BIOCHEMISTRY 生物化学. 2011.08.30. PLEASE TURN OFF OR SILENCE YOUR PHONE. Lecturers: Wang, Fei ( 王菲 ) Ph.D College of Biotechonology Institute of Sericulture & Systems Biology Li, Guanrong ( 李关荣 ) Ph.D College of Agronomy and Biotechnology Office Hours: Tuesday, 4:00-5:30PM
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Textbooks & References
David L. Nelson Michael M. Cox
W.H. Freeman and Company
What is Biochemistry?
Biochemistry describes in molecular terms the structures,mechanisms, and chemical processes shared byall organisms and provides organizing principles thatunderlie life in all its diverse forms, principles we referto collectively as the molecular logic of life.
Because it is all about life!
Biomolecules Are Constructed by a Variety of carbon bonding
Biomolecules Are Compounds of Carbon with a Variety of Functional Groups
Macromolecules Are Polymers of block-building molecules
Proteins: polymers of amino acids
Poly-saccharides: polymers of sugars
Lipids: composed by fatty acids, glycerol, choline,.
Nucleic acids: polymers of nucleotides
Configuration and Conformation
Configuration: the fixed spatial arrangement of atoms
Stereoisomers: molecules with the same chemical bonds but different stereochemistry-different configuration
Geometric isomerism/cis-trans isomerism:/
Chiral center : A carbon atom with four different substituents asymmetric arranged 4
A molecule with only one chiral carbon can have two stereoisomers; when two or more (n) chiral carbons are present, there can be 2nstereoisomers.
Enantiomers (): stereoisomers are mirror images of each other
Diastereomers (): pairs ofstereoisomers that are not mirror images of each other
Conformation: the spatial arrangement of substituent groups that, without breaking any bonds, are free to assume different positions in space because of the freedom of rotation about single bonds
Water forms hydrogen bonds with polar solutes
The forces that hold the nonpolar regions of the molecules together
Molecular Weight, Molecular Mass, and Their Correct Units
Mr: molecular weight (relative molecular mass)
is defined as the ratio of the mass of a molecule of that substance to one-twelfth the mass of carbon-12 (12C)
Molecular mass (m):mass of one molecule, or the mo-
lar mass divided by Avogadros number
1 d= 12C1/12 1.6602x10-27kg