Tag: evs - i

• Histones are a family of basic proteins that associate with DNA in the nucleus and help condense it into chromatin, they are alkaline (basic pH) proteins, and their positive charges allow them to associate with DNA.
  
• Five types of histones have been identified: H1 (or H5), H2A, H2B, H3 and H4.
• The core histones are H2A, H2B, H3, and H4, and the linker histones are H1 and H5. These types of histones are smaller, each consisting of 100-150 residues.
  
• H1 and its homologous protein H5 are involved in higher-order structures of chromatin consisting about 220 residues.
  
• The ratio of H1 and H3 proteins in chromatin is 1:2

Amylase is a protein enzyme, a polymer of amino acids. Glycogen is homopolysaccharide of D-glucose with highly branched structure (every 8-12 residues as compared to presence of branches in starch for every 24-30 residues). Phopholipids have phosphate and lipids (carbon and hydrogen atoms) while polysaccharides are polymer of simple sugars. RNA is polymer of ribonucleotides. 

Proteins are the building blocks, which takes part in several metabolic reaction. They have four different levels of structure primary, secondary, tertiary and quaternary. There are 20 different standard L-α-amino acids used by cells for protein construction. Amino acids contain both a basic amino group and an acidic carboxyl group. This difunctionality allows the individual amino acids to join together in long chains by forming peptide bonds: amide bonds between the -NH2 of one amino acid and the -COOH of another. Sequences with fewer than 50 amino acids are generally referred to as peptides, while the terms protein or polypeptide are used for longer sequences. A protein can be made up of one or more polypeptide molecules. The end of the peptide or protein sequence with a free carboxyl group is called the carboxy-terminus or C-terminus. The terms amino-terminus or N-terminus describe the end of the sequence with a free α-amino group. The amino acids differ in structure by the substituent on their side chains. These side chains confer different chemical, physical and structural properties to the final peptide or protein.
So, the correct answer is option B.

Amino acids are the building blocks of polypeptide chain or proteins. These are encoded by the triplet codons of mRNA. Each codon synthesizes a specific amino acid. Example: AUG for methionine, UUU for phenylalanine and so on. Amino acids are connected via the peptide bonds to form the proteins.

Proteins are the polymers of amino acids linked with peptide bonds and perform various functions like carrier, enzyme or hormone. It is considered the most diverse molecule and differs from animal to animal. The diversity in proteins occurs due to the R group present which changes with the change in the amino acid.

a) Glycerol has chemical formula of  C$ _3$H$ _8$O$ _3$. 3 OH groups act as binding site. The carboxyl end of the fatty acid combines with the three -OH groups of the glycerol to form ester. The statement is true.

Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Amino acids are Linked by peptide bonds to form polypeptide chains. Proteins are linear polymers formed by linking the α-carboxyl group of one amino acid to the α-amino group of another amino acid with a peptide bond (also called an amide bond).

An amino acid is the structural and functional unit of protein and are made up of carbon, hydrogen, oxygen, nitrogen and sometimes sulphur. These are organic acids with a carboxyl group and one amino group.  Amino acid acts as a buffer. 

There is no gravity in space, so the objects keep floating in space due to lack of gravitational force. Sunita Williams wanted to show that objects kept floating in space. She shared some experiences that they kept floating in spaceship, water floats around as blobs, her hair kept standing all the time in spaceship etc.