Download Acidic

Class Notes
Honors Biology
“LIFE
CHEMISTRY”
Water
•The most important
property of the water
molecule is that it is
charged on each end
W
AT
ER
-
H
O
H
+
M
O
LE
C
U
LE
Mixture:
• Substance composed of two or
more elements or compounds
that are mixed together but not
chemically combined
• ex - salt and pepper / sugar
and sand
Suspensions:
• Mixture of water and a nondissolved material
• Material does not dissolve and
does not settle in the liquid
• It remains ‘suspended’
• Ex - Blood, Oil and Water, Gravy
Solution:
A substance dissolves
in another
Ex - Sugar in water
Solvent:
•The substance that
does the dissolving
•Ex - The water
Solute:
•The substance that
is dissolved
•Ex - The sugar
Acids
and
Bases
Acids:
• Compounds that release
hydrogen ions ( H + ) into
solution
• Ex - Hydrochloric acid (HCl)
• HCl ---> H+ + Cl -
Acids tend to have the
following characteristics:
• ionize in water to generate
hydrogen ions [H+]
• turn litmus paper RED
• induce a sour taste
(e.g.
lemon)
• have a pH less than 7
Bases:
• Compounds that release
hydroxide ions (OH - ) into
solution
• Ex - Sodium Hydroxide
(NaOH)
+
• NaOH ---> Na
+ OH
Bases tend to have the
following characteristics:
• ionize in water to generate
hydroxide ions [OH-]
• turn litmus paper BLUE
• induce a bitter taste
• feel slimy
• Have a pH more than 7
Look at each of the
following product
and see if you can
guess if it is an
ACID or a BASE....
ACID
OR
BASE
????
?
ACID
OR
BASE
????
?
ACID
OR
BASE
????
?
ACID OR BASE
?????
ACID
OR
BASE
?????
ACID OR BASE
?????
pH Scale:
• A measurement system
that indicates the relative
concentrations of
hydrogen ions [H+] and
hydroxide ions [OH-]
• pH Scale runs from 0 to 14
• A difference of 1 on the scale is
actually a difference of 10 times the
relative strength of the acids or
bases:
• ‘0’ means 100 = 1
• ‘1’ means 101 = 10
• ’2’ means 102 = 100
• ‘3’ means 103 = 1000
etc.....
Increasingly Basic
Page 66 in your
book
Neutral
Increasingly Acidic
pH scale
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Lye
Household Bleach
Oven Cleaner
Household Ammonia
Soap
Baking Soda
Sea Water
Human Blood
Tears
Water
Saliva
Urine
Normal rainwater
Shampoo
Tomatoes
Vinegar/Cola
Lemon Juice
Stomach Acid
• Acidic = 0 to 6 = H+ ion concentration (0
is highly acidic)
• Neutral = 7 = Equal conc. of H+ and OH- ions
(water)
• Basic = 8 to 14 = OH- ion concentration (14
is highly basic)
• Neutralize an acid by adding a base
• Neutralize a base by adding an acid
•
+
H
+
OH
-----> H2O
Inorganic vs Organic Compounds
•Organic means the
compound contains
Carbon
• Inorganic means it does
not contain Carbon
Carbon:
• Living things contain carbon
• Carbon is special because of the
strong and stable bonds that it
can form
• Carbon has 4 electrons in its
second energy level
• This means that it can form 4
single covalent bonds
Polymerization:
• Large compounds (polymers)
formed from smaller ones
(monomers)
• Macromolecules: are giant
polymers
4 Basic Molecules of Life:
•
•
•
•
CARBOHYDRATES
LIPIDS
PROTEINS
NUCLEIC ACIDS
CARBOHYDRATES :
(Sugars and Starches)
 Contain energy stored in the
bonds that make the molecules
 When the bonds are broken the
energy is released
Glucose is the basic energy
source for organisms
3 Kinds of Carbohydrates:
 MONOSACCHARIDES
 DISACCHARIDES
 POLYSACCHARIDES
MONOSACCHARIDES :
 MONO means “ONE”
 3 KINDS:
GLUCOSE (sugar in green plants)
FRUCTOSE (sugar in fruit)
GALACTOSE (sugar in milk)
Formula is
C6H12O6
They
differ in the arrangement of atoms
DISACCHARIDES :
 DI- means “TWO”
 3 KINDS:
 SUCROSE - Table Sugar
(glucose + fructose)
 LACTOSE - Milk Sugar
(glucose + galactose)
 MALTOSE - Malt Sugar
(glucose + glucose)
POLYSACCHARIDES :
 -POLY- means “MANY”
 Made of long strings of
simple sugar molecules
POLYSACCHARIDES :
 3 KINDS
- STARCH
- CELLULOSE
- GLYCOGEN
STARCH
 A Large Storage
Molecule in Plants
 Found in potatoes,
bread, pasta, etc.
CELLULOSE
 A large molecule used as
Structure in Plants (Fiber)
 Fiber is Important in Human Diet
Cannot be digested in Humans Cleans your Intestines
GLYCOGEN
 Large storage molecule
in animals
 Broken down for energy
as you need it
Dehydration Synthesis:
Dehydration = loss of water
Synthesis = putting together
 This reaction forms complex
carbohydrates by combining
two or more monosaccharides
 Each time a bond is formed, a
molecule of water is removed
(dehydration)
Hydrolysis
:
 Reaction occurs when
polysaccharides are split apart
to form monosaccharides
 Means “water splitting”
 Reverse reaction of
dehydration synthesis
LIPIDS :
• Organic compounds that are waxy or
oily
• Made of Fatty Acids + Glycerol
• Used to store energy, form
biological membranes, used as
chemical messengers
• FATS / OILS / WAXES /
PHOSPHOLIPIDS / STEROLS
FATS / OILS / WAXES
:
• Fats and waxes are solid at room
temperature, oils are liquid
• Plants and animals use lipids to store
energy
• When broken down, lipids produce
more energy than carbohydrates
• Fats can be Saturated or
Unsaturated or Polyunsaturated
• Saturated - Has every carbon
joined by a single bond, it
contains the maximum number of
hydrogen atoms
• Unsaturated - contains a pair of
carbons that is joined by a double
bond
• Polyunsaturated - contains
several double bonds
• Polyunsaturated fats are liquid at
room temperature and are used
as cooking oils. Ex - sesame oil,
peanut oil, corn oil, olive oil
• Replacing saturated fats in your
diet with polyunsaturated fats may
help prevent heart disease
PHOSPHOLIPIDS
:
• Contains parts that dissolve well in
water and parts that don’t dissolve
well in water
• Liposomes - spontaneous forming
balloon-like structures with a double
layer of lipid molecules (“lipid
bilayer”)
• Lipid Bilayers form Cell Membranes
STEROL LIPIDS
:
• Important in building cells and
carrying messages from one part of
the body to another (hormones)
• Cholesterol - common sterol important in many animal cells - if
excessive in diet, it is a risk factor in
heart disease
PROTEINS :
 FUNCTIONS of Proteins include:
Movement, Structure, Transport,
Biochemical Control, Storage,
Regulation, Defense
 Are Polymers of more than 20
different AMINO ACIDS
 Peptide Bond: Type of covalent
bond that joins two amino acids
Catalyst:
 Any substance that speeds up the
rate of chemical reactions without
being changed by the reaction
They work by lowering the “startup” energy of a reaction
 Enzymes are the catalysts in living
organisms
Enzymes:
 are a special group of proteins
that speed up the chemical
reactions that are necessary for
the ordinary activities of life
 simple cell may contain over
2000 different enzymes, each a
catalyst for a different reaction
 Substrates: are the
substances that are
affected by an enzyme
 Active Site: the region that
substrates bind to on an
enzyme
(like a “Lock
and Key”)
Enzyme Functions:
 Regulating chemical pathways,
synthesizing materials needed by
cells, releasing energy, and
transferring information
 Involved in digestion, respiration,
reproduction, vision, movement,
thought, and even making other
enzymes
NUCLEIC ACIDS :
 Polymers of Nucleotides
 2 Kinds :
RNA Ribonucleic Acid
- Makes Proteins
DNA
Deoxyribonucleic Acid Store and Transmit Genetic
Information
Page 66 in your
book
Increasingly Basic
pH scale
Copy this
scale for your
notes
Increasingly Acidic
Neutral
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Lye
Household Bleach
Oven Cleaner
Stomach Acid
Household Ammonia
Soap
Baking Soda
Sea Water
Human Blood
Tears
Water
Saliva
Urine
Normal rainwater
Shampoo
Tomatoes
Vinegar/Cola
Lemon Juice
Stomach Acid