Proteins Flashcards
(32 cards)
What are 3 examples of proteins?
Enzymes
Structural Proteins
Transport Proteins
What is an enzyme-like function?
Amelogenin acting as a scaffold for the mineralization of enamel
What is the typical composition of bone?
Mineral (Hydroxyapatite 50-70%) Protein (Mostly collagen; 20-40%) Non-collagen proteins (typically 1-2%) Lipids (3%) Water (5-10%)
The linkage between amino acids in protein is an _____ linkage?
amide
Two amino acids hooked together is a ______ bond
Peptide
Most proteins are ___ - ______ amino acids long
50 - 2000
Each protein sequence produces its own _______
Function
Omega
specifies protein backbone dihedral angle
Rotation around the peptide bond is restricted by ________. This simplifies deducing secondary structures.
Resonance
Alpha helices
Spiral staircases with amino acid steps
How many steps per alpha helice turn?
3.6 steps
What handed are alpha-helices?
right-handed
How do side chains project on alpha helices?
up and out
What is the distance between
0.15 nm
What is the distance between neighboring B strand residues?
0.35 nm
How do beta strands pair?
donor-acceptor backbone
B-strands are fully ______ conformations
extended
B - strands can align both _______ and ______ to form B- sheets
parallel
antiparallel
Silk fibroin is all __ sheet
Beta
Amyloid of _______ disease is almost all __ sheet
Alzheimer
Beta
__ - keratin (intracellular fibers of skin) is all __ helix (coiled-coil)
alpha
alpha
Myosin (protein for muscle contraction) is mostly __ helix
alpha
Some _______ - forming proteins are disordered before forming amyloid
amyloid
Amyloid
starch like but is actually a protein, presence in almost all neurogenerative diseases