Transcript Macromolecules & Enzymes

The Chemistry of Life
What are living
creatures made
of?
Regents Biology
Day 1
Chapter 2
Atoms, Compounds and Molecules
 Atom - Smallest and basic unit of matter.
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3 subatomic particles:
 Neutron, proton and electron
 Compound – 2 or more different elements
chemically combined.
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Ex: salt, water, carbon dioxide
 Molecule – smallest unit of a compound
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Ex: 2H2O = 2 molecules of water
Elements of Life
 96% of living
organisms are
made of:
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carbon (C)
hydrogen (H)
oxygen (O)
nitrogen (N)
CHON!
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Molecules of Life
 Put C, H, O, N together in different
ways to build living organisms
 What are bodies made of?
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carbohydrates
 sugars & starches
proteins
 fats (lipids)
 nucleic acids
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 DNA, RNA
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What macromolecules are used
in biology?
Think of the nutrients you eat!
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Carbohydrates
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Atoms present – C, H, and O
Function: Major energy source by cells
Structural uses – cellulose, cell receptors
Monosaccharides (monomers) – single sugar units.
ex: glucose, galactose, fructose
Disaccharides (polymers) – double sugar units
ex: sucrose, lactose, maltose
Polysaccharides (polymers)– more than 2 sugar
units. ex: starch, glycogen, cellulose
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Carbohydrates
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Lipids
Fats, oils, triglycerides, waxes, and steroids
Molecules made of C, H and O.
Lipid units: 1 Glycerol and 3 Fatty Acids
Hydrophobic and non-polar
Functions: Insulation, membrane structures,
hormones, padding and waterproof coverings.
Saturated – no double bonds, solid animal
fats
Unsaturated – one double bond, oils (from plants)
*no monomer units here! They do not repeat
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Proteins
 Polymers containing:
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N, C, H and O.
 Amino acids = monomers
 A Peptide bond holds 2 amino acids
together.
 Functions: Control the rate of reaction,
regulate cell processes, form bones,
muscles, fibers, hair/nails, transport
substances to fight disease.
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Nucleic Acids
 Polymers – containing
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H, O, N, C, and P
Nucleotides
(monomers) --- sugar,
phosphate, and a
nitrogenous base
Function: Stores and
transmits hereditary
information
 Types: DNA and RNA
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 You Are
What You
Eat!
Macromolecules
AP Biology
Day 2
How do we make molecules?
We build them!
Regents Biology
2006-2007
Building large organic molecules
 Small molecules = monomers
 Bond them together = polymers
Regents Biology
Building important polymers
Carbohydrates = built from sugars
sugar – sugar – sugar – sugar – sugar – sugar
Proteins = built from amino acids
amino amino amino amino amino amino
acid – acid – acid – acid – acid – acid
Nucleic acids (DNA) = built from nucleotides
nucleotide – nucleotide – nucleotide – nucleotide
Regents Biology
How to build large molecules
 Dehydration Synthesis
Taking water out to put
the monomers together
 building cells & bodies
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Example of dehydration synthesis
amino acids
protein
 Proteins are synthesized by bonding amino acids
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amino acids = building block
protein = polymer
How to take large molecules apart
 Hydrolysis
taking big molecules apart using water
 getting raw materials
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 for synthesis & growth
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Example of hydrolysis
starch
glucose
 Starch is digested to glucose
Regents Biology
Day 3
Enzymes
Special proteins that make our
processes run faster….
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Chemical Reactions
 The changing of one set of chemicals into
another set of chemicals
 Reactants start the reaction.
 Products are produced by the reactants.
Ex: CO2 + H2O
H2CO3
Reactants
(before arrow)
Products
(after arrow)
 Activation energy: amount of energy needed
to get a reaction started
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Enzymes
(biological catalysts)
 A catalyst is a substance that speeds up a
chemical reaction by lowering the required
activation energy to run the reaction.
 Enzymes are very specific for certain
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chemical reactions.
ex: lactase works only on lactose!
Enzymes are never used up, can be reused.
 To Denature an enzyme/protein = To Destroy it
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Enzymes
(biological catalysts)
Enzyme Names
1. End in “–ase”
2. Ex: sucrase, lactase
Enzyme Action
1.
Enzymes provide a site where substrates
(reactants) can react using less energy by
lowering the activation energy
Enzymes & Substrates
= Lock & Key
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Effects of Enzymes
Reaction pathway
without enzyme
Activation energy
without enzyme
Activation
energy
with enzyme
Reactants
Reaction pathway
with enzyme
Products
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How Do Enzymes Work?
 Substrates = The reactants the enzyme
works on.
 Active sites = place on enzyme where
reactants bind.
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Enzyme Regulation
 Enzyme activity
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can be altered by
changing
working
conditions.
Ex: pH and
temperature
Cells can make
other proteins to
turn “on or off”
an enzyme.
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