Biochemistry ______________ - A substance consisting entirely of one type of atom, for instance, carbon, hydrogen or oxygen. Elements can combine into compounds to form other substances. ________ – an atom or group of atoms that have a charge ____________ - A substance consisting of more than one atom or one type of element, e.g. carbon dioxide is a compound. pH scale - scale is commonly used over a range 0 (acidic) to 14 (basic). Acid - Substances that have a pH of lower than 7 (neutral) that can dissolve in water. Base - Substances that have a pH of higher than 7 (neutral) that can dissolve in water. Metabolism • Metabolism: All the chemical reactions that occur in within the cells. • _______________: Basic subunit used to build larger molecules. Eg. Amino acids • _______________: Molecules composed of many basic subunits bonded together – Eg. Many amino acids bond together to form protein. 1 • Isomer - A chemical with the same number and types of atoms as another chemical, but possessing different properties. _____________________ - Complex chemicals broken down into smaller units E.g. Breaking down food ________________________- Small units combine to make larger molecules E.g. Plants and photosynthesis 2 ___________________________ The process by which larger molecules are formed by the removal of water from two smaller molecules. ____________________ The process by which a larger molecule is broken down into two smaller molecules. Water is taken up at the broken bond site. _____________ Compounds - contain carbon atoms that are linked together _____________ Compounds - do not contain linked carbon atoms. There are 4 major types of organic molecules important in biology. – _________________ • monosaccharides, disaccharides, polysaccharides – _________________ • Triglycerides, Phospholipids, Waxes, Steroids – _________________ • Primary, Secondary, Tertiary, Quaternary – _________________ • DNA, RNA 3 Carbohydrates Monosaccharides Disaccharides Polysaccharides • Characteristics – A Carbohydrate can be a single sugar or a polymer of many sugars. – Carbohydrates contain CHO – Carbon, Hydrogen, Oxygen – Ratio of carbon, hydrogen, oxygen = 1:2:1 • Purpose – _________________________ – _________________________ 4 Purposes of Carbohydrates Structural Major structural component of cell organelles, membranes and cytoplasm Energy Produced by photosynthesis, carbohydrates are the major energy source for cells. Energy is released through cell respiration Monosaccharides • Monosaccharides – Single sugar = _______________ – Three common isomeres • ____________ – blood sugar • ____________ – fruit, honey, twice as sweet as glucose • ____________ – milk sugar, rarely found alone. 5 Disaccharides • Formed by the joining of 2 monosaccharides – Process called ____________________________ • Three Common Isomers – _____________ • Glucose + Fructose • sugar cane, table sugar – _____________ • Glucose + Glucose • found in seeds of germinating plants – _____________ • Glucose + Galactose • Found in milk • Lactose Intolerance is common 6 Polysaccharides Important Polysaccharides • Formed by the union of may monosaccharides by dehydration synthesis • Types: – _______________ • Multiple sub-units of glucose • Storage form of energy in plants – _______________ • Branched chains of glucose • Storage of of glucose in animals – liver and muscle cells • High Blood Glucose -- __________________________ • Low Blood Glucose -- ___________________________ 7 Cellulose • Structural material found in plant cell walls • glucose is linked together differently compared to starch and therefore only organisms with cellulase can digest it. – Microbes in cow’s first stomach cleave the bonds with cellulase – The cow regurgitates (vomits into his own mouth) – chews again (gross!) – swallows into second stomach (yummy) • What is it good for?? – Roughage -- retains water in feces = soft poo Lipids Structure Contains CHO Ratio of H to O is greater than 2 to 1 Purpose ________________________ 1 gram of lipids contains > twice the calories compared to carbohydrates or proteins ____________________________ cell membranes cushion for organs carriers for vitamins 8 Types of Lipids A. Triglycerides Formed from ________________ and _________________ formed by ________________________ 1. FAT usually from animals saturated fatty acids only contain single bonds Very Stable – hard to break down solid or semi-solid at room temperature Example: Butter 2. Oil usually from plants polyunsaturated fatty acids have some double bonds between carbon atoms more reactive than fats therefore more easily broken down liquid at room temperature Example: Canola oil B. ______________________ Have a phosphate molecule attached to a glycerol backbone _____________ molecule one side is relatively hydrophilic, other side hydrophobic Major component of membranes C. Waxes Very stable ___________________________ 9 valuable waterproof coatings for plant leaves, animal feathers and fur D. Steroids structure = Four fused Carbon Rings Made from ________________ Read: Fats and Health (Page 248) Proteins After water ______________ is the most abundant molecule in body 17% of body weight 1000’s of types Purpose Cell Structure Major part of muscle, skin, nerves … Required for the building, repair and maintenance of cell structure. Cell Function Chemical messenger – ________________ Transport – ______________ Movement – ___________________ Catalysis of cell reactions – ____________ Defence against foreign substances – ______________ Structure Contains ___________ and _____ Carbon, Hydrogen, Oxygen, NITROGEN 10 Terms _________________ A large molecule made of one or more polypeptide chains folded and coiled into a specific shape. ________________ polymers of amino acids arranged in a specific order and linked by peptide bonds _________________ Covalent bond between adjacent amino acids Amino Acids The structural subunit of proteins 20 Different types 8 are “essential” Cannot be manufactured by the body Must be obtained from food Structure… Types of Proteins ________________ linear arrangement of amino acids in the polypeptide (like beads on a string) ___________________ The coiling and folding of amino acid chains (polypeptides) Hydrogen bonds cause this. ___________________ 11 The coiled and folded polypeptide is further twisted into n overall 3-D shape ___________________ arrangements of polypeptide subunits, when a protein is made up of more than one polypeptide Example: hemoglobin, enzymes Protein Changes Denaturation Changes in the shape of the protein by physical or chemical factors such as heat, radiation or pH changes. Protein may uncoil or assume a new shape. Protein’s _______________ properties and _________ properties are changed. Coagulation Permanent change in the shape of the protein e.g. boiling egg white, acid in the eye. 12 Vitamins Characteristics: Organic Molecules Cannot be synthesized from food Needed in small amounts for bodily functions Minerals ______________ materials for cell structures and ____________ – calcium, iron, iodine ______________ –magnesium activates enzymes in protein synthesis Regulation body’s _______________balance—potassium Regulates the body’s __________ balance –sodium Water Most abundant molecule in the body 60% of adult weight Functions Excellent solvent Involved in chemical reactions _______________ Maintains constant body temperature 13 Chemical Tests • Chemical tests are used to determine the presence of different types of organic molecules. • Some important tests include: • • • • Benedicts Reagent Iodine Test Biuret Sudan IV Dye Benedicts Reagent • Tests for the presence of _____________________ • Negative test: After heating the benedict solution remains _________ • Positive test: After heating the blue benedict solution turns ________ _______________________ Iodine Test • Test for ____________ • Negative Test: The iodine solution remains __________ when no starch is present • Positive Test: The iodine solution turns ______________ when starch is present Biuret Test • Test for ___________________ • Biuret solution is blue • Negative Test: When added to a substance not containing protein, the solution remains _________________ 14 • Positive Test: When added to a substance containing protein, the substance _____________________ Sudan IV & translucence test • Test for ____________ • If fat is present in the sample tested, a ________________ colour will result Translucence test • The presence of fats can be detected by rubbing samples on a piece of unglazed paper 15 Enzymes • Enzymes are _____________ molecules. • Protein molecules are composed of one or more amino acid chains, folded into uniquely shaped globs. Enzymes act as CATALYSTS! Catalysts are chemicals that regulate the __________________ ___________________________________________________ Are not consumed or altered during the reaction _______________ Energy is the energy input required to initiate any reaction. Enzymes regulate cell activities (metabolism) by lowering the activation energy reactions, therefore, occur more rapidly and at lower temperatures. FUNCTION vs. SHAPE TWO THEORIES 1) LOCK & KEY THEORY • Each chemical reaction requires its own enzyme therefore “___________________________ ” concept • The enzyme forms a temporary bond with a special molecule called a ______________________ • A substrate is always… – the substance acted upon – the substance which is changing 16 • The substrate(s) must fit into the particular 3-D structure of the enzyme’s ACTIVE SITE – actual area of the enzyme that touches the substrate When the substrate and the enzyme combine or “join” at the active site, the tandem is called an _____________________________ The ENZYME-SUBSTRATE COMPLEX then separate into product(s) and enzyme • Note that: – The enzyme remains ______________ and ready to react again with a new substrate. 17 Same old enzyme Brand New Substrate The substrate has been turned into products. INDUCED FIT MODEL • Improved Theory – 1973 – suggests that the shape of the active site does NOT __________ ___________________________________________________ – The substrate forces its way into the enzyme – This makes for a tighter fit – The orientation of the substrate molecules in the ENZYMESUBSTRATE COMPLEX helps speed up the chemical reaction by adding stress to bonds more easily bringing reactive sites physically closer together • Once a bond is formed (or broken) in substrate(s) then products are released and the _____________________ UNCHANGED and may be ______________! – A single enzyme can catalyze several million reactions in one minute 18 – The same enzyme may also catalyze the reverse reaction • The net result is that a ___________________ is converted into a multi-step reaction, therefore, lowering the_________________ – the minimum amount of energy required to initiate a chemical reaction. Naming Enzymes Enzymes are named after the substrate which it acts upon To name an enzyme, usually, the suffix “ase” is added to the end of the substrate name. For example: Substrate Enzyme Regulation of Enzyme Activity METABOLIC PATHWAYS cellular processes that involve many steps are controlled by enzymes one enzyme for each step. Allosteric Activity a change in an enzyme caused by the binding of a molecule Some enzyme’s shape may be altered by a “moderator molecule”. 19 can be a ____________ (mineral) ______________ (organic molecules) sometimes even the product molecule. Regulation of Enzyme Activity FEEDBACK INHIBITION __________________________________________________ the product of an metabolic pathway acts as a moderator on an enzyme in the series, thereby altering its shape (active site) the enzyme cannot combine with the substrate Once the moderator molecule is removed from the moderator site, the active site snaps back to its original shape. feedback inhibition ____________________________________________ _____________________________________________________________ 20 Factors Affecting Enzyme Reactions • There are four factors that affect the rate at which an enzyme can work. 1) ______________________ 2) ______________________ 3) ______________________ 4) ______________________ Temperature • In order for a reaction to occur, molecules must collide – as temperature increases, collisions increase Does the rate of reaction increase with temperature?? NO pH • Acidity or Alkalinity – the lower the number the more acidic – the higher the number the more alkaline • Enzymes have an optimal pH at which the reaction is fastest Just like with temperature, pH’s out of the optimal range will cause a decrease in rate of reaction shape of active site changes = __________________. Substrate Concentration The more substrates you have, the greater the chance the enzyme will have of combining and reacting with it. The rate does not continue to rise as you add more and more substrate. 21 There is a limit to the amount of enzyme available A substrate cannot join with the active site of an enzyme until it is free. Therefore, in an actual solution... once the number of substrate molecules exceeds the number of enzyme reaction sites, ___________________ _____________________________________________. Inhibitor Molecules Inhibitor molecules interfere with the enzyme combining with its substrate. – Competitive Inhibitor _______________________ _______________________ _______________________ = physically blocks substrate from entering active site _______________________ Inhibitor Molecules Examples: Cyanide – binds to enzyme in the Electron Transport Chain preventing formation of ATP. Carbon Monoxide – binds to hemoglobin irreversibly, therefore, no oxygen can be carried Penicillin – binds to enzyme that allows bacteria to make its protective covering, therefore, bacteria becomes susceptible to the immune system and other drugs 22 Week 10 Formative Complete the review sheet on macromolecules linked in PowerSchool and send it to me. Complete the following textbook questions and send them to me. Pg 278 #1-5, 12-15 23