Dr. Md.
Mashiur Rahman
Senior Lecturer
Dept. of Biochemistry
EBAUB
BIOCHEMISTRY
Definition: Biochemistry is the branch of science concerned with studying the
various molecules, chemical reactions and processes that occur in
the living organisms.
Carl Neuberg first introduced the term Biochemistry in 1903.
Objectives: Complete understanding of all the chemical processes associated
with living organisms at the molecular level.
Branch of Biochemistry: Biochemistry can be divided broadly into four branches.
These are-
1. Medical Biochemistry
2. Animal Biochemistry
3. Plant Biochemistry
4. Biochemistry of microorganism
Importance/Scope: Biochemistry is the chemistry of living organism. The scope of
Biochemistry is as vast as life itself. Biochemistry has wide spread use to advances the
knowledge in different areas including health, agriculture and the environment.
In medicine: Biochemistry is a valuable subject in medicine. It helps to understand
the actual pathophysiological condition and their treatment.
In clinical Biochemistry: Almost all the diseases and disorder have some
biochemical alteration and different biochemical tests are being used to diagnosis the
clinical conditions.
In agriculture: Biochemistry plays important role in farming, fishery, poultry,
sericulture, bee keeping etc.
In pharmaceuticals: Biochemistry provides an idea of drug composition, half-life,
metabolism and their storage.
In plant: Biochemistry describes the photosynthesis, respiration, metabolism, and
different functions of plants.
Biomolecules
Biomolecules: A biomolecule can be defined as any organic molecule produced by living
organisms. They consist mostly of carbon, hydrogen, nitrogen, and oxygen, and have a small
amount of sulfur and phosphorus. e.g. Proteins, carbohydrates, lipids, hormones, nucleic
acids, vitamins etc.
Type of biomolecules: A diverse range of biomolecules exist, including small molecules
and macromolecules. Macromolecules are comprised of small molecule. Some examples are
as follows-
Small molecule Macromolecule Atomic constituents
Amino acid Poly peptides, Proteins C, H, O, N (S)
Sugars Starch, Glycogen C, H, O
Fatty acids Fats, Oils C, H, O
Purines and Pyrimidine Nucleic acids C, H, O, N
Nucleotide Nucleic acids (DNA and RNA) C, H, O, N, P
Characteristics of Biomolecules:
1. Biomolecules are organic compounds.
2. They have specific shapes and dimensions.
3. Functional group determines their chemical properties.
4. Many of them are asymmetric.
5. Macromolecules are large molecules and are constructed from small building block molecules.
6. Building block molecules have simple structure.
Importance of Biomolecules:
1. Carbohydrates: It is very important source of energy for any physical function.
2. Proteins: Proteins are the fundamental basis of structure and function of the cell.
3. Lipids: Lipids are the storage form of energy to meet the long term demand; structural components of
membranes.
4. Nucleic Acids (DNA, RNA): Nucleic acids are very important as DNA carries the hereditary
information and RNA helps in protein formation for the body.
5. Enzymes: Enzymes are simple or combined proteins acting as specific catalysts and activates the
various biochemical and metabolic processes within the body.
