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Test your basic knowledge |
MCAT Organic Chemistry 2
Start Test
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. 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)
quaternary structure
have an R group that is polar enough to H bond - but does no acts an acid or a base
glucose - alpha -1 -4- glucose
serine - threonine - asparagine - glutamine - cysteine - tyrosine
2. (R) and (S) describe what?
absolute configuration
modulates fluidity and seeks to maintain optimal fluidity
peptide bonds and disulfide bonds
C3H6O3 - with one chiral center
3. Hydrophilic amino acids
Characteristics of the peptide bond
pyranose
have acidic carboxylic acid on side chains - w/ pKa around 4
all acidic - basic - and polar amino acids
4. Adjacent polypeptide strands running in the same direction in Beta pleated sheet structure
parallel beta sheet
Characteristics of the peptide bond
disulfide bond
epimers
5. The amino acid sequence of a protein that is determined by peptide bond
Proteins
L- amino acid
lipases
primary structure
6. Characteristics of polar amino acids
amphipathic
glutamic acid and aspartic acid
saturated fatty acid
have an R group that is polar enough to H bond - but does no acts an acid or a base
7. Formula for urea
phospholipids
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
have amino group in their side chains
NH2CONH2
8. PH at which positive and negative charges balance to form a zwitterion
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
galactose - beta -1 -4- glucose
pI
amphoteric
9. 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
3 things about the cyclic form of a sugar as a hemiacetal
alpha helix
packing and energy content
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
10. 4 causes of denaturation of proteins
L- configuration
glutamic acid and aspartic acid
quaternary structure
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
11. Sulfur containing amino acids
peptide bond
cysteine and methionine
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
absolute configuration
12. Carbon that in linear form has a carbonyl - or in cyclic form has a hemiacetal or an acetal
all acidic - basic - and polar amino acids
addition of water across of a bond
glycerol
anomeric carbon
13. Separation is due to charge - with negative charge moving toward positive electrode and positive charge moving toward negative electrode
Cause of Amino acid separation in gel electrophoresis
histidine - arginine - lysine
isomers
cysteine and methionine
14. Fxn of cholesterol in the membrane?
modulates fluidity and seeks to maintain optimal fluidity
secondary structure
maltase
D- amino acid
15. Molecule can act as a base and as an acid
amphoteric
glycogen
peptide bond
all acidic - basic - and polar amino acids
16. Name for 6 membered ring
has thiol group that allows it the form disulfide bond
D- glyceraldehyde
L- configuration
pyranose
17. Glyceraldehyde
C3H6O3 - with one chiral center
pyranose
lactase
ketose
18. 1. it requires an enzyme to linearize and mutarotate 2. it is not a reducing sugar and give negative Benedict's test
1. presence of strong acids 2. proteolytic enzymes
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
2 things about the cyclic form of a sugar as an acetal
lipases
19. Molecules with the same atoms and same bonds - but different bond geometries; can either be enantiomers or diastereomers
tertiary structure
L- amino acid
lactase
stereoisomers
20. Characteristics of hydrophobic amino acids
1. presence of strong acids 2. proteolytic enzymes
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
histidine - arginine - lysine
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
21. Adjacent polypeptide strands running in opposite directions in Beta pleated sheet structure
have amino group in their side chains
antiparallel beta sheet
unsaturated fatty acid
mutarotation
22. Amino group placed on the left of a fischer projection is a?
7.4
serine - threonine - asparagine - glutamine - cysteine - tyrosine
L- amino acid
anomeric carbon
23. Structure where H bonds occur btw residues distant from each other - or on a separate chain. backbone is extended rather than coiled
isoelectric point
Beta pleated sheet
glycerol
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
24. Interconversion btw two anomers
mutarotation
have an R group that is polar enough to H bond - but does no acts an acid or a base
C3H6O3 - with one chiral center
antiparallel beta sheet
25. Fatty acid w/ no double bonds and maximum number of hydrogens
saturated fatty acid
all acidic - basic - and polar amino acids
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
Beta pleated sheet
26. Acidic amino acids
galactose - beta -1 -4- glucose
glutamic acid and aspartic acid
7.4
pyranose
27. Amino group placed on the right of a fischer projection is a?
D- amino acid
glycogen
all acidic - basic - and polar amino acids
Proteins
28. Enzyme that hydrolyzes lactose into galactose and glucose into
optical activity
lactase
Cause of Amino acid separation in gel electrophoresis
glucose - alpha -1 -4- glucose
29. Fatty acid w/ one or more double bonds in cis form predominately
unsaturated fatty acid
D- glyceraldehyde
peptide bond
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
30. Hydrophobic and hydrophilic interactions btw amino acids more distant from each other on the polypeptide chain
galactose - beta -1 -4- glucose
pyranose
the basic precursor of the molecule (L or D glyceraldehyde)
tertiary structure
31. PH at which the amino acid has a net neutral charge
L- amino acid
2 things about the cyclic form of a sugar as an acetal
isoelectric point
C3H6O3 - with one chiral center
32. Macromolecule that performs a variety of bodily functions and is composed of up to 20 different amino acids
saturated fatty acid
3 things about the cyclic form of a sugar as a hemiacetal
Proteins
pI
33. Fatty acid structure
quaternary structure
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
absolute configuration
pI
34. Polar amino acids
serine - threonine - asparagine - glutamine - cysteine - tyrosine
phospholipids
C3H6O3 - with one chiral center
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
35. D and L describe what?
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
the basic precursor of the molecule (L or D glyceraldehyde)
parallel beta sheet
addition of water across of a bond
36. 2 covalent bonds formed in proteins
peptide bonds and disulfide bonds
have an R group that is polar enough to H bond - but does no acts an acid or a base
lactase
D- amino acid
37. Characteristics of acidic amino acids
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
the basic precursor of the molecule (L or D glyceraldehyde)
have acidic carboxylic acid on side chains - w/ pKa around 4
Characteristics of the peptide bond
38. 2 things that accelerate the rate of hydrolysis for peptide cleavage?
galactose - beta -1 -4- glucose
1. presence of strong acids 2. proteolytic enzymes
alpha helix
2 things about the cyclic form of a sugar as an acetal
39. (+) and (-) describe what?
optical activity
Proteins
Ka
maltase
40. Glycosidic linkage of maltose
peptide bonds and disulfide bonds
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
cysteine and methionine
glucose - alpha -1 -4- glucose
41. Rule for all amino acids that are nonbasic and nonacidic pertaining to pI value?
optical activity
peptide bonds and disulfide bonds
addition of water across of a bond
will have pI of 6
42. Sugar with an aldehyde at the first carbon position
phospholipids
only amino acid that his a secondary amine
aldose
pyranose
43. 2 reasons why fats have more efficient energy stores than carbs
packing and energy content
amphipathic
tertiary structure
epimers
44. Glycosidic linkage of lactose
CH3COOH
glucose - beta -1 -4- glucose
saturated fatty acid
galactose - beta -1 -4- glucose
45. Sugar with a carbonyl group at the 2 carbon position
ketose
tertiary structure
peptide bond
parallel beta sheet
46. Energy storage molecule of carbohydrates for plants
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
starch
galactose - beta -1 -4- glucose
absolute configuration
47. Basic amino acids
antiparallel beta sheet
Characteristics of the peptide bond
ketose
histidine - arginine - lysine
48. Enzyme that hydrolyzes maltose into 2 glucose molecules?
maltase
Characteristics of the peptide bond
tertiary structure
anomers
49. Unique feature of cysteine
will have pI of 6
glutamic acid and aspartic acid
3 things about the cyclic form of a sugar as a hemiacetal
has thiol group that allows it the form disulfide bond
50. 1.has partial double bond character due to resonance 2. it cannot rotate 3. amide H is someWhat acidic and can H bond
only amino acid that his a secondary amine
phospholipids
Characteristics of the peptide bond
Cause of Amino acid separation in gel electrophoresis