Chapter 3- Protein Structure and Function

Directionαnal

________: There is an amino group- (NH3 +) on one end of the backbone and a carboxyl group- (Coo)- on the other.

dimensional shape

A proteins distinctive overall three- ________, or tertiary structure, results from interactions between residues that are brought together as the backbone bends and folds in space.

Enzyme

A protein that functions as a catalyst is called an

Flexibility

________: Although the peptide bond itself can not rotate because of its double- bond nature, the single bonds on either side of the peptide bond can rotate.

Polymers

________ that contain 50 or more amino acids are called polypeptides " (many- peptides)

Biochemists

________ refer to the unique sequence of amino acids in a protein as its primary structure.

macromolecular machines

In addition, cells contain ________: complexes of multiple proteins that assemble to carηr out a particular function.

COOH

________- a carboxyl functional group.

protein

The ________ is often used to describe any chain of amino acid residues.

R groups

Both polar and electrically charged ________ interact readily with water and are hydrophilic.

Cαtαlysis

________ are specialized to catalyze, or speed up, chemical reactions.

quaternary structure

The combination of polypeptides, referred to as subunits, gives some proteins ________.

central carbon

In all 20 amino acids, a(n) ________ atom (referred to as the carbon) bonds covalently to four different atoms or groups of atoms:

Nonpolar R groups

________ lack charged or highly electronegative atoms capable of forming hydrogen bonds with water.

R group

If the ________ in your amino acid does not have a negative charge, a positive charge, or an oxygen atom, then you are looking at a nonpolar amino acid, such as methionine.

R group

The ________, or side chain, represents the part of the amino acid core structure that makes each of the 20 different amino acids unique.

R-group orientαfion

The side chains of each residue extend out from the backbone, making it possible for them to interact with each other and with water

Directionαnal

There is an amino group (-NH3 +) on one end of the backbone and a carboxyl group (-Coo-) on the other

Flexibility

Although the peptide bond itself cannot rotate because of its double-bond nature, the single bonds on either side of the peptide bond can rotate

In addition, cells contain macromolecular machines

complexes of multiple proteins that assemble to carηr out a particular function

Hydrophilic

Both polar and electrically charged R-groups interact readily with water and are

Hydrophobic

Nonpolar R-groups lack charged or highly electronegative atoms capable of forming hydrogen bonds with water.

Peptide bond

The C-N covalent bond that results from this condensation reaction is called

oligopeptide

Generally, when fewer than 50 amino acids are linked together in this way, the resulting polymer is called an

Polypeptides

Polymers that contain 50 or more amino acids are called

Primary structure

Biochemists refer to the unique sequence of amino acids in a protein as its

Macromolecular machines

complexes of multiple proteins that assemble to carry out a particular function.