Exam 2: Proteins Flashcards
What elements make up proteins?
C, H, O, N, and small amounts of other elements like S
Monomers of proteins?
Amino acids
Compound composed of 2-49 amino acids
Peptide
Compound composed of 50+ amino acids
Polypeptide
Structure of Amino Acids
Amino Group (NH2), Carboxyl Group (COOH), H, Side chain
What charge is the amino group?
+
What charge is the carboxyl group?
-
How many side chains are there?
20
Four types of side chains
Acidic, basic, uncharged polar (hydrophilic), nonpolar (hydrophobic)
If the side chain has a negative charge
Acidic
If the side chain has a positive charge
Basic
If the side chain has an oxygen
Uncharged polar (hydrophilic)
Which amino acid only has a hydrogen for its side chain
Glycine
Which amino acid is ringed
Proline
Which amino acid has a sulfhydryl group
Cysteine
What bond connects amino acids for polymerization?
peptide bond
How does a peptide bond form?
Dehydration synthesis, oxygen of carboxyl group and hydrogens of amino group are removed
3 characteristics of peptide bond backbones
R-group orientation, directionality (N to C), flexibility
Four levels of protein structure
Primary, Secondary, Tertiary, Quaternary
What is primary structure
Amino acid sequence
What is secondary structure
Hydrogen bonding between O of carboxyl group and H of amino group, forms either alpha-helix or beta-pleated sheet
What is tertiary structure
Folding of secondary structures…hydrogen bonding, ionic bonding, hydrophobic / van der Waals interactions, and disulfide bonds form 3D shape
What is quaternary structure
Subunits interact to form a single structure
