Proteins Flashcards
Living organisms are
Carbon-based
Backbone of biological materials?
Hydrocarbons
Four kinds of macromolecules?
Proteins, Carbohydrates, Lipids, Nucleic acid
Proteins are
Combination of 20 amino acids
Isomers?
Same formula, different structure of compounds.
Cis: Same atoms on same side
Trans: Diff atoms on same side
Enantiomers?
Molecules that differ in spatial arrangement
Hydrolysis
Chemical reaction where water is used to break down chemical bonds
Proteins are held together by what type of bonds?
Peptide bonds (covalent)
Are D-amino acids or L-amino acids found in living things?
L-amino acids
The “capital letter” is the amino group of the 1st amino acid
N-terminus
The “period” is the carboxyl group of the last amino acid
C-terminus
Amino acids with positively charged, hydrophilic side chains
Arginine (R), Histidine (H), Lysine (K)
Amino acids with negatively charged, hydrophilic side chains
Aspartic acid (D), Glutamic acid (E)
Amino acids with polar, uncharged side chains
Serine (S), Threonine (T), Asparagine (N), Glutamine (Q), Tyrosine (Y)
Amino acids with non-polar hydrophobic side chains
Alanine (A), Isoleucine (I), Leucine (L), Methionine (M), Phenylalanine (F), Tryptophan (W), Valine (V)
Special cases
Cysteine (C), Glycine (G), Proline (P)
Cysteine may form what type of bond?
Disulphide bond b/c it has a SH group
Primary structure
The linear sequence of amino acids within a protein
Secondary Structure
Alpha-helix and Beta-pleated sheets
Tertiary Structure
3-dimensional configuration/ interaction of R-groups and the environment
Quaternary Structure
Interactions of sub-units
Condition that affect protein folding
High temperature, pH changes, High concentrations of polar molecules, nonpolar substances
Denaturation
Folded protein structure is broken down due to extreme conditions
Chaperones
Proteins that help prevent other proteins from binding to the wrong molecules
Heat Shock Proteins
Protect from being denatured and broken down
Hemoglobin has 4 polypeptide subunits folded together. This level of protein structure is called
Quaternary
Molecules containing an amino acids would be
A weak base
Which amino acid can form disulphide bonds?
Cystine (important in protein folding)
Importance of Glycine?
It is small and fits into tight corners
Why is Proline a special case?
It has a ring structure that limits hydrogen-bonding ability.
