Amino Acids, Lecture (sept 18 2024) (L4) Flashcards
Is cystine polar or non=polar?
Some Sources claim it as nonpolar, but it can be argued as both
Is methyl hydrophilic or hydrophobic?
phobic
Most simple amino acid structure?
glycine
R group of methionine?
C-C-S-C
CH2
R group of threonine?
C-C
|OH
like valine but with one OH group
three things, 1 OH
R group of tyrosine?
C-Phenyl +OH (group at end)
Phenylaline + an OH group
Which is the most flexible amino acid?
Glycine, because it only has the R group as Hydrogen
Is glycine hydrophobic or hydrophillic?
Hydrophobic
Which is more polar? Alanine vs. serine?
Serine, because it has an OH group
What makes cysteine unique?
It’s SH group allows for it to create disulfide bonds between other cysteine atoms
C-S-S-C
Which amino acid is not considered an amino but an imino acid? Why?
Proline
Nitrogen is a secondary amine group
Unique characteristic about proline?
Very rigid, because of bond
Bulkiest amino acid?
Tryptophan (has 2 rings)
Which amino acids have aromatic side chains?
tyrosine, phenylalanine, tryptophan
What pH is the amino acids side chainscharged ?
pH is around 7.4
Do peptide bonds have any rotation?
No
What is a peptide bond?
the bond that connects 2 amino acids
How is a polymer of an amino acid made?
the Carboxyl carbon of a.a#1 connects to the Nitrogen of a.a#2. H2O is a product (cuz O- group and H are lost)
Polypeptide definition
any chain of
amino acids linked to one
another via peptide bonds
Protein definition
usually a longer
peptide which has folded into a
unique 3D shape and with a
defined function
length of a protein
100 to 1000 amino acids
Protein vs. polypeptide?
Protein: 3D structure and has a defined function
Peptide:
pKa of carboxyl in aspartic acid?
3.9
pKa of carboxyl in glutamic acid?
4.3
