Biochemistry The chemicals of LIFE

Essential Elements: CHON Carbon, Hydrogen, Oxygen, and Nitrogen make up 98% of all living material. C HOPKINS CaFe Mg NaCl Make up 99% of all living substances

Types of Chemical Bonds Ionic Bonds: weak bonds formed when metals transfer electrons to nonmetals. How are ionic bonds held together? Covalent Bonds: a stronger bond that is formed when two non-metals share electrons. Their valence shells overlap. Hydrogen Bonds: a weak ionic bond formed between hydrogen and fluorine, oxygen, and nitrogen.

Polar vs. Ionized: Molecules can have ends that contain charges without gaining or losing electrons Polar molecules exist because atoms share electrons unevenly based on electronegativity Ionic compounds will gain or lose electrons leaving different parts of their molecules with different charges.

Water: the cradle of life Polar molecule A universal solvent: it will dissolve all other polar molecules through Hydrogen bonding High Specific Heat Capacity

Organic Molecules: Carbon containing molecules: How many bonds can carbon form? What shapes of molecules can carbon form? What is a functional group? Hydroxyl? Carboxyl? What is an isomer? Monomer vs. Polymer?

Water cont’d Water Ionizes: breaks down into H+ and OH- Hydrophobic/Hydrophilic: Phobic: water fearing (non-polar) Philic: water loving (polar) Cohesion/Adhesion: Co: water sticking to water Ad: water sticking to other polar molecules

Macromolecules: Definition: huge molecules consisting of thousands of smaller molecules. Proteins: thousands of amino acids Carbohydrates: thousands of monsaccharides Lipids: 3 fatty acids + glycerol Nucleic Acids: nucleotides Polymer: chain of repeating units. Built through a dehydration synthesis reaction that removes a water to add a bonding site. Broken down through hydrolysis reactions by adding water.

Carbohydrates: Always contain H,C,O H:O Ratio is 2:1 Uses: C6H12O6 C12H22O11 C18H32O16 Uses: Energy: main energy source within the cell Building blocks for all amino acids, fatty acids, and nucleic acids

Examples of Carbohydrates: Monosaccharides: immediate energy Glucose Galactose Fructose Disaccharides : Sucrose lactose Polysaccharides: large storage molecules Glycogen Amylose Cellulose Chitin

Lipids: Always contain C, H, O but much less O than carbohydrates Fatty acid/glycerol polymer 84 fatty acids in humans Found in fat, wax, and oil Insoluble in water Non-polar Storage molecules

Lipids Cont’d Above: saturated and unsaturated fat molecules Right: the structure of a normal unsaturated fat and a trans unsaturated fats

Lipids Cont’d: Phospholipids: make up the bi-layer of a cell membrane. Consist of polar heads and non-polar tails.

Cholesterol: acts as a cement to hold the lipid bi-layer together Steroids: hormones Cholesterol: acts as a cement to hold the lipid bi-layer together http://telstar.ote.cmu.edu/biology/MembranePage/ind ex2.html

Proteins: Always contain C, H, O, N An amino acid polymer

Interactions between amino acids and hydrogen bonds give proteins their shape Uses: Catalysts Transport Coordinated movements Structural support Immune

Nucleic Acids: Nucleotide polymer DNA: deoxyribose sugar Nitrogen bases ATCG Determine genetic traits RNA: ribose sugar with bases AUCG Carry important genetic information