RBSE Class 12 Chemistry Notes Chapter 14 Biomolecules

These comprehensive RBSE Class 12 Chemistry Notes Chapter 14 Biomolecules will give a brief overview of all the concepts.

RBSE Class 12 Chemistry Chapter 14 Notes Biomolecules

→ Biochemistry: The branch of science that deals with the study of the chemical composition and structure of living organisms and molecules in them and also various changes taking place within them.

→ Carbohydrates: Carbohydrates are defined as the polyhydroxy aldehydes and polyhydroxy ketones or the other compounds which give these on hydrolysis. 

→ Mono saccharides : The simple carbohydrates that cannot be broken further into lower sugars on hydroly-sis e.g. glucose, fructose, ribose etc.

→ Oligo saccharides: These are the carbohydrates which on hydrolysis give two to ten units of monosaccharides on hydrolysi e.g. sucrose, maltose etc.

→ Polysaccharides: There are the carbohydrates which produce a large number of monosaccharides units on hydrolysis e.g. Starch, cellulose etc.

→ Reducing sugar: Those carbohydrates which contain free aldehydic or ketonic group and reduce Fehling's solution and Tollen's reagent are called reducing sugar, e.g. all monosaccharides, maltose and lactose.

→ Non-reducing sugars: The carbohydrates do not reduce Fehling's solution and Tollen's reagent are called non-reducing sugar, e.g. sucrose.

→ Aldose: If monosaccharides contains aldehyde group called aldose.

→ Ketose: If monosaccharides contains ketone group are called ketose.

→ Fehling's Solution: It is dark blue solution. Fehling A is aqueous CuSO₄ solution and Fehling B is aquarius NaOH solution in which Roschell's salt added in same volume.

→ Tollen's Reagent: It is ammonical silver nitrate solution.

→ Anomer: Both cyclic hemicacetal C is different in con-figuration of hydroxyl group. That is called anomeric carbon. Its isomers is called, kind.

→ Mutarotation: Both types of anomers (and) dissolve in water and change the specific polar rotation. This type of rotation is called mutarotation.

→ Glycosidic linkage: When two monosaccharides are added remove one molecule of water formed disaccharides that type of bond is called oxide bond and glyco-sidic linkage.

→ Invert sugar: Sucrose is southpolar but after hydrolysis it gives south. However Glucose and north polar fructose pertaps right polar rotation value (- 92.4) is more than south polar rotation (+ 52.5). So hydrolysis of sucrose changes sign from south (+) to north (-). And the product is called Invert sugar.

→ Polypeptide: Polymers of -amino acids which have high molecular masses up to 10,000 is called polypetides.

→ Amino-acids : Amino acids contains amino (- NH₂) and carboxylic (- COOH) functional groups.

→ Neutral amino acids : If the no. of amino group and carboxylic group are same in amino acids are called neutral amino acids. Example: alanine.

→ Basic Amino acids : It amino groups are more than carboxylic groups in amino acids are called basic amino acids.

→ Acidic Amino acids: If carboxylic groups are more than amino group in amino acids are called Acidic amino acids.

→ Essential Amino acids : Amino acids which are not synthesised in human body so it is essential to take in diet are called essential amino acids, e.g. Tryptophan.

→ Non-essential amino acids: That amino acids which are synthesised in human body are called non-essential amino acids, e.g. Glutamine.

→ Zwitter ion or amphoteric ion: Carboxylic group of aqueous solution of amino acids remove one proton but amino group accept one proton thats why it formed dipolar ion. It is called zwitter ion.

→ Iso electric point: Amino acids behaves like zwitter ion on which pH value is called iso electric point.

→ Peptide linkage: Proteins are polymer of -amino acids which bonded by peptide bonds each others. It forms between - NH group and -COOH group. It is (—CO— NH—).

→ Fibrous proteins : When chains of poly peptides are paralled and joined by hydrogen and disulphide bond thenfibre like structure is formed.

→ Globular Proteins: When poly peptides are joined and form circular structure then globular proteins are formed.

→ Vitamins : Organic substances which are important for growth and biological activities of animals and humans are called vitamins.

→ Some Important Points

• Poly hydroxy aldehyde and ketone or that substance which give polyhydroxy aldehyde or ketone on the hydrolysis are called carbohydrates.
• Proteins which acts as catalyst in biochemical reaction are called enzymes.
• That organic natural substances which are prepared by use of same or different -amino acids are called protein
• Change in value of rotation is solution of substance with time is called mutarotation.
• Disaccharides are classified into reducing and non-reducing sugars.
• Sucrose is dissacharide, non reducing sugar which is also called desired sugar.
• Maltose and lactose are disaccharide reducing sugar.
• Maltose is called "Malt sugar" and Lactose is called "Milk sugar".
• Starch and cellulose are poly saccharides sugar.
• Proteins are polymer of complex amino acids with high molecular masses.
• All proteines are formed by different composition of 20 amino acids.
• Amino acids contains Amino (- NH₂) and carboxylic (- COOH) group.
• Polypebtide and proteins are formed by condensation of -amino acids. 
• Changes in structure of proteins due to physical change is called denaturation of proteins.
• Proteins which acts as catalyst in biochemical reactions are called enzymes.
• Hormones are called “gland juice", which control and regulate the biochemical reaction in human body.
• Vitamins are complex organic substance. Small quantity of vitamins are necessary in metabolic process and growth of human and animals.
• Combined form of DNA and RNA is called nucleic acid.