BIOCHEMISTRY

CHEMISTRY OF LIFE* Elements: simplest form of a substance - cannot be broken down any further without changing what it isElements: simplest form of a substance - cannot be broken down any further without changing what it is Atom: the actual basic unit - composed of protons, neutrons, and electronsAtom: the actual basic unit - composed of protons, neutrons, and electrons

THE ATOM* Just like cells are the basic unit of life, the ATOM is the basic unit of matter.Just like cells are the basic unit of life, the ATOM is the basic unit of matter. They are very small. If placed side by side one million would stretch a distance of 1cm.They are very small. If placed side by side one million would stretch a distance of 1cm. The atom is made up of 3 particles.The atom is made up of 3 particles. ParticleCharge PROTON PROTON+ NEUTRONNEUTRAL ELECTRON-

ISOTOPES* atoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONSatoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONS Some isotopes are radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time.Some isotopes are radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time. There are several practical uses for radioactive isotopes:There are several practical uses for radioactive isotopes: 1.CARBON DATING 2.TRACERS 3.KILL BACTERIA / CANCER CELLS

COMPOUNDS* a substance formed by the chemical combination of 2 or more elements in definite proportionsa substance formed by the chemical combination of 2 or more elements in definite proportions –Ex: water, salt, glucose, carbon dioxide

TWO TYPES OF COMPOUNDS Organic - Contain C, H, and O in some ratio (usually referred to as chemicals of life)Organic - Contain C, H, and O in some ratio (usually referred to as chemicals of life) –Carbohydrates, Proteins, Lipids, Nucleic Acids Inorganic - usually "support" life - no specific ratio of C, H, and OInorganic - usually "support" life - no specific ratio of C, H, and O –Water (H2O), Carbon Dioxide (CO2)

CHEMICAL BONDS Chemical bonds hold the atoms in a molecule together.Chemical bonds hold the atoms in a molecule together. There are 2 types of chemical bonds IONIC and COVALENTThere are 2 types of chemical bonds IONIC and COVALENT

IONIC BONDS* Occur when 1 or more electrons are TRANSFERRED from one atom to another.Occur when 1 or more electrons are TRANSFERRED from one atom to another. When an atom loses an electron it is a POSITIVE charge.When an atom loses an electron it is a POSITIVE charge. When an atom gains an electron it is a NEGATIVE chargeWhen an atom gains an electron it is a NEGATIVE charge These newly charged atoms are now called IONSThese newly charged atoms are now called IONS –Example: NaCl (SALT)

COVALENT BONDS* Occur when electrons are SHARED by atoms.Occur when electrons are SHARED by atoms. These new structures that result from covalent bonds are called MOLECULESThese new structures that result from covalent bonds are called MOLECULES ** In general, the more chemical bonds a molecule has the more energy it contains** In general, the more chemical bonds a molecule has the more energy it contains SHARING IS CARING!

SOLUTION* Two parts: SOLUTE – SUBSTANCE THAT IS BEING EVENLY DISSOLVED (SUGAR / SALT)SOLUTE – SUBSTANCE THAT IS BEING EVENLY DISSOLVED (SUGAR / SALT) SOLVENT - the substance in which the solute dissolvesSOLVENT - the substance in which the solute dissolves

MIXTURES* Water is not always pure. It is often found as part of a mixture.Water is not always pure. It is often found as part of a mixture. A mixture is a material composed of TWO OR MORE ELEMENTS OR COMPOUNDS THAT ARE PHYSICALLY MIXEDA mixture is a material composed of TWO OR MORE ELEMENTS OR COMPOUNDS THAT ARE PHYSICALLY MIXED –Ex: salt & pepper mixed, sugar and sand – can be easily separated

WATER* Covalently bonded compound Due to being a polar covalent bound, can interact with a maximum 4 other water molecules through hydrogen bonding Due to this property has very unique properties 1.Cohesion, think surface tension 2.Adhesion, capillary action, climbing up plants from soil to top of trees or water soaking paper towel Other unique properties Celsius or Fahrenheit in liquid state. 2.Floats when a solid

ACIDS & BASES*(pH Lab) Acids: always (almost) begin with "H" because of the excess of H+ ions (hydrogen)Acids: always (almost) begin with "H" because of the excess of H+ ions (hydrogen) –Ex: lemon juice (6), stomach acid (1.5), acid rain (4.5), normal rain (6) Facts about Acids You eat acids daily (coffee, vinegar, soda, spicy foods, etc…)You eat acids daily (coffee, vinegar, soda, spicy foods, etc…)

ACIDS & BASES Bases: always (almost) end with -OH because of the excess of hydroxide ions (Oxygen & Hydrogen)Bases: always (almost) end with -OH because of the excess of hydroxide ions (Oxygen & Hydrogen) –EX: oven cleaner, bleach, ammonia, sea water, blood, pure water Facts about Bases Bases turn litmus BLUE.Bases turn litmus BLUE.

pH SCALE* measures degree of substance alkalinity or aciditymeasures degree of substance alkalinity or acidity Ranges from 0 to 14Ranges from 0 to 14 0 – 5 strong acid0 – 5 strong acid 6-7 neutral6-7 neutral 8-14 strong base8-14 strong base

The goal of the body is to maintain HOMEOSTASIS (neutrality) – to do this when pH is concerned, we add weak acids & bases to prevent sharp changes in pH.The goal of the body is to maintain HOMEOSTASIS (neutrality) – to do this when pH is concerned, we add weak acids & bases to prevent sharp changes in pH. These are called BUFFERSThese are called BUFFERS –Water –Protein –Kidneys

CARBOHYDRATES* (Cereal Investigation Lab) Living things use carbohydrates as a key source of ENERGY!Living things use carbohydrates as a key source of ENERGY! Plants use carbohydrates for structure (CELLULOSE)Plants use carbohydrates for structure (CELLULOSE) –include sugars and complex carbohydrates (starches) –contain the elements carbon, hydrogen, and oxygen (the hydrogen is in a 2:1 ratio to oxygen)

Monosaccharides (simple sugars) all have the formula C6 H12 O6all have the formula C6 H12 O6 all have a single ring structureall have a single ring structure –(glucose is an example)

Disaccharides (double sugars) all have the formula C12 H22 O11all have the formula C12 H22 O11 sucrose (table sugar) is an examplesucrose (table sugar) is an example

Polysaccharides Formed of three or more simple sugar unitsFormed of three or more simple sugar units Glycogen - animal starch stored in liver & musclesGlycogen - animal starch stored in liver & muscles Cellulose - indigestible in humans - forms cell wallsCellulose - indigestible in humans - forms cell walls Starches - used as energy storageStarches - used as energy storage

How are complex carbohydrates formed and broken down?

Dehydration Synthesis Combining simple molecules to form a more complex one with the removal of waterCombining simple molecules to form a more complex one with the removal of water –ex. monosaccharide + monosaccharide ----> disaccharide + water –(C6H12O6 + C6H12O6 ----> C12H22O11 + H2O Polysaccharides are formed from repeated dehydration syntheses of waterPolysaccharides are formed from repeated dehydration syntheses of water –They are the stored extra sugars known as starch

Hydrolysis Addition of WATER to a compound to SPLIT it into smaller subunitsAddition of WATER to a compound to SPLIT it into smaller subunits –(also called chemical digestion) –ex. disaccharide + H2O ---> monosaccharide + monosaccharide C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 O6

Lipids (Fats)* Fats, oils, waxes, steroids*Fats, oils, waxes, steroids* Chiefly function in energy storage, protection, and insulation*Chiefly function in energy storage, protection, and insulation* Contain carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratioContain carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio Tend to be large molecules -- an example of a neutral lipid is belowTend to be large molecules -- an example of a neutral lipid is below

Neutral lipids are formed from the union of one glycerol molecule and 3 fatty acidsNeutral lipids are formed from the union of one glycerol molecule and 3 fatty acids 3 fatty acids + glycerol ----> neutral fat (lipid)3 fatty acids + glycerol ----> neutral fat (lipid) Fats -- found chiefly in animalsFats -- found chiefly in animals Oils and waxes -- found chiefly in plantsOils and waxes -- found chiefly in plants Oils are liquid at room temperature, waxes are solidsOils are liquid at room temperature, waxes are solids Lipids along with proteins are key components of cell membranesLipids along with proteins are key components of cell membranes Steroids are special lipids used to build many reproductive hormones and cholesterolSteroids are special lipids used to build many reproductive hormones and cholesterol

PROTEINS* contain the elements carbon, hydrogen, oxygen, and nitrogencontain the elements carbon, hydrogen, oxygen, and nitrogen composed of MANY amino acid subunitscomposed of MANY amino acid subunits It is the arrangement of the amino acid that forms the primary structure of proteins.It is the arrangement of the amino acid that forms the primary structure of proteins. The structure of proteins informs of their functionThe structure of proteins informs of their function

Major Protein Functions* Growth and repairGrowth and repair Lower chemical reactions energy requirements (like lowering the time, or intensity of the stove fire to cook meat)Lower chemical reactions energy requirements (like lowering the time, or intensity of the stove fire to cook meat) Buffer -- helps keep body pH constantBuffer -- helps keep body pH constant Energy (little amount, most come from carbohydrates)Energy (little amount, most come from carbohydrates)

NUCLEIC ACIDS* in all cellsin all cells composed of NUCLEOTIDEScomposed of NUCLEOTIDES store & transmit heredity/genetic informationstore & transmit heredity/genetic information Nucleotides consist of 3 parts*:Nucleotides consist of 3 parts*: 1. 5-Carbon Sugar1. 5-Carbon Sugar 2. Phosphate Group2. Phosphate Group 3. Nitrogenous Base3. Nitrogenous Base

DNA (deoxyribonucleic acid)* contains the genetic code of instructions that direct a cell's behavior through the synthesis of proteinscontains the genetic code of instructions that direct a cell's behavior through the synthesis of proteins found in the chromosomes of the nucleus (and a few other organelles)found in the chromosomes of the nucleus (and a few other organelles)

RNA (ribonucleic acid)* directs cellular protein synthesisdirects cellular protein synthesis found in ribosomes & nucleolifound in ribosomes & nucleoli

CHEMICAL REACTIONS* a process that changes one set of chemicals into another set of chemicalsa process that changes one set of chemicals into another set of chemicals REACTANTS – elements or compounds that enter into a chemical reactionREACTANTS – elements or compounds that enter into a chemical reaction PRODUCTS – elements or compounds that are produced in a chemical reactionPRODUCTS – elements or compounds that are produced in a chemical reaction Chemical reactions always involve the breaking of bonds in reactants (Hydrolysis) and the formation of new bonds in products. (Synthesis)Chemical reactions always involve the breaking of bonds in reactants (Hydrolysis) and the formation of new bonds in products. (Synthesis)

Enzymes and Enzyme Action catalyst: inorganic or organic substance which speeds up the rate of a chemical reaction without entering the reaction itselfcatalyst: inorganic or organic substance which speeds up the rate of a chemical reaction without entering the reaction itself Enzymes*: organic catalysts made of proteinEnzymes*: organic catalysts made of protein most enzyme names end in -asemost enzyme names end in -ase enzymes lower the energy needed to start a chemical reaction. (activation energy)enzymes lower the energy needed to start a chemical reaction. (activation energy) enzyme enzyme substrate (reactants) > product

Factors Influencing Rate of Enzyme Action * (Recall Potato Lab) 1. pH - the optimum (best) in most living things is close to 7 (neutral) high or low pH levels usually slow enzyme activityhigh or low pH levels usually slow enzyme activity A few enzymes (such as gastric protease) work best at a pH of about 2.0A few enzymes (such as gastric protease) work best at a pH of about 2.0

2. Temperature - strongly influences enzyme activity optimum temperature for maximum enzyme function is usually about C.optimum temperature for maximum enzyme function is usually about C. reactions proceed slowly below optimal temperaturesreactions proceed slowly below optimal temperatures above 45 C most enzymes are denatured (change in their shape so the enzyme active site no longer fits with the substrate and the enzyme can't function)above 45 C most enzymes are denatured (change in their shape so the enzyme active site no longer fits with the substrate and the enzyme can't function)

3. Concentrations of Enzyme and Substrate ** When there is a fixed amount of enzyme and an excess of substrate molecules -- the rate of reaction will increase to a point and then level off.** When there is a fixed amount of enzyme and an excess of substrate molecules -- the rate of reaction will increase to a point and then level off.