Lecture 8 Flashcards
(18 cards)
measures differences in the molar absorption of left-handed vs right-handed circularly polarized light
circular dichromism (CD) spectroscopy
Tertiary structures are stabilized by _____
non-covalent interactions between amino acid R groups; largely hydrophobic effect and polar interactions, can be stabilized by disulfide bonds
Contain several types of secondary structures; tend to be enzymes and regulatory proteins
Globular protein
Largely single type of secondary structure; provide support, shape, and protection
fibrous proteins
Fibrous proteins are _____ due to high concentrations of hydrophobic residues
H2O insoluble
Two _____ helices wrap about each other to form a left-handed supertwisted coiled coil
alpha-keratin
protein found in connective tissue; left-handed helix; three helices supertwist to form a right-handed triple helix
collagen
4 types of amino acids found in collagen are…
Gly, Ala, Pro, 4-Hyp
Keratin is rich in which residues?
Hydrophobic residues: Ala, Val, Leu, Ile, Met, Phe
Main protein in silk; formed by antiparallel beta-sheets
Fibroin
Fibroin is mainly composed of which residues?
Ala and Gly
Composed of different motifs folded together
Globular proteins
part of a polypeptide chain that is independently stable or could undergo movements as a single entity
domain
Combination of two or more tertiary units
Quaternary structure
multisubunit protein
oligomer
Quaternary structure made up of the same polypeptides
homodimer
Quaternary structure made up of different polypeptides
heterodimer
_____ contain long stretches of regular secondary structure
Fibrous proteins
