2 Explain how the human digestive and respiratory system exchange energy and matter with the environmentDescribe the chemical nature of carbohydrates, lipids, and proteins and their enzymes.
3 Biochemistry Atom - The smallest particle of an element Element - A substance consisting entirely of one type of atom, for instance, carbon, hydrogen or oxygen. Elements can combine into compounds to form other substances.Ion – an atom or group of atoms that have a chargeCompound - A substance consisting of more than one atom or one type of element, e.g. carbon dioxide is a compound.
4 BiochemistryCovalent bond - Chemical bond formed by the sharing of one or more electron pairs between two atomsIonic bond - Chemical bonding resulting from the transfer of one or more electrons from one atom or a group of atoms to another.
5 BiochemistrypH 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.Buffer - Solution that resists change in pH;
6 MetabolismMetabolism: All the chemical reactions that occur within the cells.Monomer: Basic subunit used to build larger molecules. Eg. Amino acidsPolymer: Molecules composed of many basic subunits bonded togetherEg. Many amino acids bond together to form on protein.
12 Dehydration Synthesis The process by which larger molecules are formed by the removal of water from two smaller molecules.+H20
13 HydrolysisThe process by which a larger molecule is broken down into two smaller molecules. Water is taken up at the broken bond site.+H20
14 Chemistry Review Organic Compounds Inorganic Compounds contain carbon atoms that are linked togetherInorganic Compoundsdo not contain linked carbon atoms.
15 4 TypesThere are 4 major types of organic molecules important in biology.Carbohydratesmonosaccharides, disaccharides, polysaccharidesLipidsTriglycerides, Phospholipids, Waxes, SteroidsProteinsPrimary, Secondary, Tertiary, QuaternaryNucleic AcidsDNA, RNA
17 Types of Carbohydrates MonosaccharidesDisaccharidesPolysaccharides
18 Carbohydrates Characteristics Purpose A Carbohydrate can be a single sugar or a polymer of many sugars.Carbohydrates contain CHOCarbon, Hydrogen, OxygenRatio of carbon, hydrogen, oxygen = 1:2:1PurposeSource of energy for cellular respirationStructural material
19 Purposes of Carbohydrates StructuralMajor structural component of cell organelles, membranes and cytoplasmEnergyProduced by photosynthesis, carbohydrates are the major energy source for cells. Energy is released through cell respiration
30 Disaccharides Formed by the joining of 2 monosaccharides Process called DEHYDRATION SYNTHESISThe reverse process is called HYDROLYSIS
31 Disaccharides Three Common Isomers Sucrose Maltose Lactose Glucose + Fructosesugar cane, table sugarMaltoseGlucose + Glucosefound in seeds of germinating plantsLactoseGlucose + GalactoseFound in milkLactose Intolerance is common
34 Important Polysaccharides StructuralStorageStarchGlycogenCelluloseChitinExoskeletons...
35 PolysaccharidesFormed by the union of may monosaccharides by dehydration synthesisTypes:StarchMultiple sub-units of glucoseStorage form of energy in plantsGlycogenBranched chains of glucoseStorage of of glucose in animalsliver and muscle cellsHigh Blood Glucose -- Glycogen formed in the liverLow Blood Glucose -- Glycogen converted to glucose
36 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 cellulaseThe 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
38 Lipids Structure Purpose Contains CHO Ratio of H to O is greater than 2 to 1PurposeLong Term Energy Storage1 gram of lipids contains > twice the calories compared to carbohydrates or proteinsStructural Materialcell membranescushion for organscarriers for vitaminsraw material for synthesis of some hormonesinsulator
39 Classification of Lipids PhospholipidSteroidTriglyceride
40 Types of Lipids Triglycerides Formed from 1 glycerol and 3 fatty acids formed by dehydration synthesis
41 Classification of Lipids PhospholipidSteroidTriglyceride
45 Types of Lipids Triglycerides Formed from 1 glycerol and 3 fatty acids formed by dehydration synthesis1) FATusually from animalssaturated fatty acids only contain single bondsVery Stable -- hard to break downsolid or semi-solid at room temperatureExample: Butter
46 Types of Lipids 2) Oil usually from plants polyunsaturated fatty acids have some double bonds between carbon atomsmore reactive than fats therefore more easily broken downliquid at room temperatureExample: Canola oil
48 Types of Lipids Phospholipids Have a phosphate molecule attached to a glycerol backbone
49 Classification of Lipids PhospholipidSteroidTriglyceride
50 Types of Lipids Phospholipids Waxes Have a phosphate molecule attached to a glycerol backbonePolarized moleculeone side is relatively hydrophilic, other side hydrophobicMajor component of membranesWaxesVery stableInsoluble in watervaluable waterproof coatings for plant leaves, animal feathers and fur
56 Proteins After water, protein is the most abundant molecule in body 17% of body weight1000’s of types: species specific and individual specific
57 Proteins Purpose 1) Cell Structure 2) Cell Function Major part of muscle, skin, nerves …Required for the building, repair and maintenance of cell structure.2) Cell FunctionChemical messenger -- hormonesTransport -- hemoglobinMovement -- contractile proteinsCatalysis of cell reactions -- enzymesDefence against foreign substances -- antibodies
59 Proteins Structure Terms Contains CHON Carbon, Hydrogen, Oxygen, NITROGENTermsProteinA large molecule made of one or more polypeptide chains folded and coiled into a specific shape.Polypeptide Chainspolymers of amino acids arranged in a specific order and linked by peptide bonds
60 Proteins Peptide Bond Amino Acids Covalent bond between adjacent amino acidsAmino AcidsThe structural subunit of proteins20 Different types8 are “essential”Cannot be manufactured by the bodyMust be obtained from foodStructure...
64 Levels of Protein Structure Primary protein structurelinear arrangement of amino acids in the polypeptide (like beads on a string)exact sequence of amino acids determines overall protein structure (analogy: different arrangements of letters spell out words with different meanings)all proteins have primary structure
66 Levels of Protein Structure Secondary Protein StructureThe coiling and folding of amino acid chains (polypeptides)coils are like springsfolding produces sheet-like structurethis type of structure is held together by hydrogen bonding between amino acidsSome proteins have lots of secondary structure, some have none
68 Levels of Protein Structure Tertiary Protein StructureThe coiled and folded polypeptide is further twisted into n overall 3-D shapeShape held together by hydrogen bonds, covalent bonds, ionic bondsRefers to the polypeptide as a wholePolypeptides may have an overall shape (tertiary structure) that is eitherGlobular (like a big blob), orHelical (like a long, coiled spring)
70 Levels of Protein Structure Quaternary Protein Structurearrangements of polypeptide subunits, when a protein is made up of more than one polypeptideHeld together by hydrogen bonds, ionic bonds, covalent bondsExample: hemoglobin, many enzymes
72 (a) The primary structure of a protein is the sequence of amino acids in the polypeptide strand. (b) Hydrogen bonds that form with nearby amino acids coil and fold the polypeptide into α-helices and β-pleated sheets; these constitute the polypeptide’s secondary structure.(c) The polypeptide folds further to form its tertiary structure. These folds are stabilized by R-group interactions.(d) The clustering of two or more polypeptides in a tertiary structure generates the quaternary structure of a protein.
73 Protein Changes Denaturation Coagulation 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 physical properties and biological properties are changed.CoagulationPermanent change in the shape of the proteine.g. boiling and cooling egg white
75 Vitamins Characteristics: Organic molecules Not used for energy constructionCannot be synthesized from foodNeeded in small amounts for bodily functions
76 Inorganic Molecules Minerals building materials for cell structures and hormones -- calcium, iron, iodinecoenzymes -- magnesium activates enzymes in protein synthesisregulating body’s acid-base balance -- potassiumregulates the body’s water balance -- sodium
77 Inorganic Molecules Water Most abundant molecule in the body 60% of adult weightFunctions:excellent solventinvolved in chemical reactionshydrolysismaintains constant body temperature
79 Chemical TestChemical tests are used to determine the presence of different types of organic molecules.Some important tests include:Benedicts ReagentIodine TestBiuretSudan IV Dye
80 Benedicts Reagent Tests for the presence of simple sugars Negative test: After heating the benedict solution remains bluePositive test: After heating the blue benedict solution turns yellow to orange.
81 Benedicts Test Negative Test: Blue Positive Test: Orange No simple sugar is presentPositive Test: OrangeSimple sugar is present
82 Iodine Test Test for Starch Negative Test: The iodine solution remains amber when no starch is presentPositive Test: The iodine solution turns blue black when starch is present
83 Iodine Test for Starch Positive Test: Solution turns blue black Starch is presentNegative Test: Solution remains amberNo starch in present
84 Biuret Test for Protein Biuret solution is blueNegative Test: When added to a substance not containing protein, the solution remains bluePositive Test: When added to a substance containing protein, the substance turns purple
85 Biuret Test for Protein Negative Test: Solution remains bluePositve Test: Solution turns violet
86 Sudan IV & translucence test Test for fatsIf fat is present in the sample tested, a red or pink colour will resultTranslucence testThe presence of fats can be detected by rubbing samples on a piece of unglazed paper