 Biochemistry is the study of the chemical reactions that occur within living things  Our bodies are made up of different types of chemicals and molecules that all react with each other in unique ways  These reactions are the fuel for all of our life processes!

 All organic molecules MUST contain the following three elements:  Carbon, Hydrogen, and Oxygen  The key element of life is CARBON  Carbon can form many bond with itself (single, double, triple, and rings)  We identify FOUR types of organic molecules:  Carbohydrates  Lipids  Proteins  Nucleic Acids

 Does not contain carbon, hydrogen, and oxygen all at the same time  Has some of these elements, but not all  Examples:  Water- makes up 60-98% of living things  Salts- helps maintain water balance  Acids and Bases- pH scale, important for enzyme function

 Carbohydrates are sugars and complex carbohydrates (called starches)  Contain only carbon, hydrogen and oxygen  In all carbohydrates, hydrogen is in a 2:1 ratio to oxygen  Example: Glucose = C 6 H 12 O 6 Hydrogen = 12, oxygen = 6  Most carbohydrates end with the prefix: OSE  Example: Glucose, Maltose, Lactose, Sucrose

 Considered a simple sugar  They all have the formula: C 6 H 12 O 6  They all have a single ring structure  Examples: Glucose, Fructose, Galactose

 Considered a double sugar  They all have the formula: C 12 H 22 O 11  Have a double ring structure  Examples: Sucrose (table sugar), Lactose, Maltose

 Made up of three or more simple sugars  Three examples:  Starch: How plants store excess glucose, used as an energy source for humans  Glycogen: Animal starch, stored in liver and muscles  Cellulose: Indigestible in humans, forms cell wall in plants

 Dehydration Synthesis:  Dehydrate = to LOSE water  Synthesize = to make  So dehydration synthesis means combining simple molecules to form a more complex one with the REMOVAL of water  Example:

 Hydrolysis:  Hydro = Water  Lysis = To Cut  So, hydrolysis means breaking down larger molecules into smaller one, with the ADDITION of water  Also called: Chemical Digestion  Examples: Disaccharide + Water  Monosaccharide + Monosaccharide ANIMATION

 They are opposite reactions to each other!

 Lipids are also called fats  Contain the elements: carbon, hydrogen, and oxygen  Hydrogen and oxygen are NOT in a fixed ratio: that is specific to carbohydrates

 Three functions of lipids  Energy Storage  Protection (your brain is covered in fat)  Insulation (keeps you warm)  Lipids tend to be the largest of the organic molecules. They carry more energy than carbohydrates, but they are not utilized to make ATP during respiration because they are too difficult and too large to break down  Lipids also make up cell membranes!

 Lipids are composed of one glycerol molecule and three fatty acids

 Dehydration synthesis adds each fatty acid to the glycerol molecule  Hydrolysis is used to break them down

 Saturated fats are solids at room temperature  They typically come from animals  They are solids because all of the bonds between carbon atoms in the fatty acid tails are SINGLE bonds, so each lipid molecule is able to pack together very tightly  Examples: butter, cheese, Crisco

 Liquids at room temperature  Typically come from plants  They are liquids because at least one of the bonds between the carbon atoms in the fatty acid tail is a DOUBLE bond. This causes a kink in the chain, so lipid molecules cannot pack together as tightly.  Examples: vegetable oil, olive oil

 Contain the elements: carbon, hydrogen, oxygen, and nitrogen  Made in the ribosomes  Composed of small subunits call amino acids  Contain an amino group (NH3) and a carboxyl group (COOH)  Main functions of proteins are growth, repair, and energy

 A molecule composed of three or more amino acids is called a polypeptide  The chemical bond between two amino acids is called a peptide bond

 Dehydration synthesis joins two amino acids together to form a DIPEPTIDE

 There are 20 different amino acids  These 20 amino acids can be joined together in countless different combinations and sizes (like the 26 letters of the alphabet)  This accounts for the large number of different types of proteins that exist!

 Organic molecule that carries genetic information  Examples: DNA, RNA  Contains the elements: carbon, hydrogen, oxygen, nitrogen, and phosphorus  Composed of small subunits called nucleotides

 Each nucleotide is composed of:  A Sugar  A Phosphate Group  A Nitrogen Base

1. What is the difference between an organic and an inorganic molecule? 2. What organic molecule is composed of hydrogen and oxygen in a 2:1 ratio? Organic = Must contain elements carbon, hydrogen, and oxygen Inorganic = Contains two of the three elements, but not all three at the same time Carbohydrate

1. What is the difference between dehydration synthesis and hydrolysis? Dehydration Synthesis creates larger molecules from smaller ones with the REMOVAL of water Hydrolysis breaks down larger molecules into smaller ones with the ADDITION of water

 Is the following molecule a monosaccharide, disaccharide, or a polysaccharide? Disaccharide

 What type of organic molecule is shown below? Lipid Is this lipid saturated or un saturated? Saturated

 A catalyst is a substance that speeds up the rate of a chemical reaction, without entering the reaction itself  Catalysts can be  Inorganic- heat  Organic- enzymes  Most catalysts are organic!

 An enzyme is an organic catalyst made of proteins  Most enzymes end in –ase  Enzymes work by lowering the activation energy of chemical reactions. This means it lowers the amount of energy needed to start a chemical reaction, so it occurs faster!  Example: lipases breaks down lipids, proteases break down proteins

 Enzymes act on molecules called substrates  Enzymes fit into their substrates like a lock fits into a key- it is VERY SPECIFIC  This is called the lock and key model  The active site is the pocket within an enzyme where the substrate fits  Typically, enzymes are larger than their substrates Animated Introduction to Enzymes

 1. Enzyme joins with substrate  2. Enzyme and substrate fit together like a lock and key, forming an enzyme-substrate complex  3. Enzyme action takes place  4. Enzyme and products separate. The enzyme is unchanged and can be reused!

 Enzymes can be very picky! They only work under very specific conditions.  The following factors all affect the rate (speed) in which an enzyme will work:  pH  Temperature  Concentration of enzymes and substrates

 The pH scale measures how acidic and basic a solution is  A pH value less than 7 is considered acidic  A pH value greater than 7 is considered basic  Water is considered neutral, with a pH of 7

 Different enzymes work at different pH’s  Pepsin, an enzyme that breaks down proteins, works best at a pH of 2. Why?  Amylase, an enzyme that breaks down carbohydrates, works best at a pH of 6.8. Why?

 Typically, as temperature increases, enzyme action also increases  All enzymes have an optimum temperature, or a temperature at which the enzyme is most effective  Optimum temperature for humans is 98.6 ⁰F  Optimum temperature for dogs is ⁰F

 When temperatures are too high, enzymes begin to change shape  When an enzyme changes shape it is called a denatured enzyme  If an enzyme changes shape, it can no longer fit with its substrate, so it cannot function

 As concentration of both the enzyme and the substrate increases, the rate of enzyme action increases to a certain point, and then it will level off

 If the concentration of the enzyme increases, reaction rate will initially increase. However, as all of the substrate is broken down, the excess enzymes have nothing to combine with, so reaction rate levels off.  If the concentration of the substrate increases, reaction rate will initially increase. However, as all of the enzyme is used up, the excess substrates then have nothing to combine with, so reaction rate levels off.

 What is an enzyme?  How does it work? An organic catalyst that speeds up the rate of a chemical reaction. It works by lowering the activation energy of a chemical reaction.

 What is the lock and key model of enzyme action?  What are three factors that affect the rate of enzyme action? All enzymes fit into their substrates in a very specific manner. They fit like a lock and key. Temperature, pH, concentration