Cell Chemistry and Biosynthesis
Overview Major Atoms Covalent bonds, Ionic bonds Water, non-covalent force in water Four major families of small molecules Sugar, fatty acids, amino acids, nucleotides Three macromolecule families: polysaccharide, protein, nucleic acid Non covalent bonds determine molecular shape and interactions
The Chemical Components of A Cell Basic Element: Atom, protons, Neutrons, Electrons Atomic Weight, Molecular Weight Avgadro’s number (6x10 23 molecules), Mole (1 mole= 6x10 23 molecules), Molar solution (1M=1mole/liter) Electron shells (2,8,8,18,18)
Carbon and Hydrogen
Chemical Elements for Live Organisms H, C, O, and N make up 96.5% weight of a living organism
The Chemical Bonds Ionic Bonds, Covalent Bonds Bond length and bond strength Covalent bonds: Single bond, double bond, polar bond Van der waals force
Covalent Bond and Ionic Bond Ionic bond: electron transfer Covalent bond: electron sharing
Sodium Chloride: ionic bond formation
The geometry of covalent bonds
Important Energy Levels
The Van der Waals forces
The Water Environment 70% of cell is water Hydrogen bond Hydrophilic and hydrophobic Acid and base Proton and hydroxyl Non-covalent interactions in water: Ionic bonds, hydrogen bonds, van der waals attractions, hydrophobic force
Acid Donate a proton Base Absorb a proton or donate OH - NH3+H2O->NH4 + +OH - NaOH->Na + +OH -
Ionic bonds in Water
Hydrogen bond Polar interaction: a elecgtropositive hydrogen is shared by two neighboring electornegative atoms
Molecular Interaction in solution 1. H-bond (hydrogen bond), 2. Ionic bond, 3. Van der Waals 4. Hydrophobic “force”
Four Major Families of Small Organic Molecules Sugars-> polysaccharides Fatty acids -> fats, lipids, membranes Amino acids -> proteins Nucleotides -> nucleic acids
Four Major Small Organic Molecules
Sugar [(CH2O)n, carbohydrates] Glucose
Disaccharide Condensation and hydrolysis
Fatty Acids
Phospholipid (amphipathic)
Amino Acid
Amino Acid and pH values
Peptides and proteins
ATP (ribonucleotide adenosine triphosphate) Nucleotides
Nucleotides and DNA, RNA DNA: deoxyribonucleic acids A(adenine) G(guanine) T(thymine) C (cytosine) RNA: ribonucleic acids A G U(Uracil) C
Macromolecules
Three families of macromolecules
The assembly of macromolecules