ACS Biochem Exam
How many amino acids are there? - ANSWER: over 500, but 22 alpha-amino acids are
incorporated into proteins and only these 22 appear in the genetic code of life
What are the 9 essential amino acids? - ANSWER: histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, and valine
What are the 5 nonessential amino acids? - ANSWER: alanine, asparagine, aspartic
acid, glutamic acid, and serine
What are the 6 conditional amino acids? - ANSWER: arginine, cysteine, glutamine,
glycine, proline, and tyrosine
Definition of amino acid - ANSWER: organic molecule that is made up of a basic amino
group (−NH2), an acidic carboxyl group (−COOH), and an organic R group (or side
chain) that is unique to each amino acid
Amino acids are the building blocks of what? - ANSWER: proteins
ala - ANSWER: alanine, A; aliphatic, nonpolar, neutral at pH 7.4; small
arg - ANSWER: arginine, R; fixed cation, basic polar, positive at pH 7.4; hydrophilic
asn - ANSWER: asparagine, N; amide, polar, neutral at pH 7.4; hydrophilic
asp - ANSWER: aspartic acid or aspartate, D; anion, Bronsted base, negative at pH 7.4;
hydrophilic
cys - ANSWER: cysteine, C; thiol, Bronsted acid, neutral at pH 7.4
gln - ANSWER: glutamine, Q; amide, polar, neutral at pH 7.4; hydrophilic
glu - ANSWER: glutamic acid or glutamate, E; anion, Bronsted base, negative at pH
7.4; hydrophilic
gly - ANSWER: glycine, G; achiral, aliphatic, nonpolar, neutral at pH 7.4; small
,his - ANSWER: histidine, H; cationic, Bronsted acid and base, positive 10% and neutral
90% at pH 7.4; aromatic, hydrophilic
ile - ANSWER: isoleucine, I; aliphatic, nonpolar, neutral at pH 7.4; hydrophobic
leu - ANSWER: leucine, L; aliphatic, nonpolar, neutral at pH 7.4; hydrophobic
lys - ANSWER: lysine, K; cation, Bronsted acid, positive at pH 7.4; hydrophilic
met - ANSWER: methionine, M; thioether, nonpolar, neutral at pH 7.4; hydrophobic,
aliphatic
phe - ANSWER: phenylalanine, F; aromatic, nonpolar, neutral at pH 7.4; hydrophobic
pro - ANSWER: proline, P; cyclic, nonpolar, neutral at pH 7.4; small
ser - ANSWER: serine, S; hydroxylic, polar, neutral at pH 7.4; small, hydrophilic
thr - ANSWER: threonine, T; hydroxylic, polar, neutral at pH 7.4; has 2 chiral centers;
hydrophilic
trp - ANSWER: tryptophan, W; aromatic, nonpolar, neutral at pH 7.4; hydrophobic
tyr - ANSWER: tyrosine, Y; aromatic, Bronsted acid, neutral at pH 7.4; hydrophobic
val - ANSWER: valine, V; aliphatic, nonpolar, neutral at pH 7.4; hydrophobic
The alpha carbon is stereogenic in all alpha-amino acids except ______ - ANSWER:
glycine
All chiral proteogenic amino acids have the _____ configuration - ANSWER: L: they are
all left handed enantiomers
sec - ANSWER: selenocysteine, U; rare amino acid not directly encoded by DNA but is
incorporated into proteins via the ribosome
pyl - ANSWER: pyrrolysine, O; rare amino acid not directly encoded by DNA but is
synthesized into protein by ribosomes
polypeptide - ANSWER: unbranched chain of amino acids
aliphatic - ANSWER: relating to organic compounds in which carbon atoms form open
chains, not aromatic rings
types of organelles - ANSWER: nucleus, mitochondrion, smooth endoplasmic reticulum
(SER), rough endoplasmic reticulum (RER), Golgi apparatus, peroxisome, lysosome
, supramolecular assemblies - ANSWER: ribosomes, enzyme complexes, contractile
systems, microtubules
macromolecules - ANSWER: nucleic acids, proteins, polysaccharides, lipids
building blocks - ANSWER: nucleotides, amino acids, monosaccharides, fatty acids,
glycerol
metabolic intermediates - ANSWER: pyruvate, citrate, malate, glyceraldehyde 3-
phosphate
precursors form the environment - ANSWER: carbon dioxide, water, ammonia, nitrogen
pyrimidines - ANSWER: uracil, thymine, cytosine
purines - ANSWER: adenine, guanine
nucleotides - ANSWER: basic building blocks or the nucleic acids DNA and RNA; made
up of a nitrogen-containing base, a phosphate group, and a sugar molecule
nucleotides in DNA - ANSWER: Adenine, Guanine, Thymine, Cytosine
nucleotides in RNA - ANSWER: Adenine, Guanine, Uracil, Cytosine
carbohydrates and their empirical formula - ANSWER: primarily a combination of
carbon, hydrogen and oxygen; empirical formula (CH2O)n
monosaccharides - ANSWER: simple sugars/simplest carbohydrates; building blocks
(monomers) for synthesis of polymers or complex carbohydrates; classified based on
the number of carbons in the molecule
when are monosaccharides most stable - ANSWER: monosaccharides of 4 or more
carbon atoms are typically more stable when they adopt cyclic structures. this results
from a chemical reaction between functional groups on opposite ends of the sugar's
flexible carbon chain (namely the carbonyl group and a relatively distant hydroxyl group)
three types of disaccharides - ANSWER: glucose, sucrose, maltose
disaccharides - ANSWER: two monosaccharide molecules chemically bonded together
with glycosidic bonds (covalent bonds formed between hydroxyl groups of the two
saccharide molecules)
what type of sugar is maltose - ANSWER: grain, made of two glucose molecules
How many amino acids are there? - ANSWER: over 500, but 22 alpha-amino acids are
incorporated into proteins and only these 22 appear in the genetic code of life
What are the 9 essential amino acids? - ANSWER: histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, and valine
What are the 5 nonessential amino acids? - ANSWER: alanine, asparagine, aspartic
acid, glutamic acid, and serine
What are the 6 conditional amino acids? - ANSWER: arginine, cysteine, glutamine,
glycine, proline, and tyrosine
Definition of amino acid - ANSWER: organic molecule that is made up of a basic amino
group (−NH2), an acidic carboxyl group (−COOH), and an organic R group (or side
chain) that is unique to each amino acid
Amino acids are the building blocks of what? - ANSWER: proteins
ala - ANSWER: alanine, A; aliphatic, nonpolar, neutral at pH 7.4; small
arg - ANSWER: arginine, R; fixed cation, basic polar, positive at pH 7.4; hydrophilic
asn - ANSWER: asparagine, N; amide, polar, neutral at pH 7.4; hydrophilic
asp - ANSWER: aspartic acid or aspartate, D; anion, Bronsted base, negative at pH 7.4;
hydrophilic
cys - ANSWER: cysteine, C; thiol, Bronsted acid, neutral at pH 7.4
gln - ANSWER: glutamine, Q; amide, polar, neutral at pH 7.4; hydrophilic
glu - ANSWER: glutamic acid or glutamate, E; anion, Bronsted base, negative at pH
7.4; hydrophilic
gly - ANSWER: glycine, G; achiral, aliphatic, nonpolar, neutral at pH 7.4; small
,his - ANSWER: histidine, H; cationic, Bronsted acid and base, positive 10% and neutral
90% at pH 7.4; aromatic, hydrophilic
ile - ANSWER: isoleucine, I; aliphatic, nonpolar, neutral at pH 7.4; hydrophobic
leu - ANSWER: leucine, L; aliphatic, nonpolar, neutral at pH 7.4; hydrophobic
lys - ANSWER: lysine, K; cation, Bronsted acid, positive at pH 7.4; hydrophilic
met - ANSWER: methionine, M; thioether, nonpolar, neutral at pH 7.4; hydrophobic,
aliphatic
phe - ANSWER: phenylalanine, F; aromatic, nonpolar, neutral at pH 7.4; hydrophobic
pro - ANSWER: proline, P; cyclic, nonpolar, neutral at pH 7.4; small
ser - ANSWER: serine, S; hydroxylic, polar, neutral at pH 7.4; small, hydrophilic
thr - ANSWER: threonine, T; hydroxylic, polar, neutral at pH 7.4; has 2 chiral centers;
hydrophilic
trp - ANSWER: tryptophan, W; aromatic, nonpolar, neutral at pH 7.4; hydrophobic
tyr - ANSWER: tyrosine, Y; aromatic, Bronsted acid, neutral at pH 7.4; hydrophobic
val - ANSWER: valine, V; aliphatic, nonpolar, neutral at pH 7.4; hydrophobic
The alpha carbon is stereogenic in all alpha-amino acids except ______ - ANSWER:
glycine
All chiral proteogenic amino acids have the _____ configuration - ANSWER: L: they are
all left handed enantiomers
sec - ANSWER: selenocysteine, U; rare amino acid not directly encoded by DNA but is
incorporated into proteins via the ribosome
pyl - ANSWER: pyrrolysine, O; rare amino acid not directly encoded by DNA but is
synthesized into protein by ribosomes
polypeptide - ANSWER: unbranched chain of amino acids
aliphatic - ANSWER: relating to organic compounds in which carbon atoms form open
chains, not aromatic rings
types of organelles - ANSWER: nucleus, mitochondrion, smooth endoplasmic reticulum
(SER), rough endoplasmic reticulum (RER), Golgi apparatus, peroxisome, lysosome
, supramolecular assemblies - ANSWER: ribosomes, enzyme complexes, contractile
systems, microtubules
macromolecules - ANSWER: nucleic acids, proteins, polysaccharides, lipids
building blocks - ANSWER: nucleotides, amino acids, monosaccharides, fatty acids,
glycerol
metabolic intermediates - ANSWER: pyruvate, citrate, malate, glyceraldehyde 3-
phosphate
precursors form the environment - ANSWER: carbon dioxide, water, ammonia, nitrogen
pyrimidines - ANSWER: uracil, thymine, cytosine
purines - ANSWER: adenine, guanine
nucleotides - ANSWER: basic building blocks or the nucleic acids DNA and RNA; made
up of a nitrogen-containing base, a phosphate group, and a sugar molecule
nucleotides in DNA - ANSWER: Adenine, Guanine, Thymine, Cytosine
nucleotides in RNA - ANSWER: Adenine, Guanine, Uracil, Cytosine
carbohydrates and their empirical formula - ANSWER: primarily a combination of
carbon, hydrogen and oxygen; empirical formula (CH2O)n
monosaccharides - ANSWER: simple sugars/simplest carbohydrates; building blocks
(monomers) for synthesis of polymers or complex carbohydrates; classified based on
the number of carbons in the molecule
when are monosaccharides most stable - ANSWER: monosaccharides of 4 or more
carbon atoms are typically more stable when they adopt cyclic structures. this results
from a chemical reaction between functional groups on opposite ends of the sugar's
flexible carbon chain (namely the carbonyl group and a relatively distant hydroxyl group)
three types of disaccharides - ANSWER: glucose, sucrose, maltose
disaccharides - ANSWER: two monosaccharide molecules chemically bonded together
with glycosidic bonds (covalent bonds formed between hydroxyl groups of the two
saccharide molecules)
what type of sugar is maltose - ANSWER: grain, made of two glucose molecules
