To be used with Biochemistry Guided Notes

Organic vs. Inorganic Molecules Contains Carbon (C), Hydrogen (H), and Oxygen (O) (Example: C6H12O6) Does not contain C, H, and O at same time (Example: H20) Carbon is the key element—the element of life Water: makes up 60 to 98% of living things—necessary for chemical activities and transport Carbon can bond with itself and form many times for bonds (single, double, triple and rings) Salts: help maintain water balance Example: Gatorade—electrolytes 4 Organic Molecules: Carbohydrates Lipids Nucleic Acids Proteins Acids and Bases: -pH Scale -Important for enzyme function

Carbohydrates End in -ose Sugars and complex carbohydrates (starches) Contain the carbon, hydrogen, and oxygen (the hydrogen is in a 2:1 ratio to oxygen) End in -ose

Monosaccharides Simple sugars All have the formula C6H12O6 Have a single ring structure Example: Glucose

Disaccharides Double sugars All have the formula C12H22O11 Example: sucrose (table sugar)

Polysaccharides Three or more simple sugar units Examples: Glycogen: animal starch stored in the liver and muscles Cellulose: indigestible in humans: forms cell wall in plants Starches: used as energy storage

How are complex carbohydrates formed? Dehydration synthesis: combining simple molecules to form a more complex one with the removal of water Example: monosaccharide + monosaccharide  disaccharide + water C6H12O6 + C6H12O6  C12H22O11 + H2O polysaccharides are formed from repeated dehydration synthesis

Monosaccharide + Monosaccharide 

Disaccharide + Water

How are complex carbohydrates broken down? Hydrolysis: the addition of water to a compound to split it into smaller subunits also called chemical digestion Example: disaccharide + water  monosaccharide + monosaccharide C12H22O11 + H2O  C6H12O6 + C6H12O6

Lipids Lipids (Fats): lipids chiefly function in energy storage, protection, and insulation contain carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio Examples: fats, oils, waxes, steroids Lipids tend to be large molecules

Lipids Lipids are formed from one glycerol molecule and 3 fatty acids 3 fatty acids + glycerol lipid (fat)

4 Types of Lipids Fats: from animals Saturated: solid at room temperature All single bonds in the fatty acid tail Very difficult to break down

4 Types of Lipids 2. Oils: from plants Unsaturated: liquid at room temperature Presence of a double bond in the fatty acid tail Ex. Vegetable oils

Four Types of Lipids 3. Waxes: ear wax, bees wax 

4 Types of Lipids 4. Steroids: One important molecule that is classified in this category is cholesterol High levels could lead to heart disease

Proteins Proteins: contain the carbon, hydrogen, oxygen, and nitrogen Made at the ribosomes Composed of amino acid subunits

Proteins Major Protein Functions: Usually end with -in: Growth and repair Energy Usually end with -in: Example: Hemoglobin

Making Proteins Dehydration synthesis of a dipeptide Dipeptide: formed from two amino acids amino acid + amino acid  dipeptide + water

Breaking down Proteins Hydrolysis of a dipeptide dipeptide + water  amino acid + amino acid

Proteins Polypeptide: composed of three or more amino acids These are proteins Examples: insulin, hemoglobin, and enzymes There are a large number of different types of proteins: The number, kind and sequence of amino acids lead to this large variety

Nucleic Acids Nucleic Acids: present in all cells DNA: contains the genetic code of instructions through the synthesis of proteins found in the chromosomes of the nucleus RNA: directs protein synthesis found in nucleus, ribosomes & cytoplasm

Enzymes Catalyst: inorganic or organic substance which speeds up the rate of a chemical reaction without entering the reaction itself Examples: enzymes (organic) and heat (inorganic) Enzymes: organic catalysts made of protein most enzyme names end in –ase enzymes lower the energy needed to start a chemical reaction (activation energy)

How enzymes work Enzyme forms a temporary association with a the substance it affects These substances are known as substrates. The association between enzyme and substrate is very specific—like a Lock and Key This association is the enzyme-substrate complex While the enzyme-substrate complex is formed, enzyme action takes place. Upon completion of the reaction, the enzyme and product(s) separate The enzyme is now able to be reused

Enzyme-Substrate Complex

Enzyme Terms Active site: the pockets in an enzyme where substrate fits Usually enzyme is larger than substrate Substrate: molecules upon which an enzyme acts All enzymes are proteins Coenzyme: non-protein part attached to the main enzyme Example: vitamins

Proteins in action Lock and Key Model enzyme substrate -------------> product Lock and Key Model

Factors Limiting Enzyme Action pH: pH of the environment affects enzyme activity Example: pepsin works best in a pH of 2 in stomach Amylase works best in a pH of 6.8 in mouth--saliva

Factors Limiting Enzyme Action Temperature: as the temperature increases the rate of enzymes increases Optimum Temperature: temperature at which an enzyme is most affective Humans it is 37 degrees C or 98.6 degrees F Dogs between 101 and 102 F

When Temperatures Get Too High Denature: Change in their shape so the enzyme active site no longer fits with the substrate Enzyme can't function Above 45 C most enzymes are denatured Why do we get a fever when we get sick?

General Trend vs. Denaturing

Factors Limiting Enzyme Action Concentration of Enzyme and Substrate With a fixed amount of enzyme and an excess of substrate molecules the rate of reaction will increase to a point and then level off Leveling off occurs because all of the enzyme is used up Excess substrate has nothing to combine with Add more enzyme reaction rate increases again

Enzyme-Substrate Concentration