Transcript Biochemistry - Bishop Ireton High School

ATOMS
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Nucleus contains protons and neutrons
Proton (+ charge)
Neutron (no charge)
Electron (- charge) travel around nucleus
Atomic weight - Atomic. number = Neutrons
Atomic weight = # protons +# neutrons
Each element has different # of protons(atomic
number)
ISOTOPES
• Atoms of the same element, but with different
# of neutrons ( different weights)
• Some radioactive
• C dating (14C)
Compounds
• Substance composed of 2 or more atoms
• Stay together with bonds
• 2 types
a. Covalent
b. Ionic
Chemical Reactions
• Bonds broken and formed between
compounds
• Metabolism
• Reactant + Reactant
Product
• Reactants must equal products
ex. Mg + 2Cl = MgCl2
• Mixture- combination of substances which
retain their own properties
ex. Sand and sugar (no bonds broken)
• Solution- solute (solid) evenly distributed
in solvent (liquid)
ex. Koolaid and water
Gatorade and water
ACIDS AND BASES
• pH- measure of [H+] ions
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0-1-2-3-4-5-6-7-8-9-10-11-12-13-14
acid
neutral
base
Acid- forms [H+] ions ex. HCl- hydrochloric acid
Base- forms [OH-] ions ex. KOH- Potassium Hydroxide
WATER
• Most important substance
• 70-90% of most organisms
• Unique properties
• Polar Covalent molecule
Oxygen keeps electrons closer and Hydrogen has
electrons farther away
Causes O to have – charge
H has + charge
Amazing Water
• Polar molecule- sticks to itself (b/c of charged
molecule (cohesion and adhesion)
• Forms H bonds between 2 water molecules
• Resists temperature change- requires more heat to
raise 1 g/1°C (High Specific Heat)
• Sticks to itself-cohesion
• Sticks to other things- adhesion
• Expands when it freezes-makes it float, which makes
ice’s density <1
Life Substances
• CARBON- organic
• C has 4 outer electrons- can make 4 strong covalent
bonds
• Can form Single,double, triple bonds
• Can form chains, branched chains and rings
• Mono-(1), di- (2)
• Polymer-large molecule made of many small
molecules(called a monomer)
Carbon
• C-C
• C=C
• C= C
Polymerization
• When several monomers are joined together
to form a polymer. Polymers can have as many
as 2-2000 monomers .
• Every Carbohydrate, lipid, protein and nucleic
acid is a polymer or macromolecule. Each of
their monomers are different from the others’
monomers.
• Ex- Protein monomer- amino acid
Carbohydrate monomer- monosaccharide
CARBOHYDRATE
Sugars and Starch
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Quick energy compound
Biomolecule COH2 (simple formula)
Monosaccharide- simple sugar- glucose
Disaccharide- 2 sugars
glucose +fructose= sucrose
• Polysaccharide- Starch,
Glycogen( energy storage)
Cellulose
ISOMER
same formula,
different
structure
glucose and
galactose
C6H12O6
Dehydration synthesis
• How are 2 monomers joined together?
• A water molecule is pulled out from the 2
monomers:
1 gives up an H, the other an OH
Called dehydration synthesis
Polysaccarides
• Formed when there is an excess of glucose.
Glucose is the body’s raw material needed to
make energy. Plants get their glucose through
photosynthesis. Animals get theirs through
food.
• Plants store their excess glucose as starch or
cellulose. Cellulose is used to make cell walls.
(we can’t digest cellulose)
• Animals store their excess glucose as glycogen
in the liver and muscle cells
Hydrolysis
• When glucose levels are low plants and animals can
use their stored glucose but first they must break the
polymer up into the monomer glucose.
• This requires the reverse reaction of dehydration
synthesis. Instead of pulling out a water molecule, a
water molecule is added to break the bond.
• One monomer will get the H, the other the OH
Hydrolysis
LIPIDS
• Fats, oils, waxes, steroids
• Insoluble in water (oil and Water don’t mix)
• Made of 4 smaller molecules:a glycerol
molecule and 3 fatty acid chains(Dehydration
synthesis)
• Nonpolar
• Energy storage, coatings
Monomer lipid has 2 parts
• 3 fatty acid chains which are composed of a
long chain of carbons with H atoms
• Glycerol molecule which is an organic alcohol
that is attached to the 3FA through a DH
synthesis reaction.
LIPIDS
3 different kinds of Fatty Acids
• Saturated
• Unsaturated
• Polyunsaturated
Saturated Fats
• Fatty acid chain has all single bonded carbons.
All other bonds have H’s attached
• Unhealthy for us.
• Since all the bonds are single the molecule has
little flexibility
• Sat. Fats are solid at room temperature. Ex.Butter
Unsaturated Fats
• Have at least 1 double bond
• More flexible
• Ex. Margarine- easier to spread than butter
due to the double bonds
• Better for us
Polyunsaturated Fats
Fatty acid chains have many double bonds.
Liquid at room temp. Ex. –Oil
Better for us.
Over time saturated and unsaturated fats can
build up on the walls of our arteries and can
lead to heart disease.(Plaque)
Other uses for fats
• Sterols- special lipids that act as chemical
messengers. Ex. Cholesterol.
• Phospholipids- found as part of cell
membranes. Regulates passage of material in
and out of cell. These are unique because a
portion of the molecule is hydrophobic(the
fatty end) and the other is hydrophilic(the
phosphate end)
PROTEINS
• Large macromolecules
• Basic building material for all cell structures
• Provide structure for tissues and organs to
carry out metabolism
• Contains N
• Involved in muscle contraction, transporting
oxygen, enzymes
AMINO ACIDS
• Building block of all proteins(20 AA)
• AA join by making peptide bondloss of H2O H----OH
• Make all thousands of proteins
3 parts of Amino Acid
• Amino group- NH2
• Carboxyl group-COOH
• R group- R groups are different for each of the
20 amino acids.
Amino Acid
• The smallest protein is a di peptide which
consists of 2 amino acids linked together by a
peptide bond.
• Polypeptide: long chain of amino acids
bonded by peptide bonds
Peptide bond
Quaternary structure
of Proteins
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1- sequence of amino acids
2- bending and coiling
3-Folds in on itself
4-Binds with other proteins
Uses for proteins
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Construct many parts of the cell
As hormones such as insulin
Transport oxygen-hemoglobin
Special proteins called ENZYMES-these speed
up reactions in the body so they happen
quickly.
Enzymes
• Every chemical reaction must be started or
ignited with ACTIVATION ENERGY.
• In most chemical reactions this AE is in the
form of heat
• This heat energy moves the reactants called
SUBSTRATES around causing them to bump
into each other.
• In the body, heat can’t be used as AE because
it would harm the body.
• We need a different AE-called ENZYMES
• Enzymes join with substrates and bring them
together.
• This happens at the enzymes active site.
• Enzymes do their job and then move on to
next reaction.
• They do not become part of the product.
• They remain unchanged.
• Enzymes are SUBSTRATE SPECIFIC:
there is a specific enzyme for each substrate.
They must fit perfectly like a “lock and key”
ENZYMES
• Speed up rxns
• Depends on temp,
concentration, pH
• Substrate specific
• Lock and key
• No change to enzyme
• Most End in ase (lactase
breaks down lactose)
• 1000’s of reactions every minute
• Enzymes are needed to start these reactions
• Some disease where individual doesn’t make a
certain enzyme. Can be fatal. Example ; Tay
Sachs-missing enzyme that breaks down fats
in the brain. These fats accumulate and cause
death by age 5.
NUCLEIC ACIDS
• Building block of DNA and RNA-transmit
genetic information.
• Made of Monomers called nucleotides put
together in a dehydration synthesis reaction.
• 3 Parts: Sugar phosphate and base
Nucleotide structure
Phosphate
Base
Sugar
Nucleotide
• 5 carbon sugar
DNA has deoxyribose
RNA has ribose
• Phosphate group
• Nitrogenous base(Adenine-Thymine)
(Guanine –Cytosine)
(Uracil replaces thymine in
RNA)
DNA-double stranded,RNA single
RNA
• RNA- template for making proteins