Biology 10
Biochemistry
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Biochemistry
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 charge
Atom - The smallest particle of an element
Compound - A substance consisting of more than one atom or one type of element, e.g. carbon dioxide is a compound.
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Biochemistry
Covalent bond - Chemical bond formed by the sharing of one or more electron pairs between two atoms
Isotope - atoms containing the same number of protons but different numbers of neutrons. E.g Carbon -14
Ionic bond - Chemical bonding resulting from the transfer of one or more electrons from one atom or a group of atoms to another.
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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;
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Chemistry Review
Organic Compounds
contain carbon atoms that are linked together
Inorganic Compounds
do not contain linked carbon atoms.
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Chemistry ReviewMonomer - a simple compound whose molecules can join together to form polymers e.g. amino acids
Polymer - A large molecule consisting of chains or rings of linked monomer units e.g. protein
Dimer - a compound composed of two monomers e.g. dipeptide
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Chemistry ReviewIsomer - A chemical with the same number and types of atoms as another chemical, but possessing different properties.
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Textbook Questions
Page 159 Questions 1-8
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4 TypesThere are 4 major types of organic molecules important in Biology 20. Carbohydrates
monosaccharides, disaccharides, polysaccharides Lipids
Triglycerides, Phospholipids, Waxes, Steroids Proteins
Primary, Secondary, Tertiary, Quaternary Nucleic Acids
DNA, RNA
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Carbohydrates
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 Source of energy for cellular respiration Structural material
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Types of Carbohydrates
MonosaccharidesSingle sugar = C6H12O6
Three common isomeresGlucose
blood sugar
Fructose fruit, honey, twice as sweet as glucose
Galactose milk sugar, rarely found alone.
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Three Monosaccharides
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Three Monosaccharides
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Disaccharides
Formed by the joining of 2 monosaccharidesProcess called
DEHYDRATION SYNTHESIS
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Dehydration Synthesis
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Dehydration Synthesis
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Disaccharides
Formed by the joining of 2 monosaccharidesProcess called DEHYDRATION
SYNTHESISThe reverse process is called
HYDROLYSIS
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DisaccharidesThree Common Isomeres Sucrose
Glucose + Fructose sugar cane, table sugar
Maltose Glucose + Glucose found in seeds of germinating plants
Lactose Glucose + Galactose Found in milk Lactose Intolerance is common Bad smells from bodily orifice. (gas)
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Important Polysaccharides
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PolysaccharidesFormed by the union of many monosaccharides by dehydration synthesis
Types: Starch
Multiple sub-units of glucose Storage form of energy in plants
Glycogen Branched chains of glucose Storage of of glucose in animals
liver and muscle cells High Blood Glucose -- Glycogen formed in the liver (insulin) Low Blood Glucose -- Glycogen converted to glucose
(glucagon)
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Starch Synthesis
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Starch Synthesis
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CelluloseStructural material found in plant cell wallsglucose 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
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Lipids - think Mr. Balog’s stomach
StructureContains CHORatio of H to O is greater than 2 to 1
PurposeLong Term Energy Storage
1 gram of lipids contains > twice the calories compared to carbohydrates or proteins
Structural Materialcell membranescushion for organscarriers for vitamins
raw material for synthesis of hormones
insulator
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Classification of Lipids
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Types of Lipids
TriglyceridesFormed from 1 glycerol and 3 fatty acids formed by dehydration synthesis
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Classification of Lipids
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Triglyceride Formation
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Triglyceride Formation
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Types of Lipids
TriglyceridesFormed from 1 glycerol and 3 fatty acids formed by dehydration synthesis1) FAT
usually from animalssaturated fatty acids only contain single bondsVery Stable -- hard to break downsolid or semi-solid at room temperatureExample: Butter
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Types of Lipids
2) Oilusually from plantspolyunsaturated fatty acids have some double
bonds between carbon atomsmore reactive than fats therefore more easily
broken down liquid at room temperatureExample: Canola oil
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Types of LipidsPhospholipidsHave a phosphate molecule attached to a
glycerol backbone
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Classification of Lipids
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Types of LipidsPhospholipidsHave a phosphate molecule attached to a
glycerol backbonePolarized molecule
one side is relatively positive, other side negative
Major component of membranes
WaxesVery stable Insoluble in watervaluable waterproof coatings for plant
leaves, animal feathers and fur
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Types of Lipids
Steroidsstructure = four fused carbon rings
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Classification of Lipids
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Types of LipidsSteroidsstructure = four fused carbon rings Made from cholesterol
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Proteins
After water protein is the most abundant
molecule in body
17% of body weight
1000’s of types
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ProteinsPurposePurpose1) Cell Structure1) Cell Structure
Major part of muscle, skin, nerves …Major part of muscle, skin, nerves … Required for the building, repair and maintenance of cell Required for the building, repair and maintenance of cell
structure.structure.
2) Cell Function2) Cell Function Chemical messengerChemical messenger -- hormones -- hormones TransportTransport -- hemoglobin -- hemoglobin MovementMovement -- contractile proteins -- contractile proteins Catalysis of cell reactionsCatalysis of cell reactions -- enzymes -- enzymes Defence against foreign substancesDefence against foreign substances -- antibodies -- antibodies
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ProteinsStructureContains CHON and sometimes SCarbon, Hydrogen, Oxygen, NITROGEN
TermsProtein
A large molecule made of one or more polypeptide chains folded and coiled into a specific shape.
Polypeptide Chains polymers of amino acids arranged in a specific
order and linked by peptide bonds
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Proteins
Peptide BondCovalent bond between adjacent amino acids
Amino AcidsThe structural subunit of proteins20 Different types8 are “essential”
Cannot be manufactured by the body Must be obtained from food
Structure...
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Types of Proteins
Primaryorganized into linear arrangements
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Primary Protein
H2N
COOH
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Types of Proteins
Primaryorganized into linear arrangements
SecondaryThe amino acid chains are alpha helices -
coils and Beta pleated sheets – zigzagsHydrogen bonds cause this.
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Secondary Protein
H2N COOH
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Types of ProteinsPrimary organized into linear arrangements
Secondary The amino acid chains are alpha helices - coils and Beta
pleated sheets – zigzags Hydrogen bonds cause this.
TertiaryThe coiled molecule is further twisted into a
folded 3-D shape
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Tertiary Protein
H2N COOH
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Types of ProteinsPrimary organized into linear arrangements
Secondary The amino acid chains are coils
Hydrogen bonds cause this.
Tertiary The coiled molecule is further twisted into a folded 3-D shape
Quaternaryglobular proteins formed from the
interaction between different protein chainsExample: hemoglobin, enzymes
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Quaternary Protein
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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 physical properties and biological
properties are changed.
Coagulation Permanent change in the shape of the protein
e.g. boiling egg white, acid in the eye.
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Nucleic Acids
Involved in heredity and protein synthesis
Polymer = long chains of nucleotides
Nucleotide = sugar, phosphate, nitrogen base
Diagram:
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Nucleotide
NITROGEN BASE
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2 TypesDNADeoxyribonucleic AcidDouble Stranded HelixSugar = deoxyriboseMaster blueprint for building proteinsGenetic code in chromosomes
RNARibonucleic acidSingle StrandedSugar = ribose3 Types (Messenger, Transfer, Ribosomal)Executes DNA’s instructions
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Vitamins
Characteristics:
Organic molecules
Not used for energy construction
Cannot be synthesized from food
Needed in small amounts for bodily
functions
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Inorganic Molecules
Mineralsbuilding materials for cell structures and
hormones -- calcium, iron, iodinecoenzymes -- magnesium activates enzymes
in protein synthesis regulating body’s acid-base balance --
potassium regulates the body’s water balance -- sodium
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Inorganic Molecules
WaterMost abundant molecule in the body60% of adult weightFunctions:
excellent solvent involved in chemical reactions
Hydrolysis & dehydration synthesis
maintains constant body temperature
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Textbook Questions
Page 172 questions 9-20
Study For Your Biochemistry Exam
Will be on Monday ( also known as “Monday”)
Lab will be due on Thursday (tomorrow)