Introduction to molecular biology of the cell

Haixu TangSchool of Informatics

All living things are made of cells

The Universal Features of Cells on Earth

➢ Store Their Hereditary Information in the Same Linear Chemical Code (DNA)

➢ Replicate Their Hereditary Information by Templated Polymerization➢ Transcribe Portions of Their Hereditary Information into the Same

Intermediary Form (RNA)➢ Use Proteins as Catalysts➢ Translate RNA into Protein in the Same Way

One Protein Is One GeneA Living Cell Can Exist with Fewer Than 500 Genes

➢ Life Requires Free Energy➢ All Cells Function as Biochemical Factories Dealing with the Same Basic

Molecular Building Blocks➢ All Cells Are Enclosed in a Plasma Membrane Across Which Nutrients and

Waste Materials Must Pass

Hereditary Information is stored in the Same Linear Chemical Code (DNA)

Templated Polymerization

Proteins as Catalysts

One gene, one protein

Mycoplasma genitalium: 477 genes

Hereditary Information into the Same Intermediary Form (RNA)

Translate RNA into Protein

Cells Can Be Powered by a Variety of Free Energy Sources

➢ Organotrophic: feeding on other living things or the organic chemicals they produce

➢ Phototrophic: harvest the energy of sunlight

➢ lithotrophic: capture their energy from energy-rich systems of inorganic chemicals in the environment

Formation of a membrane by amphipathic phospholipid molecules

Diversity of living cells