Structures of glycine and alanine are given below. Show the peptide linkage in glycylalanine.
Glycine and alanine on reaction with each other produces glycylalanine as
Protein found in a biological system with a unique three-dimensional structure and biological activity is called a native protein. When a protein in its native form, is subjected to a physical change like change in temperature or a chemical change like, change in pH , denaturation of protein takes place. Explain the cause.
Due to physical and chemical change, hydrogen bonds in proteins are disturbed. Due is this globules unfold and helix gets uncoiled and therefore, protein loses its biological activity. This is known as denaturation of proteins.
Activation energy for the acid catalysed hydrolysis of sucrose is 6.22 kJ $\mathrm{mol}^{-1}$, while the activation energy is only $2.15 \mathrm{~kJ} \mathrm{~mol}^{-1}$ when hydrolysis is catalysed by the enzyme sucrase. Explain.
Enzymes, the biocatalysts reduce the magnitude of activation energy by providing alternative path. In the hydrolysis of sucrose, the enzyme sucrase reduces the activation energy from $6.22 \mathrm{~kJ} \mathrm{~mol}^{-1}$ to $2.15 \mathrm{~kJ} \mathrm{~mol}^{-1}$.
How do you explain the presence of an aldehydic group in a glucose molecule?
Glucose on reaction with bromine water produces gluconic acid. This indicates the presence of CHO group.
Which moieties of nucleosides are involved in the formation of phosphodiester linkages present in dinucleotides? What does the word diester in the name of linkage indicate? Which acid is involved in the formation of this linkage?
(i) $5^{\prime}$ and $3^{\prime}$ carbon atoms of pentose sugar.
(ii) Most probably the resemblance of with 2 ester $(-\mathrm{COO})^{2-}$ groups joined together.
(iii) Phosphoric acid $\left(\mathrm{H}_3 \mathrm{PO}_4\right)$.
Nucleosides are joined together by phosphodiester linkage between $5^{\prime}$ and $3^{\prime}$ carbon atoms of pentose sugar and a dinucleotide with phosphoric acid $\left(\mathrm{CH}_3 \mathrm{PO}_4\right)$ is formed
