Key Concepts - Week 4 - Protein structure and function

Question 1

Key concepts: what structural forms do polypeptides assume?

Answer 1

Polypeptide chain forms mainly three secondary structures such as α-helix, β-sheet, and turn/coil structures through various short-range interactions, which depend on side chain of amino acid residues.

Question 2

Key concepts: how can the sequence of amino acids in a protein be determined?

Answer 2

There are two main methods used to find the amino acid sequences of proteins. Mass spectrometry is the most common method in use today because of its ease of use. Edman degradation using a protein sequenator is the second method, which is most useful if the N-terminus of a protein needs to be characterized.

Question 3

Key concepts: what are the biological roles of proteins?

Answer 3

Proteins are responsible for nearly every task of cellular life, including cell shape and inner organization, product manufacture and waste cleanup, and routine maintenance. Proteins also receive signals from outside the cell and mobilize intracellular response

Question 4

Key concepts: how does chemical bonding determining the formation, stability and the myriad of functions of proteins?

Answer 4

Proteins are the polymers of amino acids. Amino acids are joined together by a special type of covalent bond (peptide bond) to form linear structures called polypeptides. The polypeptides are then folded into specific structures to form the functional conformation of the protein.

Question 5

Key concepts: What makes membrane proteins special?

Answer 5

Membrane proteins mediate processes that are fundamental for the flourishing of biological cells. Membrane-embedded transporters move ions and larger solutes across membranes, receptors mediate communication between the cell and its environment and membrane-embedded enzymes catalyze chemical reactions

Question 6

Point to remember: Proteins are __________ of amino acids linked in series by ________ _______.

Answer 6

POLYMERS

peptide bonds

Question 7

Point to remember: Proteins are the __________ of genetic information

Answer 7

EXPRESSIONS

Question 8

Point to remember: Proteins function to…? (4 points)

Answer 8

1. produce other proteins,
2. control aspects of cellular metabolism,
3. regulate the movement of various molecular species,
4. convert & store energy; and carry out many other activities.