The Chemistry of Life

Organic Chemistry ORGANIC means comes from and found in living things All organic compounds contain both Carbon and Hydrogen together Inorganic – Doesn’t contain both C and H Practice: Organic or Inorganic??? H2O = ___________ (water) NaCl = ___________ (salt) C6H12O6 = ___________ (sugar/glucose) CH4 = ______________ (methane) CO2 = _____________ (carbon dioxide) O2 = ______________ (oxygen)

Macromolecules Means “Giant molecules” Formed by polymerization: Small things (MONOMERS) join together to make large things (POLYMERS) EX. monomer + monomer + monomer = polymer Four (4) types of Organic Macromolecules: Carbohydrates Lipids Proteins Nucleic Acids VIDEO: (3:10) http://www.brainpop.com/science/matterandchemistry/bodychemistry/

Carbohydrates Elements present: Carbon, Hydrogen, Oxygen Building Blocks (and Digestive End products): Monosaccharides or Simple Sugars Example: glucose (Formula C6H12O6 ) Are found in both simple (sugars) and complex forms (starches) Function: Main Energy source

Molecular Structure of Carbs 1 Ring = MONOsaccharide BUILDING BLOCKS of complex sugars Ex. Glucose AND fructose ---------------------------------------------------------- 2 Rings = DIsaccharide Ex. lactose, maltose, and sucrose 3 or more Rings = POLYsaccharide Ex. Starch, cellulose, glycogen, chitin Polysaccharide Glucose

Making or Breaking Polymers DEHYDRATION SYNTHESIS Synthesis = building/joining Monosaccharides ARE HOOKED TOGETHER BY LOSING A WATER MOLECULE TO FORM DI AND POLYSACCS. HYDROLYSIS Hydrolysis = digestion/breaking up Polysaccharides AND Disacchararides BREAK APART BY ADDING WATER MOLECULES.

Lipids Elements present: Carbon, Hydrogen, Oxygen Building Blocks (and Digestive End products) 3 Fatty acids 1 glycerol molecule Examples Fats, oils, waxes Functions: protection and insulation Parts of CELL membranes Chemical messengers (hormones)

Types of Lipids Unsaturated Fat Saturated Fat: LIQUID at room temp (ex. Olive oil) may lower cholesterol levels Saturated Fat: SOLID at room temp (ex. Butter) may lead to heart disease or hardening of the arteries Bad for you Good for you

Proteins Elements present: Carbon, Hydrogen, Oxygen, and Nitrogen Building blocks (and Digestive End products) Amino Acids Amino acids are linked in any order and in any number to make endless numbers of proteins! Proteins are formed at the ribosomes of a cell and held together by peptide bonds. The shape determines the function Amino acid

Function and (examples) of proteins: growth and repair transport (hemoglobin) form bone and muscle (collagen) sends signals (hormones-insulin) Defense (makes antibodies) Control rates of reactions (enzymes)

Nucleic Acids Basic Building Blocks: Elements present: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus Basic Building Blocks: NUCLEOTIDES Let’s look closer at one nucleotide Nucleotides have 3 parts Phosphate Ribose sugar Nitrogen Base (1 of 4)

Each nucleotide is also connected to another above and below. Each nucleotide is connected across to another nucleotide Each nucleotide is also connected to another above and below. This forms the Double-helix molecule

Types of Nucleic Acids: DNA (Deoxy-ribo-Nucleic-Acid) RNA (Ribo-Nucleic-Acid Functions: Store and transmit GENETIC information

Group activity Create a graphic organizer, using the template below as a starting point, in order to organize important information regarding the four major organic molecules. Include (minimally): What is the molecule made of? What is its function(s)? Examples (general or specific)?

Acids and Bases: used for different functions in body (such as digestion). pH is different in different parts of body, like acid (pH 3) in stomach and basic (pH 8) in small intestines VIDEO: (3:49) http://www.brainpop.com/science/matterandchemistry/phscale/

Characteristics of Acids Any compound that GIVES OFF H+ ions in solution Ex. HCl H+ and Cl- Traits: Sour taste pH value less than 6.9 Strong acids 1-3 Common acids: Juices, vinegar, HCl Add water

Characteristics of Bases Any compound that GIVES OFF OH- ions in solution Ex. NaOH Na+ and OH- Traits: Slippery PH greater than 7.1 Strong base pH 11 - 14 Common Bases: Soaps, detergents, ammonia Add water

pH scale: measures the strengths of acids and bases. pH 0-6.9 = acid pH 7.1-14 = base pH 7 = neutral (water).

Chemical Indicators - Are used to test for certain substances Lugol’s solution (iodine) Tests for starch Yellow = no starch Blue/Black = starch Benedict’s solution Tests for monosacchardies (ie. Glucose) Blue = no glucose A diff. color = glucose Positive Test Negative Test

3. Litmus paper Tests for Acids or bases Red change = acidic Blue change = basic 4. Bromothymol blue Test for carbon dioxide Blue = basic (>7.6 pH ) Green = neutral (~7 pH) Yellow = acidic (< 6.0 pH )

Let’s Practice ……pH activity http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks3/science/acids/

The biological catalyst of life Enzymes Click for Discovery channel video The biological catalyst of life

Enzymes…. are protein substances that are necessary for: The chemical reactions that occur in your body Ex. Pepsin (enzyme) breaks protein down in the stomach. Help to release energy in the form of ATP (adenine tri-phosphate) to the cells

Enzyme Vocabulary Enzymes end in –ase Catalyst: Maltase binds to maltose Lactase binds to lactose Lipase breaks down fat Amylase is found in saliva Catalyst: Substance that affects the rate of a chemical reaction WITHOUT BEING ALTERED Because it is not altered, can do same thing over, and, over, and, over, and over……. Enzymes are ORGANIC CATALYSTS

Enzyme Vocabulary Substrate: Active site: Denature: The substance upon which the enzyme reacts Active site: Site where enzyme binds to substrate Denature: When enzyme’s shape is altered due to: high temp strong acids or bases

DEMO How Do Enzymes Work? The enzyme has an active site which has a on its surface which has a very specific shape. The enzyme and the substrate (what enzymes acts upon) temporarily join together forming the enzyme substrate complex. DEMO

Importance of Enzyme Shape Enzymes have specific shapes This means enzymes are specific to their substrate They will only attach to a substrate that “fits” their shape If shape of enzyme is denatured, will it be able to bind to its substrate? NO! Two things can cause denaturing: Temperature pH

Enzyme-Substrate Complex Formed when enzyme binds to substrate Very specific

Lock and Key Model: Enzyme-substrate complex often compared to a lock and key. Active site on enzyme can only “FIT” or bind to a specific substrate Example: Amylase will bind to starch, but not cellulose http://www.youtube.com/watch?v=PILzvT3spCQ&feature=fvwrel

What factors influence Enzyme Action? Remember, enzymes speed up reactions What can affect the rate at which enzymes perform? It’s shape! Denaturing affects rate The amount of enzyme and substrate!

Temperature - Enzyme shape and reaction rate: Enzymes have a specific temperature range at which they work best EX. Human enzymes work best at 37°C Temps not in the optimal range will cause enzymes to denature Shape is altered, so reaction rates are SLOWED or stopped altogether Reaction rates will DROP dramatically depending on how much denaturing of enzyme

Temperature vs. Reaction Rate

pH - Enzyme shape and reaction rate: Enzymes have a specific pH range at which they work best EX. Most enzymes work best at pH 7 Where in the body would enzymes be optimal at a low (acidic) pH? Why? In stomach, this is because stomach acid has a low pH pH not in the optimal range will cause enzymes to denature Shape is altered, so reaction rates are SLOWED or stopped altogether Reaction rates will DROP dramatically depending on how much denaturing of enzyme.

pH vs. Reaction Rate 3 9

Concentration - Enzyme amount and reaction rate: Enzyme rate also depends on the amount of enzyme and substrate Little enzyme, lots of substrate: Slower rates How can we speed up the rate? Add more enzyme until max. rate achieved.

Substrate Concentration vs. Reaction Rate