Zhihong Li, PhD Department of Biochemistry Introduction to Biochemistry （生物化学）

Biochemistry Definition: The chemistry of life –concerned with the chemical basis of life. –concerned with the various molecules that occur in living cells and organisms and with their chemical reaction. Aim: to describe and explain, in molecular terms, all chemical processes of living cells –Structure-function –Metabolism and Regulation –How life began ？

Biochemistry Significance: be essential to all life sciences as the common knowledge –Genetics; Cell biology; Molecular biology –Physiology and Immunology –Pharmacology and Pharmacy –Toxicology; Pathology; Microbiology –Zoology and Botany

Cells Basic building blocks of life. Smallest living unit of an organism. A cell may be an entire organism (unicellular organism) or it may be one of billions of cells that make up the organism (multicellular organism). Grow, reproduce, use energy, adapt and respond to their environment.

Cells May be Prokaryotic or Eukaryotic Prokaryotes (Greek: pro-before; karyon-nucleus) –include various bacteria –lack a nucleus or membrane-bound structures called organelles Eukaryotes (Greek: eu-true; karyon-nucleus) –include most other cells (plants, fungi, & animals) –have a nucleus and membrane- bound organelles

Characteristic Bio-membranes and Organelles Mitochondria- the power generators Mitochondria (Greek: mitos-thread; chondros-granule): Surrounded by a double membrane with a series of folds called cristae. Functions in energy production through metabolism. Plasma Membrane-Cell’s defining boundary Providing a barrier and containing transport and signaling systems. Nucleus – Cell’s information center Double membrane surrounding the chromosomes and the nucleolus. The place where almost all DNA replication and RNA synthesis occur.

Rough endoplasmic reticulum (RER) Covered with ribosomes (causing the "rough" appearance) which are in the process of synthesizing proteins for secretion or localization in membranes. Ribosomes: responsible for protein synthesis Smooth endoplasmic reticulum (SER) A site for synthesis and metabolism of lipids. Endoplasmic reticulum (ER) – The transport network for molecules

Cytoplasm enclosed by the plasma membrane, liquid portion called cytosol and it houses the membranous organelles. Lysosomes-contain digestive enzyme A membrane bound organelle that is responsible for degrading proteins and membranes in the cell. Golgi apparatus -process and package the macromolecules. A series of stacked membranes. Vesicles move between the stacks while the proteins are "processed" to a mature form.

Biomolecules Building blocks of cells. Animal and plant cells contain approximately 10,000 kinds of biomolecules. –Water: constitutes 50-95% of cells contents by weight. –Ions: like Na +, K + and Ca 2+ may account for another 1%. –Organic compounds: compounds composed primarily of a Carbon skeleton.

Types of biomolecules Small molecules: –Lipid, phospholipid, glycolipid, sterol –Vitamin –Hormone, neurotransmitter –Carbohydrate, sugar Monomers: –Amino acids –Nucleotides –Monosaccharides Polymers: –Peptides, oligopeptides, polypeptides, proteins –Nucleic acids, i.e. DNA, RNA –Oligosaccharides, polysaccharides (including cellulose)

Chemical composition of a normal man (weight 65 kg) ConstituentPercent (%)Weight (kg) Water Protein Lipid13.89 Carbohydrate1.51 Minerals6.14

Structural hierarchy in the molecular organization of cells

TopicsInstructor 1Introduction, amino acid and protein (6h)Zhihong Li 2Nucleic acid (4h)Zhihong Li 3Carbohydrates (2h)Zhihong Li 4Vitamins (4h)Zhihong Li 5Enzymes (6h)Zhihong Li 6Metabolism of carbohydrates (8h)Yanlin Wang 7Midterm assessment 8Bioenergetics (4h)Zicheng Li 9Metabolism of lipids (6h)Deqiao Sheng 10Metabolism of amino acids (6h)Zicheng Li 11Integration of metabolism and review(2h)Zicheng Li

Satyanarayana U, Biochemistry. Murray RK, Harper’s Illustrated Biochemistry, 26th ed. Nelson DL and Cox MM. Lehninger Principles of Biochemistry, 5 th ed. Text book and references

Inspiring interest, confidence Previewing and reviewing freshly Taking studying notes Discussing in groups Practice, crosstalk with other subjects Making use of internet Some tips for study of Biochemistry

Final theory grade Final theory grade= –Daily performance: 15% –Midterm assessment: 30% –Final exam: 55% Notice: 1/3 absent, can not take part in the final exam.