Biochemistry and the unity of life
-Goal of biochemistry: to know what it means to be alive at the molecular level and to
understand how molecular manipulations affect the life the organism leads.
-Organisms are remarkably uniform at the molecular level.
1.1 living systems require a limited number of atoms and molecules
-O, H, and C make up 98% of atoms in an organism.
-matrix of life-refers to O and H-> H2O
-C-C bonds (stability and bond energy, also can dissolve in H2O and can exist as a gas)
are stronger than Si-Si bonds
1.2 There are four major classes of Biomolecules
-Proteins: most versatile, 20 amino acids, 3D structure, serve as signal molecules and
receptors, are catalysts specifically made of proteins are called: enzymes
-Nucleic acid: function: to store and transfer info. Contain instructions. They are linear
and have 4 nucleotides. Nucleotide is made up of: 5-C sugar, deoxyribose or ribose,
attached to a base and one phophoryl group. DNA: parts list, (ACGT), mostly double
stranded, liked by phosphodiester bonds. RNA: (ACGU), single stranded, broken down
after use, used to make proteins, contains additional OH on the sugar.
-Lipids: storage, fuel , and barrier. Smaller than proteins or nucleic acids. Allow
development of inside and outside, signal molecules.
-Carbohydrates: fuel source, starch in plants, recognition of cells (role)
1.3 The central dogma describes the basic principles of biological information transfer
-DNA=genomes, DNA polymerase help to replicate it
-Transcription : DNA RNA