Section 1: Atoms, Elements and Compounds

 Elements pure substances that cannot be broken down chemically  There are 4 main elements that make up 90% of the mass of living things: Carbon – C Oxygen – O Hydrogen – H Nitrogen - N

 Each element has a chemical symbol

 Atoms are the simplest particle of an element.  The properties of atoms determine the properties of the matter they compose  Atomic Structure: Nucleus: the central region of an atom  Made of protons (+) and neutrons (neutral)  The number of protons in an element = the atomic number Electrons: have a negative charge that balances the protons Found in energy levels around the nucleus

Nucleus Energy Level Neutron Proton Electron

 Compounds are pure substances made of two or more elements Shown in chemical formulas  Ex: H 2 O  always 2H for 1O The goal of making compounds is to make atoms stable

 Compounds are held together by bonds Covalent bonds: share electrons Ionic Bonds: electrons are transferred  Results in ions  atoms with a full positive or negative charge

Covalent Bonds Ionic Bonds  Create a Venn Diagram comparing and contrasting Covalent and Ionic Bonds.

 Stand Up  Touch your right elbow to your left knee  Then touch your left elbow to your right knee.  Repeat 9 more times

Section 2: Chemical Reactions

 Chemical Reactions the process through which chemical bonds are broken or made (and sometimes both!) 6H 2 O + 6CO 2 + energy  C 6 H 12 O 6 +6O 2 Reactants: what you put inProducts: what you get out

 Activation Energy energy to start a reaction  Catalysts reduce the amount of activation energy. Enzymes: catalysts found in living things

Visual Concept

Section 3: Water & Solutions

 Solution: a mixture in which one or more substances are uniformly distributed in another substance Solute: the substance dissolved in a solution Solvent: the substance that does the dissolving  Concentration: measurement of the amount of solute in a fixed amount of solution 2% salt = 2g of salt in enough water to make 100mL Saturated Solution: is a solution in which no more solute can dissolve

Section 4: The Building Blocks of Life

 Organic Compounds: made mostly of carbon atoms  Inorganic Compounds: do not contain carbon  Carbon can bond with itself: It can form straight chains It can form branched chains It can form rings

 Monomers: building blocks of organic molecules  Polymer: molecule made of multiple monomers that are linked together  Macromolecules: large polymers Ex: carbohydrates, lipids, proteins and nucleic acids

 Condensation Reaction: monomers are linked to polymers and water is released  Hydrolysis: break down of polymers using water The reverse of a condensation reaction

44 Molecules of Life Carbohydrates (sugars) Proteins (enzymes) Lipids (fats) Nucleic Acids (DNA and RNA)

 Carbohydrates Organic compounds made of carbon, oxygen and hydrogen.  Monosaccharides:  monomer (building block) of a carbohydrate Examples: Glucose & Fructose ○ All 3 monomers have the same formula  C 6 H 12 O 6, but they each have different structures - isomers Glucose Fructose

 Disaccharides: double sugar (two monosaccharides bonded together) The reaction that joins the two monosaccharides together is called a condensation reaction Examples: Sucrose Lactose Sucrose

 Polysaccharides: made of 3 or more monosaccharides bonded together Examples:  Glycogen (in animals): energy storage  Stored in liver and muscle, made of glucose molecules  Starch (in plants): energy storage  Made of glucose molecules  Cellulose (in plants): used for structure  cell wall

 Proteins organic compounds made of carbon, hydrogen, oxygen and nitrogen  Monomer = amino acids 20 different amino acids Functional groups of amino acids:  -COOH, NH 2 What gives the amino acid its specific identity is it’s R-group  R-groups can be simple or complex

 Dipeptides are two amino acids bonded together The bond between amino acids is called a peptide bond Peptide bonds are formed during a condensation reaction

 Polypeptides: very long chains of amino acids  Form larger proteins, which are usually made of more than one polypeptide chain

 Enzymes: Protein (or RNA) molecules that act as biological catalysts  Temperature and pH effect an enzyme’s activity

 How enzymes work: Induced Fit Model of Enzyme Action  Enzyme reactions depend on the physical fit between the enzyme and its substrate (the reactant being catalyzed)  Active Site: portion of the enzyme that the substrate fits into  The linkage between the enzyme and the substrate causes a slight change in the enzyme’s shape which puts a strain on the substrate bonds  The enzyme releases the products and remains unchanged

 Lipids: large, nonpolar organic molecules DO NOT dissolve in H 2 0  Building blocks of lipids: Glycerol:  Functional group = -OH Fatty Acids: unbranched carbon-chains  Functional group = -COOH

Fatty Acids Continued:  Fatty acids can be saturated  (each carbon is bonded to 4 other things – “full”)  Fatty acids can be unsaturated  (when the carbon atoms form double bonds with each other in the carbon chain)

 Types of Lipids: Triglycerides: 3 fatty acids attached to a glycerol Phospholipids: 2 fatty acids attached to a glycerol, with a phosphate attached to the 3 rd carbon of the glycerol  Makes-up the cell membrane of cells Hydrophilic head 2 Fatty acid tails

 Nucleic Acids: store and transfer genetic information 3 parts of a nucleic acid:  Phosphate Group  Sugar  Nitrogenous Base Three combined forms the nucleotide 2 types of Nucleic Acids  DNA: stores genetic information for an organism  RNA: stores and transfers information from DNA that is needed to make proteins