CBSE Class 12 Chemistry Biomolecules Notes and Questions

CBSE Class 12 Chemistry Biomolecules Notes and Questions. Based on CBSE and NCERT guidelines. The students should practice these Questions to gain perfection which will help him to get more marks in CBSE examination. Based on CBSE and NCERT guidelines. The preparation should be in a manner which helps the students to concentrate more in areas which carry more marks. 

Bio molecule

Gist Of The Chapter

1.Carbohydrates- These are optically active polyhydroxy  aldehydes or ketones due to presence of chiral `C’ or the compounds which produce these on hydrolysis except dihydroxy acetone is not optically active.

2. Classification-

(i) Monosaccharide’s – Those carbohydrates which cannot get hydrolysed e.g. glucose ,fructose, galactose etc.

(ii) Oligosaccharides- Those carbohydrates which give to or more monosaccharide’s on hydrolysis e.g. sucrose on hydrolysis gives glucose and fructose. Raffinose on hydrolysis gives glucose, fructose and galactose.

(iii) Polysaccharides- Those carbohydrates which on hydrolysis give large number of monosaccharide’s hydrolysis.eg  starch, cellulose, glycogen.

3. Sugar-

(i) Reducing Sugars- Those which reduce Fehling’s or Tollen’s reagent. They have free aldehydic groups, eg , glucose, fructose , galactose

(ii) Non Reducing Sugars- Those which do not reduce Fehling’s or Tollen’s reagent. They do not have free functional group ,e.g.,  sucrose

4. Glucose- It is a monosaccharide’s with molecular formula C₆H₁₂O₆

5. Preparation

(i) From Sucrose

     C₁₂H₂₂O₁₁ + H₂O ------->  C₆H₁₂O₆ + C₆H₁₂O₆ ( Only from sucrose)                                        

(ii)From Starch

(C₆H₁₀O₅)_n + nH₂O -------> C₁₂H₂₂0₁₁ + H₂0 ------> 2C₆H₁₂O₆