Exp 2.1: Proteins, Structure Levels, Classifications Flashcards
most abundant biomolecule in all cells and all parts of a cell
proteins
proteins are biopolymers of?
amino acids
2 ways an amino acid links to another
- peptide bond
- condensation
Identify the level of protein structure:
sequence of amino acid residues
primary structure
Identify the level of protein structure:
regular, repeating folding patterns (H-bonding)
secondary structure
Identify the level of protein structure:
α-helix and β-pleated sheets
secondary structure
Identify the structure:
rod-like structure
N-H to C=O
H-bonds parallel to axis
typically amphiphilic
α-helix
Identify the structure:
polypeptide chains: side-by-side
H-bonds between chains
parallel or antiparallel
more stable
β-pleated sheets
Identify the level of protein structure:
overall folding of domains;
folding of protein segments in 3D
tertiary structure
Identify the level of protein structure:
interaction between different polypeptide chains to produce an oligomeric structure
quaternary structure
2 classifications of proteins according to composition
- simple proteins
- conjugated proteins
Identify the type of protein according to composition:
yield only amino acids upon hydrolysis;
primary structure only
simple proteins
Identify the type of protein according to composition:
simple proteins + non-protein substances
conjugated proteins
2 classifications of proteins according to shape
- globular proteins
- fibrous proteins
Identify the type of protein according to shape:
polypeptide chain/s folded into spherical shape
globular proteins
Identify the type of protein according to shape:
polypeptide chain/s arranged in long strands or sheets
fibrous proteins
Determine purpose:
globular proteins
fibrous proteins
globular proteins: functional purposes
fibrous proteins: structural support
Determine solubility:
globular proteins
fibrous proteins
globular proteins: soluble in aqueous system
fibrous proteins: water insoluble
concentration of protein in a saturated solution that is in equilibrium in the solid phase
protein solubility
Determine solubility:
albumins (plasma)
soluble in water and dilute aqueous solutions
Determine solubility:
globulins (serum)
soluble in dilute salt solutions
insoluble/ sparingly soluble in water
Determine solubility:
glutelins (flour)
soluble in dilute solutions of acids and bases
insoluble in neutral solvents
Determine solubility:
prolamins (protein storage in plants)
soluble in 50-90% alcohol
insoluble in water, neutral solvents, or absolute alcohol
Prolamins are abundant in __________.
proline
Determine solubility:
albuminoids/scleroproteins
(albumin-like)
insoluble in most ordinary solvents
