Amino Acids (General) Flashcards
Name the 6 aliphatic amino acids (name & 3-letter)
Glycine = Gly Alanine = Ala Proline = Pro (cyclic) Valine = Val Leucine = Leu Isoleucine = Ile
Name the 3 aromatic amino acids (name & 3-letter)
Tyrosine = Tyr Phenylalanine = Phe Tryptophan = Trp
What does aliphatic mean?
Non-polar
Name the 4 uncharged polar amino acids (name & 3-letter)
Asparagine = Asn Glutamine = Gln Serine = Ser Threonine = Thr
Name the 3 sulfur-containing amino acids
Methionine = Met Cysteine = Cys
Name the 5 charged amino acids?
Aspartate = Asp Glutamate = Glu Arginine = Arg Lysine = Lys Histidine = His
What is the only secondary amino acid?
Proline
What are L- and D- amino acids called relative to each other?
Stereoisomers, chiral
How are amino acids classified?
Charge, Size, Hydrophobicity/Polarity
What process is used for signaling purposes?
Phosphorylation
By what are proteins encoded?
Genes
How does a peptide bond influence the structure of a protein?
A resonance structure forms, creating partial double bonds, causing the molecules of the protein to lie in a single plain.
Where does rotation occur in a protein molecule?
Around the alpha carbon via angles phi and psi
Where are phi and psi located?
Adjacent to amine group and carbonyl group, respectively
Talk about the favorability of phi and psi?
Trans is more favorable than cis
What is a zwitter ion?
Neutral molecule that has a + and - charge
What is dissociation?
Loss of a proton during titration
Define Ka
Quantitative measure of the strength of an acid in solution. Quotient of concentration of acid-base in solution.
Ka = [H+][A-]/[HA]
Difference between pH and pKa
pH: Concentration of H+ ions in solution
pKa: How much an acid wants to dissociate in a solution
When does pH = pKa
[A-]/[HA] = 1, log(1) = 0
Write out Henderson-Hasselbach
pH = pKa + log([A-]/[HA])
How many amino acids are primary amino acids?
19/20
Which one is a secondary amino acid?
Proline
How many amino acids are alpha amino acids? What does alpha mean?
20/20; alpha describes the carbon on which the amine group and the COOH group is attached
When does chirality occur?
When a carbon has four different groups coming off of it.
What kind of configuration do amino acids have in the body?
L-configuration
How are amino acids linked?
Peptide bonds: Amide linkage + H2O
What is Ka?
Dissociation constant:
Ka = ([H+][A-])/[HA]
Does a stronger acid dissociate more or less than a weaker acid? Describe this using an equilibrium equation.
Dissociates more.
Equilibrium equation shifts more to the right
Define pKa mathematically
pKa = log(1/Ka)
What is a cause that results in more than 20 amino acids (more like 100s) in the body?
Modifications (phosphorylation, methylation, glycosylation, etc.)
What is the function of hemoglobin?
Oxygen transport protein
What are the different chains of hemoglobin?
alpha, beta, gamma, zeta
What does myoglobin do?
Protein that stores O2
What defines functions of proteins?
amino acids
Draw/describe what happens during a peptide bond
Carboxyl O- and H2 from NH3+ condense and NH forms amide bond with carboxyl carbon
Write Henderson-Hasselbach for bicarbonate system
pH = 6.1 + log([HCO3-]/(0.03*pCO2))
What does the bicarbonate system do?
Acts as the buffer system as lungs dispose of CO2. Can work along with phosphate buffer
What is the average molecular weight of an amino acid? What would be the MW of an AA that is 10 AA long?
110 g/mol; 1100 g/mol
