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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. Initial folding of proteins into shapes stabilized by H bonds btw amino and carboxyl groups of backbone
secondary structure
saturated fatty acid
quaternary structure
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
2. Carbon that in linear form has a carbonyl - or in cyclic form has a hemiacetal or an acetal
have acidic carboxylic acid on side chains - w/ pKa around 4
anomeric carbon
Proteins
primary structure
3. Characteristic of basic amino acids
have amino group in their side chains
7.4
NH2CONH2
3 things about the cyclic form of a sugar as a hemiacetal
4. Unique feature of proline
triacylglycerol
pyranose
packing and energy content
only amino acid that his a secondary amine
5. Glyceraldehyde
pyranose
1. presence of strong acids 2. proteolytic enzymes
C3H6O3 - with one chiral center
secondary structure
6. Glycosidic linkage of lactose
lactase
phospholipids
van der Waal forces of hydrophobic tails
galactose - beta -1 -4- glucose
7. Fatty acid structure
furanose
epimers
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
7.4
8. Adjacent polypeptide strands running in opposite directions in Beta pleated sheet structure
glucose - alpha -1 -2- fructose
L- amino acid
modulates fluidity and seeks to maintain optimal fluidity
antiparallel beta sheet
9. 4 causes of denaturation of proteins
C3H6O3 - with one chiral center
have an R group that is polar enough to H bond - but does no acts an acid or a base
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
modulates fluidity and seeks to maintain optimal fluidity
10. Nonpolar - hydrophobic amino acids
saturated fatty acid
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
optical activity
disulfide bond
11. What configuration do all naturally occuring amino acids have?
parallel beta sheet
L- configuration
packing and energy content
histidine - arginine - lysine
12. 3 physiological roles of lipids
L- amino acid
epimers
unsaturated fatty acid
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
13. Polar amino acids
glutamic acid and aspartic acid
serine - threonine - asparagine - glutamine - cysteine - tyrosine
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
phospholipids
14. 2 things that accelerate the rate of hydrolysis for peptide cleavage?
D- amino acid
1. presence of strong acids 2. proteolytic enzymes
glycogen
L- amino acid
15. Enzyme that hydrolyzes maltose into 2 glucose molecules?
peptide bond
cysteine and methionine
parallel beta sheet
maltase
16. 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
optical activity
histidine - arginine - lysine
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
17. PH at which the amino acid has a net neutral charge
isoelectric point
7.4
L- configuration
disulfide bond
18. Diastereomers that vary in the configuration of 1 chiral center
only amino acid that his a secondary amine
epimers
amphipathic
C3H6O3 - with one chiral center
19. 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
1. presence of strong acids 2. proteolytic enzymes
alpha helix
addition of water across of a bond
antiparallel beta sheet
20. 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)
have acidic carboxylic acid on side chains - w/ pKa around 4
CH3COOH
quaternary structure
packing and energy content
21. Energy storage molecule of carbohydrates for animals
quaternary structure
glycogen
glucose - alpha -1 -4- glucose
secondary structure
22. Histidine
unsaturated fatty acid
glycogen
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
glucose - alpha -1 -4- glucose
23. Amino group placed on the left of a fischer projection is a?
D- amino acid
L- amino acid
glycerol
glutamic acid and aspartic acid
24. Molecule can act as a base and as an acid
serine - threonine - asparagine - glutamine - cysteine - tyrosine
amphoteric
Beta pleated sheet
glutamic acid and aspartic acid
25. Enzymes that hydrolyze fats
7.4
glycogen
lipases
pyranose
26. D and L describe what?
all acidic - basic - and polar amino acids
the basic precursor of the molecule (L or D glyceraldehyde)
antiparallel beta sheet
saturated fatty acid
27. Fatty acid w/ one or more double bonds in cis form predominately
C3H6O3 - with one chiral center
phospholipids
unsaturated fatty acid
2 things about the cyclic form of a sugar as an acetal
28. Acidic amino acids
glutamic acid and aspartic acid
have an R group that is polar enough to H bond - but does no acts an acid or a base
serine - threonine - asparagine - glutamine - cysteine - tyrosine
glucose - beta -1 -4- glucose
29. Sulfur containing amino acids
anomeric carbon
optical activity
cysteine and methionine
NH2CONH2
30. Hydrolysis
has thiol group that allows it the form disulfide bond
addition of water across of a bond
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
maltase
31. Rule for all amino acids that are nonbasic and nonacidic pertaining to pI value?
alpha helix
peptide bond
will have pI of 6
parallel beta sheet
32. Name for 6 membered ring
D- glyceraldehyde
Cause of Amino acid separation in gel electrophoresis
all acidic - basic - and polar amino acids
pyranose
33. Fxn of cholesterol in the membrane?
pyranose
modulates fluidity and seeks to maintain optimal fluidity
long chain of unsubstituted alkanes that end in a carboxylic acid - making them amphipathic
disulfide bond
34. 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
maltase
3 things about the cyclic form of a sugar as a hemiacetal
peptide bonds and disulfide bonds
pI
35. Amino group placed on the right of a fischer projection is a?
Cause of Amino acid separation in gel electrophoresis
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
pI
D- amino acid
36. Epimers of sugars that vary in the configuration of their anomeric carbons
Beta pleated sheet
isoelectric point
glucose - beta -1 -4- glucose
anomers
37. Formula for urea
NH2CONH2
CH3COOH
galactose - beta -1 -4- glucose
addition of water across of a bond
38. Storage form of fatty acid that is composed of 3 esterified fatty acid to a glycerol molecule
primary structure
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
have an R group that is polar enough to H bond - but does no acts an acid or a base
triacylglycerol
39. Molecules with the same atoms - but different bonds
modulates fluidity and seeks to maintain optimal fluidity
L- amino acid
packing and energy content
isomers
40. Physiological pH
only achiral amino acid
7.4
pI
maltase
41. Hydrophobic and hydrophilic interactions btw amino acids more distant from each other on the polypeptide chain
all acidic - basic - and polar amino acids
tertiary structure
pyranose
7.4
42. 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
glucose - beta -1 -4- glucose
absolute configuration
alpha helix
43. Molecules with the same atoms and same bonds - but different bond geometries; can either be enantiomers or diastereomers
glycine - alanine - valine - methionine - leucine - isoleucine - proline - phenylalanine - tryptophan
isomers
all acidic - basic - and polar amino acids
stereoisomers
44. Enzyme that hydrolyzes lactose into galactose and glucose into
isomers
maltase
Characteristics of the peptide bond
lactase
45. What describes the affinity of functional groups for a proton?
the basic precursor of the molecule (L or D glyceraldehyde)
glucose - beta -1 -4- glucose
D- amino acid
Ka
46. PH at which positive and negative charges balance to form a zwitterion
lipases
peptide bond
pI
packing and energy content
47. Name for 5 membered ring
ketose
furanose
phospholipids
quaternary structure
48. Glycosidic linkage of maltose
C3H6O3 - with one chiral center
tertiary structure
basic amino acid has pKa at 6.5 - so it can either be protonated or deprotonated at physiological pH
glucose - alpha -1 -4- glucose
49. Characteristics of hydrophobic amino acids
1. presence of urea 2. extreme pH 3. extreme temperature 4. changes in salinity
1. form phospholipids of cellular membranes 2. store energy in adipose tissue 3. produce steroid hormones
parallel beta sheet
have alkyl or aromatic side chains and tend to associate w/ each other - rather than water
50. What stabilizes lipid bilayer?
tertiary structure
lactase
triacylglycerol
van der Waal forces of hydrophobic tails