Primary Structure (Exam 1 - Chapter 5)

What is a primary structure?

a specific sequence in a polypeptide

What is a backbone?

the repeating parts of the polypeptide

In a polypeptide which group is the hydrogen - bond donor?

the N-H group (amine group)

n a polypeptide which group is the hydrogen - bond acceptor?

the C=O group (carbonyl group

Which type of configuration is seen in peptide bonds? Why?

Trans configuration is lower in energy and is a stable condition because there is no steric hinderance or electric repulsion.

Is the peptide bonds a double or sing bond?

double bond

Which type of bonds have free rotation?

single bonds

What is the enzyme - linked immunosorbent essay (ELISA) ?

a process that tests the detectence of an antibody

How does enzyme - linked immunosorbent essay (ELISA) work?

Antibodies are placed in a well with antigens. If the antibody that we are looking for (antibody of interest) is present it will bind to the antigen.

A fast and common method for determining the protein concentration in column effluent is

measuring light absorption at 280 nm.

How do we separate a protein of interest from a protein mix?

through a process of protein purification

What type of ions does salting out give insight to?

cation (+) and anion (-)

What is salting out?

based on the solubility of proteins. Directed at the concentration of dissolved salt to eliminate unwanted proteins.

What characteristics affect the solubility of proteins?

polarity, pH, and temperature

What does salting out lead to?

competition between added salt ions

What is ion exachange?

separates anions and cations based on the pH of the protein

Anion exchangers

when the anion binds to the cation

Cation exchange

when the cation binds to the anion

What affect the affinity for binding in ion exchange?

pH

What is an essential component need for ion exchange?

a buffer

What is immunoaffinity chromatography?

uses antibodies to separate proteins

In Immunoaffinity chromatography ligand through the process is also used. What is it for?

ligand is the glue that help strengthen binding the antibodies and antigen

What is SDS Page?

Uses gel electrophoresis to separate the proteins by size. (Protein are denatured)

How would small and larger protein be distinguished in a gel electrophoresis?

the smaller proteins would migrate faster and will have a lower kda value. The larger proteins would migrate slower which will cause it to have a larger kda value.

What are the reducing reagents for disulfide cleavage?

beta - mercaptoethanol and Dithiothreitol

What is endopeptidase?

an enzyme that breaks internal peptide bonds

What is the reagent used for endopeptidase?

trypsin

What is exopeptidase?

an enzyme that cuts out the peptide form the N and C terminal

What promotes peptide cleavage?

cyanogen bromide

What

What are the two endopeptidase specificity enzymes in the Bovine Pancreas?

trypsin and chymotrypsin