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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. Naturally occurring carbohydrates are formed from what?
absolute configuration
D- glyceraldehyde
glycogen
saturated fatty acid
2. Hydrophobic and hydrophilic interactions btw amino acids more distant from each other on the polypeptide chain
disulfide bond
tertiary structure
addition of water across of a bond
D- glyceraldehyde
3. Fxn of cholesterol in the membrane?
3 things about the cyclic form of a sugar as a hemiacetal
anomers
unsaturated fatty acid
modulates fluidity and seeks to maintain optimal fluidity
4. (R) and (S) describe what?
glycogen
Proteins
have amino group in their side chains
absolute configuration
5. 2 covalent bonds formed in proteins
amphipathic
peptide bonds and disulfide bonds
glutamic acid and aspartic acid
furanose
6. 3 physiological roles of lipids
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
7.4
1. presence of strong acids 2. proteolytic enzymes
isoelectric point
7. Acidic amino acids
aldose
glutamic acid and aspartic acid
starch
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
8. Glycosidic linkage of cellulose
glucose - beta -1 -4- glucose
isomers
Proteins
3 things about the cyclic form of a sugar as a hemiacetal
9. PH at which the amino acid has a net neutral charge
mutarotation
isoelectric point
lipases
starch
10. What stabilizes lipid bilayer?
starch
galactose - beta -1 -4- glucose
amphipathic
van der Waal forces of hydrophobic tails
11. Adjacent polypeptide strands running in opposite directions in Beta pleated sheet structure
galactose - beta -1 -4- glucose
antiparallel beta sheet
peptide bonds and disulfide bonds
optical activity
12. Generated btw either thiols on different proteins or thiols on the same protein
Characteristics of the peptide bond
only amino acid that his a secondary amine
disulfide bond
Cause of Amino acid separation in gel electrophoresis
13. (+) and (-) describe what?
D- amino acid
disulfide bond
optical activity
anomers
14. 1. it exists in solution in equilibrium with linear form 2. mutarotation occurs readily 3. it is a reducing sugar - and reacts positively w/ Benedict's reagent
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
tertiary structure
3 things about the cyclic form of a sugar as a hemiacetal
lactase
15. 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
alpha helix
C3H6O3 - with one chiral center
aldose
3 things about the cyclic form of a sugar as a hemiacetal
16. Separation is due to charge - with negative charge moving toward positive electrode and positive charge moving toward negative electrode
absolute configuration
D- amino acid
Cause of Amino acid separation in gel electrophoresis
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
17. Rule for all amino acids that are nonbasic and nonacidic pertaining to pI value?
has thiol group that allows it the form disulfide bond
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
will have pI of 6
amphoteric
18. Enzymes that hydrolyze fats
lipases
disulfide bond
will have pI of 6
van der Waal forces of hydrophobic tails
19. Name for 5 membered ring
furanose
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
Ka
Characteristics of the peptide bond
20. Characteristic of basic amino acids
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
isomers
have amino group in their side chains
aldose
21. Characteristics of hydrophobic amino acids
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
van der Waal forces of hydrophobic tails
tertiary structure
glucose - alpha -1 -4- glucose
22. What describes the affinity of functional groups for a proton?
galactose - beta -1 -4- glucose
Ka
7.4
pI
23. Molecules with the same atoms - but different bonds
glycerol
isomers
starch
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
24. Hydrolysis
optical activity
aldose
addition of water across of a bond
2 things about the cyclic form of a sugar as an acetal
25. Glycosidic linkage of maltose
quaternary structure
7.4
glucose - alpha -1 -4- glucose
glycerol
26. Polar amino acids
NH2CONH2
serine - threonine - asparagine - glutamine - cysteine - tyrosine
only achiral amino acid
amphipathic
27. Adjacent polypeptide strands running in the same direction in Beta pleated sheet structure
L- amino acid
parallel beta sheet
Cause of Amino acid separation in gel electrophoresis
1. presence of strong acids 2. proteolytic enzymes
28. Molecule can act as a base and as an acid
galactose - beta -1 -4- glucose
amphoteric
1. presence of strong acids 2. proteolytic enzymes
stereoisomers
29. 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
all acidic - basic - and polar amino acids
packing and energy content
3 things about the cyclic form of a sugar as a hemiacetal
30. 1. it requires an enzyme to linearize and mutarotate 2. it is not a reducing sugar and give negative Benedict's test
2 things about the cyclic form of a sugar as an acetal
optical activity
maltase
has thiol group that allows it the form disulfide bond
31. Characteristics of polar amino acids
have an R group that is polar enough to H bond - but does no acts an acid or a base
phospholipids
Proteins
antiparallel beta sheet
32. Acetic acid formula?
CH3COOH
have acidic carboxylic acid on side chains - w/ pKa around 4
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
epimers
33. Hydrophilic amino acids
all acidic - basic - and polar amino acids
anomers
glycerol
lactase
34. Glycosidic linkage of lactose
antiparallel beta sheet
maltase
D- glyceraldehyde
galactose - beta -1 -4- glucose
35. Diastereomers that vary in the configuration of 1 chiral center
epimers
parallel beta sheet
lipases
unsaturated fatty acid
36. Structure where H bonds occur btw residues distant from each other - or on a separate chain. backbone is extended rather than coiled
Beta pleated sheet
peptide bond
Characteristics of the peptide bond
CH3COOH
37. 2 things that accelerate the rate of hydrolysis for peptide cleavage?
1. presence of strong acids 2. proteolytic enzymes
amphipathic
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
modulates fluidity and seeks to maintain optimal fluidity
38. Unique feature of cysteine
has thiol group that allows it the form disulfide bond
anomers
galactose - beta -1 -4- glucose
isomers
39. Characteristics of acidic amino acids
have acidic carboxylic acid on side chains - w/ pKa around 4
only achiral amino acid
have amino group in their side chains
addition of water across of a bond
40. Storage form of fatty acid that is composed of 3 esterified fatty acid to a glycerol molecule
lipases
Cause of Amino acid separation in gel electrophoresis
triacylglycerol
quaternary structure
41. The amino acid sequence of a protein that is determined by peptide bond
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
have acidic carboxylic acid on side chains - w/ pKa around 4
have an R group that is polar enough to H bond - but does no acts an acid or a base
primary structure
42. Physiological pH
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
7.4
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
disulfide bond
43. Fatty acid w/ no double bonds and maximum number of hydrogens
pI
D- glyceraldehyde
saturated fatty acid
only amino acid that his a secondary amine
44. Initial folding of proteins into shapes stabilized by H bonds btw amino and carboxyl groups of backbone
have amino group in their side chains
the basic precursor of the molecule (L or D glyceraldehyde)
modulates fluidity and seeks to maintain optimal fluidity
secondary structure
45. Fatty acid structure
unsaturated fatty acid
disulfide bond
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
galactose - beta -1 -4- glucose
46. What kind of lipids compromise the lipid bilayer?
maltase
Cause of Amino acid separation in gel electrophoresis
phospholipids
serine - threonine - asparagine - glutamine - cysteine - tyrosine
47. Amino group placed on the left of a fischer projection is a?
Proteins
unsaturated fatty acid
packing and energy content
L- amino acid
48. Nonpolar - hydrophobic amino acids
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
histidine - arginine - lysine
saturated fatty acid
tertiary structure
49. Enzyme that hydrolyzes lactose into galactose and glucose into
amphoteric
starch
lactase
cysteine and methionine
50. 3 carbon triol that forms backbone of triacylglycerol
serine - threonine - asparagine - glutamine - cysteine - tyrosine
glucose - alpha -1 -2- fructose
Characteristics of the peptide bond
glycerol