Proteins Flashcards
How many proteinogenic amino acids are there? How many of them are essential?
21 AAs, 9 of which are essential
Is plant or animal protein % higher?
animal
What are the 4 components of an amino acid?
- animo terminal (amino group)
- carboxyl terminal (carboxylic acid group)
- alpha-carbon
- side chain (different for all AAs)
What are enantiomers?
structures that have only 1 difference
What are Zwitterions?
the same AA, but at different pHs (COO- vs COOH, etc.)
the only thing that differs between AAs is…
side chain
“protein” refers to the…
(in terms of structure)
3D structure
“peptide” refers to the…
(in terms of structure)
2D structure
are “protein” and “peptide” interchangable terms?
Nope
What kind of bond forms between 2 AAs?
peptide / amide bond
how are peptide bonds formed?
condensation reactions – loss of water
how are peptide bonds broken?
hydrolysis reaction – addition of water
what is a primary structure?
the sequence of AAs
what is a secondary structure?
the backbone structure (alpha-helix vs beta-sheet)
what is a tertiary structure?
3D arrangement
What is a quaternary structure?
≥ 2 tertiary structures together (subunits)
What does it mean when a proteins is in a native state?
its normal and fine
What does it mean when a proteins is in a denatured state?
impaired protein structure and function
Whats a dipeptide?
2 AAs joined by a peptide bond
Whats a tripeptide?
3 AAs joined by peptide bonds
Whats a oligopeptide?
~ 50 AAs joined by by peptide bonds
whats a polypeptide?
> 50 AAs joined by peptide bonds
What are the Basic AAs?
(For bonus points, what puts them in this category, and are they polar or non-polar)
Lysine, Arginine, Histadine
(they have a positive charge, and are polar)
What are the Acidic AAs?
(For bonus points, what puts them in this category, and are they polar or non-polar)
Aspartate, Glutamate, Asparagine, Glutamine
(they have a negative charge, and are polar)
What are the Hydroxylated AAs?
(For bonus points, what puts them in this category, and are they polar or non-polar)
Serine, Threonine (technically also Tyrosine)
(have an OH-group on the side chain, and are polar)
What are the Neutral AAs?
(For bonus points, what puts them in this category, and are they polar or non-polar)
Glycine, Alanine
(have no charge on the side chain, and are non-polar)