About Us who don't know....

Hello everyone. This blog is about us who don't know. Why we created this blog? we don't know...
This blog consist of  3 members who don't know. The leader of don't know is Abdul Rahman. He always say " I don't know" every time lecturer or us ask him anything. I don't know why he don't know. Next author is Shazwan Fahmi who is forced to join this group. The last author who was force to join this group is Krishoreraam.For ur information our leader is imported from Yemen and the youngest among us.

We are the students of MSU. Not Michigan State University, but Management and Science University, Shah Alam. We doing the bachelor in Pharmacy course. This is our second semester and also our first year. That's all about us. hahaha

Picture of Us: Shazwan, Krisho, Abdul Rahman( our leader from Yemen)
p/s: U all can still see the unwillingness from our face...hahaha

What is a Protein? Learn about the 3D shape and function of macromolecules

 Proteins are an important class of molecules found in all living cells. A protein is composed of one or more long chains of amino acids, the sequence of which corresponds to the DNA sequence of the gene that encodes it. Proteins play a variety of roles in the cell, including structural (cytoskeleton), mechanical (muscle), biochemical (enzymes), and cell signalling (hormones). Proteins are also an essential part of diet.

There are 4 levels of structure in proteins

  
       Primary, Secondary, Tertiary, Quaternary

Primary Structure

The linear sequence of amino acids joined together by peptide bonds is termed the primary structure of the protein

Val-Glu-Leu-Ala-Gly-Lys-Met

Peptide bond

• A protein is a linear sequence of amino acids linked together by peptide bonds
• Peptide bonds have a partial double-bond character (rigid & planar)
• Generally in the trans configuration

Secondary Structure

Refers to the regular folding of regions of the polypeptide chain

Most common type of Secondary Structure: 

(A) α-helix (a spiral) 

(B) β-pleated sheet (folds)

Secondary Structural elements are stabilized by extensive hydrogen bonding

(A) α-helix 

• α-helix is a cylindrical, rod-like helical arrangement of the amino acids in the polypeptide chain which is maintained by hydrogen bonds parallel to the helix axis.In a α-helix there are 3.6 amino acids per turn of the helix covering a distance of 0.54 nm. 

  (B) β-pleated sheet

• Hydrogen bonds form between adjacent sections of polypeptides that are either running in the same direction (parallel β-pleated sheet) or in the opposite direction (anti parallel β-pleated sheet).
• Motifs (Super secondary structures) are produced by packing side chains from adjacent secondary elements close to each other.

    Tertiary Structure

• Refers to the 3-dimesional (spatial) arrangement of all amino acids in the polypeptide chain.
• Biologically active (native) conformation stabilized by disulphide bonds, ionic bonds, hydrogen bonds and hydrophobic interactions.
• Domains are the functional and the three dimensional structural unit of a polypeptide. They are formed from combination of motifs

   Quaternary Structure

·   Proteins consists of more than one polypeptide chain have quaternary structure. The poly peptides are held together by covalent (disulphide bonds) or non covalent interactions (hydrophobic interactions, electrostatic forces, hydrogen bonding)