Cell Chemistry and Biosynthesis. Overview Major Atoms Covalent bonds, Ionic bonds Water,...

• 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 (6x1023 molecules), Mole (1 mole= 6x1023 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 BondIonic 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

AcidDonate a proton

BaseAbsorb a proton or donate OH-

NH3+H2O->NH4++OH-

NaOH->Na++OH-

Ionic bonds in Water

Hydrogen bondPolar interaction: a

elecgtropositive hydrogen is shared by two neighboring

electornegative atoms

Molecular Interaction in solution1. 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, RNADNA: deoxyribonucleic acids

A(adenine) G(guanine) T(thymine) C (cytosine)

RNA: ribonucleic acidsA G U(Uracil) C

Macromolecules

Three families of macromolecules

The assembly of macromolecules