Chemistry of Life Organic Compounds

The Chemistry of Life 96% of Human Body made of just four elements: C O H N Others are called trace elements such as Mg, K, Ca, Na, Zn, etc.

Don’t Forget Water! Water 65% of your body is H2O water is inorganic doesn’t contain carbon

Properties of Water Temperature Takes a great deal of ENERGY to change water temperature…. Helps organisms maintain HOMEOSTASIS! Molecule Formula Molecular mass Melting point / °C Boiling point / °C Methane CH4 16 -184 -161 Ammonia NH3 17 -78 -33 Water H2O 18 +100 Hydrogen fluoride HF 20 -92 +19 Hydrogen sulphide H2S 34 -86 -61

Properties of Water Cohesion Attractive force b/ H2O particles Provides a “skin” on surface

Properties of Water Adhesion Water provides attractive force b/ unlike substances

Acids, Bases, and pH pH scale – concentration of H+ ions ranges from 0-14 At 7, H+ and OH- ions are equal (neutral) Pure water Higher number = more basic Lower number = more acidic

Acids Compound that forms H+ ions in solution Strong acids – pH of 1-3

Bases Compound that produces OH- ions Contain lower concentrations of H+ Strong bases – pH of 11-14

Buffers Human body – pH of 6.5 – 7.5 Buffers – weak acids or bases that react with strong ones to prevent sudden changes in pH Help regulate homeostasis

So far we have discussed water in our cells and in living organisms… How much of your body is composed of water? How much is NOT water? What is this “other” stuff?

Organic Compounds… the other stuff! Make up the other parts of your body that are NOT water! What elements do you think you might find in organic compounds?

What does it mean for something to be organic? Organic – in chemistry - means it contains the element CARBON!

Organic Compounds Organic compound = a substance that contains the element carbon; organic compounds can be found in all living things

Organic Compounds Are all carbon compounds the same size? NO! Huge range… Some compounds have 1 carbon atom and others can have thousands of carbon atoms!

4 Main Organic Compounds Carbohydrate Lipids Nucleic Acid Proteins

Molecular Chains Monomer = a single unit that typically makes up a chain of molecules Example = nucleotides, monosaccharide, fatty acid Polymer = a large molecule formed when many smaller molecules bond together Example – polysaccharide, oils, polypeptide

How are polymers and monomers bonded together? Polymerization = (AKA condensation) making polymers What do you think polymers are made of?

Polymerization Why do you think “condensation” is another term for polymerization?

Can these bonds be broken? Hydrolysis = breaking down polymers into smaller compounds What do you think this might require?

4 Main Organic Compounds Carbohydrate Lipids Nucleic Acid Proteins

For each organic compound you should know: Elements that compose it Major function(s) Monomers Polymers Examples

Carbohydrates Elements that compose it: Major function(s) C, H, O In a specific 1:2:1 ratio (ex: C6H12O6 – glucose) Can be thought of as “hydrates of carbon” or C + H2O Major function(s) Quick energy (think about breakfast…)

Carbohydrates Monomers Polymers Examples Monosaccharides (simple sugars) Polymers Polysaccharides (starches) Examples Glucose, table sugar (sucrose), cellulose Usually end with “-ose” Bread, potato, candy

Organic Compounds: Carbohydrates Monomers of Carbs Disaccharide Polymers of Carbs Monosaccharide 2 monosaccharides bonded together 3+ monosaccharides bonded together Ex: glucose, fructose Ex: Sucrose (table sugar) Ex: cellulose (plant cells), glycogen (animal cells)

Sugars/Carbohydrates usually end with “-ose”

Create Diagram Carbohydrates Definition/purpose Elements which build the organic compound Carbohydrates Food Examples 3 facts about Carbs

Lipids Lipids = nonpolar fats found in living organisms Elements: C, H, O Ratio: NOT 1:2:1 (like carbohydrates) Example- CH3(CH2)7CH=CH(CH2)7CO2H  oleic acid… in olive oil Functions: long term storage, cushion, insulation, back-up energy supply

Lipids Monomers of Lipids: Fatty Acids + glycerol Polymers of lipids: Lipids

Nucleic Acid Elements: C, H, O, P, N Major function(s): Compose DNA and RNA– contain genetic information

Nucleic Acid Monomers: Nucleotides Polymers: Nucleic acids 3 parts: phosphate group, sugar (ribose), nitrogen base Polymers: Nucleic acids Examples : DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

Tell if the following are carbs, lipids, or nucleic acids: Potato Olive oil RNA Starch Bread Sucrose Glucose DNA

Proteins Elements that compose it: C, H, O, N Major function(s): structure, cell transport, long term energy storage, cell signaling,

Proteins Elements that compose it: C, H, O, N Major function(s): structure cell transport long term energy storage cell signaling cellular activities coded in genes

Proteins Monomers = amino acids Polymers = polypeptide (aka protein) POLYPEPTIDES ARE BONDED WITH A PEPTIDE BOND Examples Soy, meat, enzymes, transport proteins, pigments

Protein Structure

Types of Proteins Insulin Hemoglobin Enzymes (-ase) Metabolism and utilization of energy from nutrients Hemoglobin Transports oxygen in our bodies Enzymes (-ase) Speeds up reactions

Create Diagram for Rest… Definition/purpose Chemical Structure (smallest unit Lipid/Nucleic Acid/Proteins Food Examples 3 facts about each

Enzymes: Special Kinds of Proteins Enzyme = a protein that helps regulate chemical reactions Do this by lowering the energy required to initiate a reaction Lowering the activation energy speeds up the reaction In short: enzymes speed rxn rates by lowering activation energy

Naming Enzymes Most all enzymes end with “-ase” Belong to the protein group of organic compounds Examples: Lactase Catalase Helicase Peroxidase Hydrogenase

Enzymes are said to be CATALYSTS Catalyst = a substance that lowers activation energy required for a chemical reaction to occur

Can enzymes be affected? Yes! Can be “de-natured” or rendered unusable by changes in the cell’s physical and chemical environment 2 Major things: Temperature pH

Specific Functions in Body Break down substances quickly (saliva) Salivary amylase Speed up Reactions Lower activation energy (energy required for a reaction)

How catalysts work:

Enzymes are SPECIFIC! Lock and Key model = the model that shows that enzymes are specific to the substrates on which they act

How Enzymes Work Video http://www.youtube.com/watch?v=i6HflIPr7_g

Enzyme Terms Activation energy = energy required for the chemical reaction to occur Active site = location on enzyme where the substrate will attach Substrate = substance that is changed by an enzyme Product = the product of the enzyme reaction; the changed substrate

Other enzyme terms: Cofactors or Coenzymes - a non-protein enzyme helper Enzyme Inhibitors - chemicals which interfere with enzyme function Enzyme Enhancers - chemicals which increase enzyme function

Enzyme does NOT change after reaction! Enzyme can be re-used!

Temperature and Enzymes

pH and Enzymes