Textbook notes Chapter 1
Three parts of Biochemistry:
1. Structural chemistry (components of living matter)
2. Metabolism (totality of chemical reactions in living matter)
3. Genetic Biochemistry (how biological info is stored) leads to molecular genetics
(study of heredity and gene expression)
Biochemistry and the Biological Revolution
- Watson and Crick proposed the structure of the DNA
- Human genome has 2.9 x 10^9 base pairs.
The Roots of Biochemistry
- Biochemistry started in the 1800s
- Wohler demonstrated that he can create urea without a kidney.
- In-vitro: in a test tube
- In-vivo: in living matter
- Biochem is much like molecular biology
- Electron microscopy – cell structure
- X-ray diffraction – 3D structure of macromolecules
- Nuclear Magnetic Resonance – 3D structure of macromolecules Biochemistry as a Discipline and an Interdisciplinary Science
- It is a mix of many other disciplines – organic chem., physical chem.,
Biochemistry as a Chemical Science
- Chemical Elements of Living Matter
o Need C,H,O,N,P,S to be abundant for life
o Early universe was mainly H and He, the burning of which produces
o Life requires large and complex molecular structures, which is why heavier
elements are required – such as C, N, O
o Humans are composed of HOCN
o Inert gases don’t form stable compounds and are not equipped for a role
in life processes
o Human body is 70% water
- Biological Molecules
o DNA has a mass of 2 billion Da
o Proteins are smaller, about 10000-1 million Da
o Macromolecules (giant molecules, make up large portion of mass of a cell)
o Polymers are made of joining monomers through condensation (removal
Carbohydrate is a polymer (ex.cellulose) which is made of
covalently linked monomers, glucose.
Cellulose is a polysaccharide because glucose is a saccharide
Homopolymer – made of the same monomeric unit
Heteropolymer – made from different kinds of monomer units. Nucleic Acids are polymers of nucleotides linked by phosphodiester
Proteins are polymers of amino acids linked by peptide bonds.
o Functions of polymers
Starch stores energy
DNA/RNA stores hereditary info
Proteins can act as hormones, receptors, antibodies, or enzymes.
Lipids have low solubility so they are mainly used for membranes.
Biochemistry as a Biological Science
- Distinguishing Characteristics of Living Matter
o Homeostasis – condition in which the chemical composition of a biological
system is held constant. It is a non-equilibrium steady state.
o Example between equilibrium and homeostasis: at equilibrium the protein