Amino acid features Flashcards
Arginine (Arg, R)
Positively charged, polar.
Contains a guanidinium group; precursor for nitric oxide (NO) synthesis
Alanine (Ala, A)
Feature: Nonpolar, aliphatic.
Special Feature: One of the simplest amino acids, often involved in the alanine-glucose cycle for energy production.
Asparagine (Asn, N)
Feature: Polar, uncharged.
Special Feature: Contains an amide group; important for N-linked glycosylation in proteins
Aspartic Acid (Asp, D)
Feature: Negatively charged, polar.
Special Feature: Plays a role in the urea cycle and gluconeogenesis.
Cysteine (Cys, C)
Feature: Polar, uncharged.
Special Feature: Contains a thiol group; forms disulfide bonds critical for protein structure.
Glutamine (Gln, Q)
Feature: Polar, uncharged.
Special Feature: Important for nitrogen transport and metabolism; precursor for nucleotides.
Glutamic Acid (Glu, E)
Feature: Negatively charged, polar.
Special Feature: Acts as a neurotransmitter in the central nervous system.
Glycine (Gly, G)
Feature: Nonpolar, aliphatic.
Special Feature: The smallest amino acid; often found in tight turns of protein structures.
Histidine (His, H)
Feature: Positively charged, polar.
Special Feature: Contains an imidazole ring; can act as a proton donor or acceptor at physiological pH.
Isoleucine (Ile, I)
Feature: Nonpolar, aliphatic.
Special Feature: Branched-chain amino acid; essential for muscle metabolism.
Leucine (Leu, L)
Feature: Nonpolar, aliphatic.
Special Feature: Branched-chain amino acid; stimulates protein synthesis via mTOR pathway.
Lysine (Lys, K)
Feature: Positively charged, polar.
Special Feature: Contains an ε-amino group; important for histone modification and crosslinking in collagen.
Methionine (Met, M)
Feature: Nonpolar, aliphatic.
Special Feature: Contains a sulfur atom; the start codon (AUG) in protein synthesis.
Phenylalanine (Phe, F)
Feature: Aromatic, nonpolar.
Special Feature: Precursor for tyrosine and neurotransmitters like dopamine and norepinephrine.
Proline (Pro, P)
Feature: Nonpolar, aliphatic.
Special Feature: Contains a cyclic structure; disrupts secondary structures like α-helices.
Serine (Ser, S)
Feature: Polar, uncharged.
Special Feature: Contains a hydroxyl group; involved in phosphorylation and signal transduction.
Threonine (Thr, T)
Feature: Polar, uncharged.
Special Feature: Contains a hydroxyl group; important for glycosylation of proteins.
Tryptophan (Trp, W)
Feature: Aromatic, nonpolar.
Special Feature: Precursor for serotonin and melatonin; contains an indole ring.
Tyrosine (Tyr, Y)
Feature: Aromatic, polar.
Special Feature: Precursor for dopamine, epinephrine, and thyroid hormones; can be phosphorylated.
Valine (Val, V)
Feature: Nonpolar, aliphatic.
Special Feature: Branched-chain amino acid; important for muscle repair and growth.
Nonpolar, Aliphatic
Alanine (Ala), Valine (Val), Leucine (Leu), Isoleucine (Ile), Methionine (Met), Proline (Pro), Glycine (Gly).
Aromatic
Phenylalanine (Phe), Tyrosine (Tyr), Tryptophan (Trp).
Positively Charged (Basic)
Lysine (Lys), Arginine (Arg), Histidine (His).
Negatively Charged (Acidic)
Aspartic Acid (Asp), Glutamic Acid (Glu).
