Chemical building blocks of cells C-3-3

Organic compounds = compound that contains Carbon Macromolecules = built from small organic compouns

4 kinds of Macromolecules: 1.) Carbohydrates: * composed of C, H, O in a 1:2:1 ratio Ex… glucose is C6H12O6 ~ stores and transports energy in the body Ex… Polysaccharides = linked sugars in a long chain

2.) Lipids: * special b/c they don't dissolve in water Ex… oils, waxes, fats Functions: ~energy storage ~ structural support in cell membrane ~ specific reactants for metabolic rxns

Fats = energy storage * fats supply more energy than carbs 1g fat = 9 cal 1g carbs = 4 cal Saturated fats -- contain single C-H bonds Unsaturated fats – has at least double bond C=C

3.) Proteins -- long chains of polypeptides -- long chains of amino acids (20 kinds) Enzymes - type of protein that assists in chem rxn of metabolism ~ increase rate of chem rxn w/o being used up = catalyst

4.) Nucleic Acids: ~ long chains of small, repeating sub-units called nucleotides -- 5C sugar w/ a phosphate group (PO4) on one side and organic base on the other --functions to store genetic info Ex...DNA & RNA

ATP - adenosine triphosphate - an organic base, a sugar, and 3 (PO4) groups * ATP is the energy currency of the cell

Energy and Chemical Reactions C-3-4

Chemical reaction – chemical bonds between atoms are broken or formed Reactants - substances that bind or are broken apart Products - new substance that is formed Ex: Breakdown of sugar or making a protein

Type of Reactions Exergonic reaction – releases free energy *products contain less energy than the reactants Ex: Cellular respiration Endergonic reaction – absorbs free energy *products contain more energy than the reactants Ex: Photosynthesis

Catalysts Enzymes: *Catalysts that trigger and control specific chemical rxns *type of protein *binds to specific reactant molecules *not used up or changed in the reaction

Enzymes *bind to a specific site – active site *Each have an optimal temperature and pH *alter the chemical reaction to go at a lower activation energy level *not altered during the reaction *do not make reactions happen spontaneously

Metabolism Energy transferring rxns in cells Allows maintenance of homeostasis Driven by ATP