Ch. 4 Flashcards
How many different amino acids are used in making proteins?
20
Which parts of amino acids are involved in peptide bonds?
The amino group on one amino acid and the carboxyl group on the other
Which part of an amino acid gives it its unique properties?
The side chain
In a folded protein, the nonpolar (hydrophobic) amino acids tend to be:
tucked away inside the protein.
What provides the information necessary to specify the three-dimensional shape of a protein?
The protein’s amino acid sequence
The biological activity of a protein is determined by its:
Amino Acid Sequence
A protein can be unfolded by a process called:
denaturation
What hydrogen bonds have been found to stabilize a polypeptide’s folded shape?
- Hydrogen bonds between side chain atoms
- Hydrogen bonds between backbone atoms and side chain atoms
- Hydrogen bonds between backbone atoms
What is the best type of model for visualizing the surface of a protein?
The space-filling model
Why are /alpha helices and /beta sheets common folding patterns in polypeptides?
Amino acid side chains are not involved in forming the hydrogen bonds, allowing many different sequences to adopt these folding patterns.
Those portions of a transmembrane protein that cross the lipid bilayer usually consist of which structures?
An /alpha helix with mostly nonpolar side chains
The two types of /beta sheets are:
parallel /beta sheets and antiparallel /beta sheets.
What does the primary structure of a protein refer to?
The amino acid sequence of the protein
What is the name for a modular unit from which many larger proteins are made?
Protein domain
.In a protein, intrinsically disordered sequences:
A. have a variety of important functions.
B. can wrap and bend around target proteins.
C. are ideal substrates for the addition of chemical groups that can modify protein behavior.
Theoretically, a vast number of different proteins can be assembled from 20 different amino acids. How many polypeptide chains are possible that are 10 amino acids long?
20^10
What are protein families?
Evolutionarily related proteins that are similar in amino acid sequence and three-dimensional conformation.
What is the definition of a binding site on a protein?
Any region that interacts with another molecule through sets of noncovalent bonds.