Define the following terms :
(a) Native protein
(b) Nucleotide
(c) Essential amino acid
(a) Native protein
(b) Nucleotide
(c) Essential amino acid
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Solution and Explanation
A protein found in a biological system with a unique three-dimensional structure and a definite biological activity is called a native protein.
Its shape is held by hydrogen bonds, disulphide bridges and other weak forces. If these are disturbed, the protein is denatured and loses its activity.
Step 2: (b) Nucleotide:
A nucleotide is the building block of a nucleic acid. It is made of three parts: a pentose sugar (ribose or 2-deoxyribose), a nitrogenous base and a phosphate group.
It is formed when a nucleoside (sugar plus base) is joined to phosphoric acid, usually at the C5 position of the sugar through an ester link.
Step 3: (c) Essential amino acid:
These are the amino acids which the human body cannot make and which must therefore be taken in the diet.
Examples: valine, leucine, isoleucine, lysine, threonine, methionine, phenylalanine and tryptophan.
Final Answer:
Each term is defined above.
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