2.1.1 Structure and Properties of Amino Acids

A zigzag structure that is perpendicular to the direction of the protein chain.

Proline's cyclic structure provides the correct geometry for reverse turns, typically occurring as the second residue.

A common non-repetitive irregular secondary motif in antiparallel beta-sheets.

Polymers consisting of amino acids linked by covalent peptide bonds.

It is a regulatory component of the lactose synthase enzyme.

It reduces disulfide bridges to two sulfhydryl groups.

Hydrogen bonds involving hydroxyproline and hydroxylysine.

Polypeptide chains organized approximately parallel along a single axis, forming long fibers or large sheets.

The O2 affinity of hemoglobin decreases.

Structures resulting from the combination of alpha and beta strands, such as βαβ and αα.

Non-covalent interactions, including hydrogen bonding, hydrophobic interactions, and electrostatic attractions.

Biological functions of the protein.

It is 25,000 times greater for carbon monoxide than for oxygen.

Proximity of several side chains of like charges, such as lysine and arginine or glutamic and aspartic.

The 3D shapes of proteins with biological activity.

Globular proteins fold on themselves to produce a spherical shape and are generally soluble in water.

1 torr partial pressure of O2.

A method used to model proteins with the same fold as known structures.

The order in which amino acids are covalently linked together.

All three individual collagen chains are helices that differ from the alpha-helix.

The arrangement of subunits with respect to one another.

They stabilize the arrangement of the polypeptide chain.

Oxygenated hemoglobin undergoes conformational changes that affect its function.

BPG plays a role in the supply of O2 to the growing fetus.

Type I, where the side chain lies outside the loop, and Type II, where the side chain is rotated 180 degrees and lies inside the loop.

They are associated with a particular function.

Breakdown of noncovalent interactions due to heat, pH changes, detergents, urea, and beta-mercaptoethanol.

100% saturation.

Parallel and antiparallel.

They become cross-linked by covalent bonds formed by reactions of lysine and histidine residues.

A repetitive supersecondary structure created when beta sheets fold back on themselves.

The 3D arrangement of all atoms in a molecule, including side chains and prosthetic groups.

Proteins that consist of more than one polypeptide chain, called subunits.

The effect of H+ on reducing the O2 affinity of hemoglobin.

BPG binding reduces the oxygen-binding capacity of hemoglobin.

Searching databases for sequence homology.

An algorithmic process predicting tertiary structure from primary amino acid sequence.

Keratin in hair and wool, and collagen in connective tissue.

From the N-terminal end to the C-terminal end.

A protein expressed exclusively in the lactating mammary gland.

The 3D arrangement of all atoms in a protein, including side chains and prosthetic groups.

Hydrogen bonding in the polypeptide backbone.

X-ray crystallography and nuclear magnetic resonance spectroscopy.

It binds oxygen in the bloodstream.

It disrupts the alpha-helix due to its cyclic structure and restricts rotation.

When one O2 is bound, it becomes easier for the next O2 to bind.

To fold a primary amino acid sequence into a protein structure for novel function and behavior.

Alpha-helix and beta-pleated sheets.

The ordered 3D arrangement in space of the backbone atoms in a polypeptide chain.

Consists of a single polypeptide chain of 153 amino acid residues and a heme prosthetic group.

They restrict folding patterns available to polypeptide chains.

Myoglobin is for oxygen storage, while hemoglobin is for oxygen transport.