Table of Contents

Types of Biomolecules:

  1. Carbohydrates
  2. Lipids
  3. Vitamins
  4. Minerals
  5. Nucleic acids

1 Carbohydrates

  • also known as sachharides
  • basic component: sugars
  • Cn H2n On - C6 H12 O6 (glucose)
Small Carbohydrates Large Carbohydrates
soluble in water insoluble in water
low molecular weight high molecular weight
sweet taste taste not sweet
called monosacchrides called polysacchrides

1.1 Monosachhrides

  1. Deoxyribose (present in DNA)
  2. Ribose (present in RNA)
  3. Glucose, aka blood sugar, corn sugar, grape sugar – common respiratory substrate.
  4. Frucose (fruit sugar) – sweetest of all naturally ocurring sugars.

1.2 Disacchrides

  1. Maltose: glucose + glucose = malt sugar (barley sugar)
  2. Lactose: glucose + galactose = milk sugar
    • example of reducing sugar
    • reduces Cu2+ to Cu+ in Benedict/Fehling solution

1.3 Polysacchrides

  1. Starch: storage polysachhride of most plants
  2. Glycogen: animal startch (storage), stored in liver and muscles
  3. Cellulose: structural polysachhride

1.3.1 Cellulose

It provides structure to plant cells and is the most abundant organic substance in biosphere. It is a structural polysachharide present in the cell wall of plants. There are several important applications of cellulose and its derivatives:

  1. Cellulose nitrate: used in explosives
  2. Carboxy methyl cellulose (CMC) is used as an emulsifying agent in ice creams, medicine, cosmetics, etc.
  3. Cellulose accetate: in fabricating fibres, plastics, shatterproof glasses, etc.

1.3.2 Chitin

It is another structural polysachharide that is found in the cell walls of fungi and in exoskeleton of insects. It is the second-most abundant organic compound.

1.3.3 Agar-agar

It is obtained from algae and is used as a medium to grow cultures of bacteria.

2 Lipids

Lipids, or fats are a fatty acid esters of alcohol (glycerol) and related substances which are insoluble in water but get dissolved in a number of non-polar organic solvents like ether, benzene, chloroform, etc. (An ester is a compination of acid and alcohol).

Basic unit of all lipids: fatty acids.

2.1 Saturated & Unsaturated Fats

Saturated Fats Unsaturated Fats
Single bonds between C-C (i.e. Carbon is saturated with H-atoms) Double bonds between C=C
Solid state, e.g. animal fats like ghee. Liquid state, e.g. vegetale oils
Higher melting point Lower melting point
increase blood cholesterol doesn't increase blood cholesterol as much as saturated fats

2.2 Hydrogenation

It is the process of conversion from unsaturated fats to saturated fats. Metals like nickel and manganese are used in this process.

2.3 Essential Fatty Acids

These fatty acids are needed by animals but their bodies don't have the ability to synthesize them and are required in the diet. The deficiency leads to skin-related disorders. They are:

  1. Linoleic acid
  2. Linolic acid
  3. Arachidonic acid

3 Proteins

They are made of amino acids. All amino acids contain amino group and carboxylic group.


20 types of amino acids present in proteins are required by humans. e.g. glycine (the simplest amino acid) which is required for formation of heme (haemoglobin).

Excess amino acids are de-aminated in liver (urea cycle).

Organic amino acids are changed to glucose via gluconeogenesis.

3.1 Essential amino acids

Plants can synthesize all proteins and amino acids they require. Animals cannot synthesize 7 of the amino acids which are called Essential Amino Acids which must be consumed in diet for normal functioning of the body.

3.2 Enzymes & Antibodies

Enzymes and antibodies are formed of proteins.

An antigen is a foreign particle. To destroy the antigen, the body makes antibodies (immunoglobin).

Enzymes are protenacious substances which are capable of catalyzing chemical reactions of biological origin without themselves undergoing any change. Almost all enzymes are proteins.

Restriction endonuclease is an enzyme used for cutting DNA at specific site. Ligase is an enzyme joining the DNA segments.

ELISA (Enzyme Link Immuno-Sorbent Assay) is the test used to diagnose AIDS.

Detergents contain protease for brighter washing of clothes.

  • Soap acts after mycin formation in the process called saponification.
  • Dishwasher contains amylase, which is also used in digestion.
  • Baby foods contain trypsin which is added to predigest babyfood.

3.3 Examples of proteins

Diet / Function Protein / Enzyme
Milk casein
Egg (white) albumin
Iron-storage in animal tissue ferritin
Muscle contraction actin, myosin
oxygen carrier protein heme
blood clotting fibrinogen, thrombin
dishwasher, digestion amylase
baby food trypsin
soap mycin
Biotechnology ligase, restriction endonuclease
dissolve blood clots in vessels streptokinase
anti-coagulant heparin
fermentation, brewing, baking zymase
cheese production rennet/rennenin
green coffee pectinase

Sidenote: In the process of blood clotting, the proteins involved are fibrinogen and thrombin, the mineral involved is calcium and the vitamin involved is Vitamin K.

Protein deficiency leads to PEM diseases (Protein Energy Malnutrition diseases) like kwashiorkor and marasmus.

4 Vitamins

They are the essential food factors which are required in small quantities for optimum functioning of metabolic pathways and body functions.

First vitamin to be discovered Thiamine (B1)
Vitamin which can be made by intestinal bacteria Vitamin A
Vitamin created from cholesterol derivatives in the presence of sunlight Vitamine D

4.1 Classification

  1. Fat soluble: A, D, E, K
  2. Water soluble: B, C

Author: likeaflower

Created: 2018-05-07 Mon 01:36

Emacs 24.5.1 (Org mode 8.2.10)