Chapter 3: Biologically Important Molecules Flashcards
Glycine
Gly (G) [Nonpolar]
Alanine
Ala (A) [Nonpolar]
Valine
Val (V) [Nonpolar]
Methionine
Met (M) [Nonpolar]
Leucine
Leu (L) [Nonpolar]
Isoleucine
Ile (I) [Nonpolar]
Proline
Pro (P) [Nonpolar]
Phenylanine
Phe (F) [Nonpolar]
Tryptophan
Trp (W) [Nonpolar]
Serine
Ser (S) [Polar]
Threonine
Thr (T) [Polar]
Asparagine
Asn (N) [Polar]
Glutamine
Gln (Q) [Polar]
Cysteine
Cys (C) [Polar]
Tyrosine
Tyr (Y) [Polar]
Aspartic Acid (Aspartate)
Asp (D) [electrically charged, NEGATIVELY charged at pH 7]
Glutamic Acid (Glutamate)
Glu (E) [electrically charged, NEGATIVELY charged at pH 7]
Histidine
His (H) [electrically charged, listed as positived charged at pH 7] BUT, technically Histidine can act as BASE and ACID.
Arginine
Arg (R) [electrically charged, POSITIVELY charged at pH 7]
Lysine
Lys (K) [electrically charged, POSITIVELY charged at pH 7]
What is special about the amino acid Proline?
It plays an important roles in turns . This is due to the fact proline is rigid and results in a kink in the peptide strand
2 common types of bonds between amino acids in proteins
1) the peptide bonds that link amino acids together into polypeptide chains
2) disulfide bridges between cysteine R groups
Polypeptides are formed by linking
amino acids together in peptide bonds
A peptide bond is formed between
the carboxyl group of one amino acid and the α amino group of another amino acids with the loss of water
Backbone of the polypeptide
In a polypeptide chain, the N-C-C-N-C-C pattern formed from the amino acids is known as the backbone of the polypeptide
Residue
An individual amino acids is termed a residue when it is part of a polypeptide chain
Thermodynamics states that ________ must decrease for a reaction to proceed spontaneously
free energy
proteolysis / proteolytic cleavage
hydrolysis of a protein by another protein
proteolytic enzyme (protease)
protein that does the cutting
The disulfide bond (Cysteine)
Cysteine is an amino acid that has a reactive thiol (SH) in its side chain. The thiol of one cysteine can react with the thiol of another cysteine to make a covalent sulfur-sulfur bond known as a disulfide bond. Cysteines can make this bond in same or different polypeptide chains. The disulfide bridge plays an important role in stabilizing tertiary protein structures. When cysteine is disulfide bonded to another cysteine residue it turns into cystine