Lecture 2 DA Flashcards
According to the DL system, what are most proteins/amino acids in the human body?
L form
Bacterial walls can have D proteins hence their toxicity.
Antibiotics are based off D proteins/amino acids.
What is an enantiomer?
Mirror images, non-imposable
What is hydropathy?
Activation energy needed to pull a molecule from a hydrophobic phase to water.
What happens if the hydropathy of a molecule is positive? What about negative?
Positive - hydrophobic
Negative - hydrophilic
What is the molecular weight of a free amino acid? What about in proteins? Why the difference?
Free - 128
Protein - 110
Due to the loss of water in condensation.
What are the non-polar, aliphatic amino acids (7)?
Gycine Alanine Proline Valine Leucine Isoleucine Methionine
What are the aromatic amino acids (3)?
Phenylalanine
Tyrosine
Tryptophan
What are the positively charged amino acids (3)?
Lysine
Arginine
Histidine
What are the negatively charged amino acids (2)?
Aspartate
Glutamate
What is cystine?
Polymer of cysteine, forms a disulphide bridge.
What is the most common way to regulate proteins?
Phosphorylation
Name 2 amino acid like structures not found in proteins.
Orthonin
Citrulline
What wavelength do aromatic structures absorb?
280nm
What is amphoteric?
Dual acid-base behaviour, amino acids are amphoteric.
What form do amino acids exist at their pI?
Zwitterionic form, in most cases
