SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
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. 2 things that accelerate the rate of hydrolysis for peptide cleavage?
isoelectric point
peptide bond
1. presence of strong acids 2. proteolytic enzymes
aldose
2. Hydrophobic and hydrophilic interactions btw amino acids more distant from each other on the polypeptide chain
Characteristics of the peptide bond
tertiary structure
isoelectric point
glucose - beta -1 -4- glucose
3. Histidine
pI
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
glucose - alpha -1 -4- glucose
packing and energy content
4. Hydrophilic amino acids
L- configuration
all acidic - basic - and polar amino acids
have acidic carboxylic acid on side chains - w/ pKa around 4
anomeric carbon
5. Interconversion btw two anomers
Beta pleated sheet
all acidic - basic - and polar amino acids
mutarotation
L- amino acid
6. What stabilizes lipid bilayer?
phospholipids
van der Waal forces of hydrophobic tails
modulates fluidity and seeks to maintain optimal fluidity
serine - threonine - asparagine - glutamine - cysteine - tyrosine
7. 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
modulates fluidity and seeks to maintain optimal fluidity
CH3COOH
8. Characteristics of hydrophobic amino acids
Cause of Amino acid separation in gel electrophoresis
quaternary structure
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
isoelectric point
9. 3 physiological roles of lipids
D- glyceraldehyde
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
optical activity
have acidic carboxylic acid on side chains - w/ pKa around 4
10. Naturally occurring carbohydrates are formed from what?
antiparallel beta sheet
2 things about the cyclic form of a sugar as an acetal
3 things about the cyclic form of a sugar as a hemiacetal
D- glyceraldehyde
11. Enzyme that hydrolyzes maltose into 2 glucose molecules?
D- amino acid
7.4
maltase
isomers
12. Molecules with the same atoms and same bonds - but different bond geometries; can either be enantiomers or diastereomers
lipases
NH2CONH2
the basic precursor of the molecule (L or D glyceraldehyde)
stereoisomers
13. 1. it requires an enzyme to linearize and mutarotate 2. it is not a reducing sugar and give negative Benedict's test
disulfide bond
histidine - arginine - lysine
2 things about the cyclic form of a sugar as an acetal
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
14. 4 causes of denaturation of proteins
furanose
peptide bonds and disulfide bonds
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
quaternary structure
15. 1.has partial double bond character due to resonance 2. it cannot rotate 3. amide H is someWhat acidic and can H bond
Ka
serine - threonine - asparagine - glutamine - cysteine - tyrosine
L- amino acid
Characteristics of the peptide bond
16. Acetic acid formula?
anomers
NH2CONH2
isomers
CH3COOH
17. Unique feature of proline
starch
alpha helix
glycerol
only amino acid that his a secondary amine
18. PH at which positive and negative charges balance to form a zwitterion
pI
glycogen
1. presence of strong acids 2. proteolytic enzymes
packing and energy content
19. Adjacent polypeptide strands running in opposite directions in Beta pleated sheet structure
tertiary structure
anomers
quaternary structure
antiparallel beta sheet
20. Fatty acid w/ no double bonds and maximum number of hydrogens
saturated fatty acid
3 things about the cyclic form of a sugar as a hemiacetal
glycerol
antiparallel beta sheet
21. 3 carbon triol that forms backbone of triacylglycerol
secondary structure
anomers
glycerol
C3H6O3 - with one chiral center
22. What describes the affinity of functional groups for a proton?
van der Waal forces of hydrophobic tails
Ka
isomers
D- amino acid
23. Molecules with the same atoms - but different bonds
C3H6O3 - with one chiral center
isomers
Ka
anomeric carbon
24. Storage form of fatty acid that is composed of 3 esterified fatty acid to a glycerol molecule
mutarotation
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
peptide bonds and disulfide bonds
triacylglycerol
25. Name for 5 membered ring
only amino acid that his a secondary amine
anomers
pyranose
furanose
26. Sulfur containing amino acids
cysteine and methionine
primary structure
D- amino acid
2 things about the cyclic form of a sugar as an acetal
27. Formula for urea
packing and energy content
glucose - beta -1 -4- glucose
NH2CONH2
L- amino acid
28. Molecule can act as a base and as an acid
modulates fluidity and seeks to maintain optimal fluidity
stereoisomers
amphoteric
optical activity
29. Initial folding of proteins into shapes stabilized by H bonds btw amino and carboxyl groups of backbone
2 things about the cyclic form of a sugar as an acetal
glycerol
isoelectric point
secondary structure
30. 2 covalent bonds formed in proteins
peptide bonds and disulfide bonds
stereoisomers
Beta pleated sheet
histidine - arginine - lysine
31. Glycosidic linkage of lactose
galactose - beta -1 -4- glucose
tertiary structure
7.4
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
32. 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
only achiral amino acid
lipases
Cause of Amino acid separation in gel electrophoresis
33. Structure where H bonds occur btw residues distant from each other - or on a separate chain. backbone is extended rather than coiled
glucose - alpha -1 -2- fructose
isoelectric point
have amino group in their side chains
Beta pleated sheet
34. Unique feature of cysteine
has thiol group that allows it the form disulfide bond
ketose
D- glyceraldehyde
unsaturated fatty acid
35. Characteristic of basic amino acids
7.4
have amino group in their side chains
will have pI of 6
disulfide bond
36. 2 reasons why fats have more efficient energy stores than carbs
disulfide bond
packing and energy content
aldose
all acidic - basic - and polar amino acids
37. PH at which the amino acid has a net neutral charge
phospholipids
only amino acid that his a secondary amine
isoelectric point
anomeric carbon
38. Physiological pH
absolute configuration
7.4
Ka
primary structure
39. Nonpolar - hydrophobic amino acids
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
disulfide bond
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
L- amino acid
40. Sugar with an aldehyde at the first carbon position
aldose
modulates fluidity and seeks to maintain optimal fluidity
CH3COOH
galactose - beta -1 -4- glucose
41. Fatty acid w/ one or more double bonds in cis form predominately
amphoteric
unsaturated fatty acid
anomers
has thiol group that allows it the form disulfide bond
42. Characteristics of polar amino acids
epimers
C3H6O3 - with one chiral center
triacylglycerol
have an R group that is polar enough to H bond - but does no acts an acid or a base
43. Characteristics of acidic amino acids
has thiol group that allows it the form disulfide bond
have amino group in their side chains
have acidic carboxylic acid on side chains - w/ pKa around 4
L- configuration
44. (R) and (S) describe what?
starch
triacylglycerol
absolute configuration
secondary structure
45. Sugar with a carbonyl group at the 2 carbon position
ketose
glucose - alpha -1 -2- fructose
has thiol group that allows it the form disulfide bond
phospholipids
46. The amino acid sequence of a protein that is determined by peptide bond
primary structure
isoelectric point
only achiral amino acid
alpha helix
47. 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
have an R group that is polar enough to H bond - but does no acts an acid or a base
starch
isomers
48. Macromolecule that performs a variety of bodily functions and is composed of up to 20 different amino acids
2 things about the cyclic form of a sugar as an acetal
Proteins
packing and energy content
optical activity
49. What kind of lipids compromise the lipid bilayer?
all acidic - basic - and polar amino acids
amphipathic
phospholipids
only amino acid that his a secondary amine
50. Energy storage molecule of carbohydrates for plants
starch
triacylglycerol
maltase
all acidic - basic - and polar amino acids