Ch 2 Chemistry Review

• Atom- smallest stable units of matter• Subatomic Particles: • Protons- + charge, nucleus• Neutrons- no charge, nucleus• Electrons- - charge, outer shells

• Atomic #- # of protons• Atomic Mass- # protons + # neutrons

• Ionic Bonds- (ion = charged atom)• Atoms lose or gain electrons and become charged• Cations=+• Anions=-• Ions of opposite charges form ionic bonds

• Covalent Bonds• Atoms share pairs of electrons• Strongest bonds

• Polar=unequal: hydrophilic• Nonpolar=equal: hydrophobic

• Hydrogen Bonds• Weak attraction between polar molecules• Slightly – end attracted to slightly + end of different polar molecules

Chemical Reactions• new chemical bonds form between atoms or existing bonds are broken

• Metabolism- all reactions occurring in cells/tissues at a given moment

• Decomposition- reactions that break down molecule into smaller fragment• Ex: hydrolysis- bond is broken and (H & OH) are added to fragments• Catabolism- rxns within the body’s cells & tissues, break covalent bond, releases

kinetic energy that = work

• Synthesis- opposite of decomposition, assembles smaller molecules into larger ones• Ex: dehydration synthesis- removal of water• Anabolism- rxns within the body’s cells & tissues, take energy to create a bond,

“uphill”

• Enzymes- catalysts, speed up rxns• Metabolism- make it possible for our bodies to break down foods without

harsh temps.• Promote chemical rxns by lowering the activation energy requirements

• pH- Acidic vs Basic• Unregulated pH > break chemical bonds, change the shapes of complex

molecules, disrupt cell tissue & functions• Regulated by buffers (bicarbonate)- stabilize the pH of a solution by removing

or replacing H+ ions• Inorganic compounds help regulate pH

• Inorganic- H2O, O2, vitamins, electrolytes

• Organic molecules- C & H, large• Monomers- single subunit• Polymers- many monomers bond together

1. Carbohydrates

• C, H, O: (1:2:1)• Energy source• Ex: • Glucose/Fructose > monosaccharide > quick energy• Sucrose/Lactose/ maltose > disaccharides > energy• Glycogen > polysaccharide > energy storage by liver

• Cellulose > Starch in plants

2. Lipids

• C, H, O(small)• Form essential structural components of all cells• Energy reserves, stored as fats• Ex:

• fatty acids• Saturated- each carbon atom in the tail has four single covalend bonds• Unsaturated-one or more of the tails has a double bond

• Eicosanoids: Leukotrienes- coordinate response to injury/disease• Prostaglandins- coordinate cell activity, pain receptors

• Glycerides > fat storage, protection• Steroids > cholesterol for plasma membrane, hormone production• Phospholipids > plasma membrane formation

3. Proteins

• Long chains of AA• F(x):

1. Support2. Movement- muscles3. Transport- lipids, gases, bind to transport proteins4. Buffering- prevent dangerous changes in pH5. Metabolic regulation- enzymes6. Coordination & control7. Defense- skin, hair, nails, antibodies

Proteins contd1. Primary- sequence of AA bonded together in a single chain2. Secondary- hydrogen bonds create either an alpha-helix or pleated sheet

structure3. Tertiary- complex coiling & folding of a secondary protein creating 3D shape4. Quaternery- 2 or more tertiary proteins associated together to form a protein

complex

• Denaturation: loss of protein structure due to high temp or extreme acids/bases• Loss of structure = loss of function

• Enzymes:• Substrates- reactants in enzymatic rxns• Active site- where rxn takes place• Promote rxns by lowering the activation E requirements

4. Nucleic Acids

• 1 or 2 long chains that are formed by dehydration synthesis• Subunits= nucleotides: pentose + phosphate group + nitrogenous

base• F(x): make proteins• Ex: A,T,C,G- storage or transfer of info• DNA- genetic information that controls protein synthesis• RNA- performs protein synthesis as directed by DNA• ATP- provides cells with energy to perform vital functions

Structure of High Energy Compounds1. Phosphate group2. Enzymes capable of catalyzing the rxns involved3. Suitable organic substrates to which the phosphate can be added• ATP > ADP >AMP• F(x): quick energy