 6
16. 3 carbon triol that forms backbone of triacylglycerol
only achiral amino acid
has thiol group that allows it the form disulfide bond
primary structure
glycerol
17. 1.has partial double bond character due to resonance 2. it cannot rotate 3. amide H is someWhat acidic and can H bond
Characteristics of the peptide bond
cysteine and methionine
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
18. Property of fatty acids where one end is hydrophobic and the other is hydrophilic
amphipathic
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
peptide bonds and disulfide bonds
7.4
19. Diastereomers that vary in the configuration of 1 chiral center
epimers
furanose
isomers
modulates fluidity and seeks to maintain optimal fluidity
20. Hydrolysis
histidine - arginine - lysine
addition of water across of a bond
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
has thiol group that allows it the form disulfide bond
21. Basic amino acids
histidine - arginine - lysine
stereoisomers
packing and energy content
2 things about the cyclic form of a sugar as an acetal
22. Covalent bond formed btw carboxyl group of one atom and the amino group of another amino acid in an addition - elimination mechanism - enzymes are required to carry out rxn
peptide bond
isomers
glutamic acid and aspartic acid
amphipathic
23. 1. it requires an enzyme to linearize and mutarotate 2. it is not a reducing sugar and give negative Benedict's test
C3H6O3 - with one chiral center
2 things about the cyclic form of a sugar as an acetal
have amino group in their side chains
lactase
24. Molecules with the same atoms and same bonds - but different bond geometries; can either be enantiomers or diastereomers
stereoisomers
phospholipids
galactose - beta -1 -4- glucose
mutarotation
25. Characteristic of basic amino acids
mutarotation
D- amino acid
alpha helix
have amino group in their side chains
26. Adjacent polypeptide strands running in opposite directions in Beta pleated sheet structure
cysteine and methionine
antiparallel beta sheet
CH3COOH
mutarotation
27. Naturally occurring carbohydrates are formed from what?
D- glyceraldehyde
amphoteric
alpha helix
glucose - alpha -1 -2- fructose
28. Storage form of fatty acid that is composed of 3 esterified fatty acid to a glycerol molecule
addition of water across of a bond
amphoteric
alpha helix
triacylglycerol
29. Glycosidic linkage of lactose
1. presence of strong acids 2. proteolytic enzymes
galactose - beta -1 -4- glucose
have acidic carboxylic acid on side chains - w/ pKa around 4
glutamic acid and aspartic acid
30. What stabilizes lipid bilayer?
furanose
van der Waal forces of hydrophobic tails
saturated fatty acid
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
31. D and L describe what?
primary structure
the basic precursor of the molecule (L or D glyceraldehyde)
peptide bonds and disulfide bonds
glucose - alpha -1 -2- fructose
32. Interconversion btw two anomers
saturated fatty acid
ketose
mutarotation
maltase
33. The amino acid sequence of a protein that is determined by peptide bond
disulfide bond
primary structure
isoelectric point
glucose - alpha -1 -4- glucose
34. Molecules with the same atoms - but different bonds
lactase
anomeric carbon
isomers
have acidic carboxylic acid on side chains - w/ pKa around 4
35. 2 things that accelerate the rate of hydrolysis for peptide cleavage?
1. presence of strong acids 2. proteolytic enzymes
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
Cause of Amino acid separation in gel electrophoresis
will have pI of 6
36. Enzyme that hydrolyzes maltose into 2 glucose molecules?
anomers
maltase
modulates fluidity and seeks to maintain optimal fluidity
will have pI of 6
37. Energy storage molecule of carbohydrates for animals
NH2CONH2
all acidic - basic - and polar amino acids
triacylglycerol
glycogen
38. Right handed helix w/ carboxyl of one amino acid bound to the amine of another amino acid three residues away - proline never resides in this structure b/c it would place a kink in the helix
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
only amino acid that his a secondary amine
ketose
alpha helix
39. Name for 5 membered ring
anomers
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
ketose
furanose
40. Fatty acid w/ no double bonds and maximum number of hydrogens
saturated fatty acid
glycogen
only amino acid that his a secondary amine
2 things about the cyclic form of a sugar as an acetal
41. Unique feature of cysteine
amphipathic
glutamic acid and aspartic acid
has thiol group that allows it the form disulfide bond
triacylglycerol
42. Adjacent polypeptide strands running in the same direction in Beta pleated sheet structure
L- amino acid
parallel beta sheet
mutarotation
L- configuration
43. Fatty acid w/ one or more double bonds in cis form predominately
unsaturated fatty acid
Proteins
amphipathic
cysteine and methionine
44. Initial folding of proteins into shapes stabilized by H bonds btw amino and carboxyl groups of backbone
secondary structure
triacylglycerol
lipases
cysteine and methionine
45. Unique feature of glycine
saturated fatty acid
only achiral amino acid
alpha helix
histidine - arginine - lysine
46. Glycosidic linkage of sucrose
only amino acid that his a secondary amine
glucose - alpha -1 -4- glucose
glucose - alpha -1 -2- fructose
absolute configuration
47. Nonpolar - hydrophobic amino acids
Cause of Amino acid separation in gel electrophoresis
alpha helix
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
ketose
48. Glyceraldehyde
L- configuration
L- amino acid
D- glyceraldehyde
C3H6O3 - with one chiral center
49. Sugar with a carbonyl group at the 2 carbon position
ketose
stereoisomers
glucose - beta -1 -4- glucose
CH3COOH
50. 4 causes of denaturation of proteins
van der Waal forces of hydrophobic tails
primary structure
absolute configuration
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity