Chapter 3: Amino acid protein structure, purification, & analysis

Question 1

Proteins are what?

Answer 1

Peptides with an amino acid sequence directed by the genetic code

Question 2

How many possibilities are there for the primary structure of amino acids?

Answer 2

20^n possibilities (n= to the # of amino acids)

Question 3

The secondary & tertiary structure of proteins are what?

Answer 3

3D functional shape

Question 4

Quaternary structure is what?

Answer 4

Multiple folded polypeptides in a protein

Question 5

Proteomics

Answer 5

Study of cellular protein complement over time & varying conditions

Question 6

Conjugated proteins

Answer 6

Are proteins that contain more than just amino acid group where coenzymes and prosthetic groups are bound to proteins and required for protein function (ex. lipoproteins where lipids is its prosthetic group)

Question 7

Most studies & assays require protein purity of how much percent?

Answer 7

95-98%

Question 8

What is the common technique used for protein separation

Answer 8

Chromatography

Question 9

What are all the fractioning techniques?

Answer 9

1. Salting out
2. Ion exchange chromatgraphy
3. Gel electrophoresis
4. Isoelectric focusing
5. Hydrophobic ineteraction

Question 10

Proteins are least soluble when?

Answer 10

At the pI

Question 11

Proteins are net positively charged when?

Answer 11

At pH below pI

Question 12

Proteins are net negatively charged when?

Answer 12

Above the pI