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.
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• 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
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___________________________
 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
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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
– _________________________
– _________________________
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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.
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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
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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 -- ___________________________
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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
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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
 ___________________________
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 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
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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.
___________________
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 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.
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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
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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 _________________
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• 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
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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
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• 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.
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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
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– 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”.
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 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 ____________________________________________
_____________________________________________________________
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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.
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 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
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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
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