Amino Acids - Chapter 3 Flashcards
What is the general structure of an amino acid?
An amino acid has a central carbon (α-carbon) bonded to an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a unique side chain (R group).
What are the two forms of amino acids in biological systems?
Amino acids exist in two enantiomeric forms: L-form and D-form. Biological systems predominantly use L-form amino acids.
How is the side chain (R group) of an amino acid important?
The side chain (R group) determines the amino acid’s properties, such as its polarity, charge, size, and hydrophobicity or hydrophilicity.
What are the three main classifications of amino acids based on their side chains?
Amino acids can be classified as nonpolar (hydrophobic), polar (hydrophilic), and charged (acidic or basic).
List the amino acids with nonpolar, aliphatic side chains.
Glycine, alanine, valine, leucine, isoleucine, and proline.
Which amino acids contain aromatic side chains?
Phenylalanine, tyrosine, tryptophan, and histidine
What are the amino acids with polar, uncharged side chains?
Serine, threonine, asparagine, glutamine, and cysteine.
Which amino acids are classified as acidic due to their side chains?
Aspartate and glutamate
Name the amino acids with basic side chains.
Lysine, arginine, and histidine.
What is the significance of the pKa values of the amino and carboxyl groups in amino acids?
The pKa values determine the ionization state of the amino acid at different pH levels, influencing its charge and interactions.
What is the concept of isoelectric point (pI) in amino acids?
The isoelectric point (pI) is the pH at which an amino acid has no net charge and exists predominantly in its zwitterionic form.
Why are amino acids important to protein structure?
Amino acids are the building blocks of proteins. Their sequence and chemical properties determine the protein’s structure and function, including primary, secondary, tertiary, and quaternary structures.
What is a peptide bond and how is it formed?
A peptide bond is a covalent bond formed between the carboxyl group of one amino acid and the amino group of another, releasing a molecule of water.
What is the significance of post-translational modifications of amino acids?
Post-translational modifications can alter protein function, stability, localization, and interactions, and include processes like phosphorylation, glycosylation, and acetylation.
How do amino acid side chains contribute to enzyme function?
Side chains can participate in substrate binding, catalysis, and stabilization of transition states, playing crucial roles in enzyme activity.
Is glycine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is alanine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is valine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is leucine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is isoleucine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is methionine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is phenylalanine hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is tryptophan hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is proline hydrophobic or hydrophilic? Is it charged?
hydrophobic, uncharged
Is serine hydrophobic or hydrophilic? Is it charged?
hydrophilic, uncharged
Is threonine hydrophobic or hydrophilic? Is it charged?
hydrophilic, uncharged
Is cysteine hydrophobic or hydrophilic? Is it charged?
hydrophilic, uncharged
Is tyrosine hydrophobic or hydrophilic? Is it charged?
hydrophilic, uncharged
Is asparagine hydrophobic or hydrophilic? Is it charged?
hydrophilic, uncharged
Is glutamine hydrophobic or hydrophilic? Is it charged?
hydrophilic, uncharged
Is aspartate hydrophobic or hydrophilic? Is it charged?
hydrophilic, acidic (charged)
Is glutamate hydrophobic or hydrophilic? Is it charged?
hydrophilic, acidic (charged)
Is lysine hydrophobic or hydrophilic? Is it charged?
hydrophilic, basic (charged)
Is arginine hydrophobic or hydrophilic? Is it charged?
hydrophilic, basic (charged)
Is histidine hydrophobic or hydrophilic? Is it charged?
hydrophilic, basic (charged)
What is the three-letter abbreviation for alanine?
Ala
What is the three-letter abbreviation for arginine?
Arg
What is the three-letter abbreviation for asparagine?
Asn
What is the three-letter abbreviation for aspartate?
Asp
What is the three-letter abbreviation for cysteine?
Cys
What is the three-letter abbreviation for glutamate?
Glu
What is the three-letter abbreviation for glutamine?
Gln
What is the three-letter abbreviation for glycine?
Gly
What is the three-letter abbreviation for histidine?
His
What is the three-letter abbreviation for isoleucine?
Ile
What is the three-letter abbreviation for leucine?
Leu
What is the three-letter abbreviation for lysine?
Lys
What is the three-letter abbreviation for methionine?
Met
What is the three-letter abbreviation for phenylalanine?
Phe
What is the three-letter abbreviation for proline?
Pro
What is the three-letter abbreviation for serine?
Ser
What is the three-letter abbreviation for threonine?
Thr
What is the three-letter abbreviation for tryptophan?
Trp
What is the three-letter abbreviation for tyrosine?
Tyr
What is the three-letter abbreviation for valine?
Val
What is the one-letter abbreviation for alanine?
A
What is the one-letter abbreviation for arginine?
R
What is the one-letter abbreviation for asparagine?
N
What is the one-letter abbreviation for aspartate?
D
What is the one-letter abbreviation for cysteine?
C
What is the one-letter abbreviation for glutamate?
E
What is the one-letter abbreviation for glutamine?
Q
What is the one-letter abbreviation for glycine?
G
What is the one-letter abbreviation for histidine?
H
What is the one-letter abbreviation for isoleucine?
I
What is the one-letter abbreviation for leucine?
L
What is the one-letter abbreviation for lysine?
K
What is the one-letter abbreviation for methionine?
M
What is the one-letter abbreviation for phenylalanine?
F
What is the one-letter abbreviation for proline?
P
What is the one-letter abbreviation for serine?
S
What is the one-letter abbreviation for threonine?
T
What is the one-letter abbreviation for tryptophan?
W
What is the one-letter abbreviation for tyrosine?
Y
What is the one-letter abbreviation for valine?
V
What are the abbreviations for alanine?
Ala and A
What are the abbreviations for arginine?
Arg and R
What are the abbreviations for asparagine?
Asn and N
What are the abbreviations for aspartate?
Asp and D
What are the abbreviations for cysteine?
Cys and C
What are the abbreviations for glutamate?
Glu and E
What are the abbreviations for glutamine?
Gln and Q
What are the abbreviations for glycine?
Gly and G
What are the abbreviations for histidine?
His and H
What are the abbreviations for isoleucine?
Ile and I
What are the abbreviations for leucine?
Leu and L
What are the abbreviations for lysine?
Lys and K
What are the abbreviations for methionine?
Met and M
What are the abbreviations for phenylalanine?
Phe and F
What are the abbreviations for proline?
Pro and P
What are the abbreviations for serine?
Ser and S
What are the abbreviations for threonine?
Thr and T
What are the abbreviations for tryptophan?
Trp and W
What are the abbreviations for tyrosine?
Tyr and Y
What are the abbreviations for valine?
Val and V
Which have ionization states influenced by pH?
Glutamate
Aspartate
Histidine
Arginine
Lysine
Serine
Cysteine
Tyrosine
Threonine
List all the charged amino acids.
Acidic: glutamate and aspartate
Basic: lysine, histidine, arginine
Which amino acid is this?
Glycine
Hydrophobic, uncharged
Which amino acid is this?
Alanine
Hydrophobic, uncharged
Which amino acid is this?
Valine
Hydrophobic, uncharged
Which amino acid is this?
Leucine
Hydrophobic, uncharged
Which amino acid is this?
Isoleucine
Hydrophobic, uncharged
Which amino acid is this?
Proline
Hydrophobic, uncharged
Which amino acid is this?
Methionine
Hydrophobic, uncharged
Which amino acid is this?
Phenylalanine
Hydrophobic, uncharged
Which amino acid is this?
Tyrosine
Hydrophilic, uncharged
Which amino acid is this?
Threonine
Hydrophilic, uncharged
Which amino acid is this?
Glutamate
Hydrophilic, acidic
Which amino acid is this?
Aspartate
Hydrophilic, acidic
Which amino acid is this?
Lysine
Hydrophilic, basic
Which amino acid is this?
Histidine
Hydrophilic, basic
Which amino acid is this?
Arginine
Hydrophilic, basic
Which amino acid is this?
Serine
Hydrophilic, uncharged
Which amino acid is this?
Glutamine
Hydrophilic, uncharged
Which amino acid is this?
Cysteine
Hydrophilic, uncharged
Which amino acid is this?
Asparagine
Hydrophilic, uncharged
Which amino acid is this?
Tryptophan
Hydrophobic, uncharged
How many essential amino acids are there?
9
List the essential amino acids.
phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, lysine, and leucine
PVT TIM HiLL