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Site of most chemical
reactions in the cell
The Levels of organization
Anything that has mass and takes
up space (volume).
All matter is made up of atoms.
ATOMS
The small units of matter
Made up of Protons, Neutrons, and
Electrons
Atoms are smaller than cells
Pure substances made up of only one
type of atom
-Major 4 elements:
Carbon
Hydrogen
Oxygen
Nitrogen
(C)
(H)
(O)
(N)
COMPOUNDS
• combination of 2 or more elements in
definite proportions
– Ex: water, salt, glucose, carbon dioxide
Inorganic Compounds
Do not contain carbon usually
(exceptions: CO and CO2)
Types:
Water
Salts
Acids
Bases
Organic Compounds
Always contain C and H
Usually have O and N
May contain P and S
Associated with life:
bodies of organisms, remains, waste
Four Types of Organic Compounds
Carbohydrates
Lipids
Proteins
Nucleic Acids
The smallest part of a compound
that has the properties of that
compound.
Example: H2O
Atoms of the same element that bond in
pairs to become stable.
H2
O2
N2
Never found in
nature as single
atoms.
FORMULAS
•
•
•
Chemical symbols and numbers that make
up a compound ("recipe")
Structural Formula – Line drawings of the
compound that shows the elements in
proportion and how they are bonded
Molecular Formula – the ACTUAL
formula for a compound
C6H12O6
THE PROTON
• Fat
(heavy)
+
p
• Positive 
(charge)
• Doesn’t move
(lazy)
THE NEUTRON

°
N
• Fat
(heavy)
• Neutral 
(charge)
• Doesn’t move
(lazy)
THE ELECTRON
• Skinny
(very light)
e
• Negative 
(charge)
• Moves a lot
(runs around)
Review: Subatomic Particles
+
p

°
N
e-
The outermost electrons of an element.
Valence electrons are the most reactive and are
involved in chemical bonding.
http://www.Chemicool Periodic Tablechemicool.com/
• Hold atoms in molecule together
• 3 types of chemical bonds:
– IONIC
– COVALENT
– HYDROGEN
• 1 or more electrons are TRANSFERRED
from one atom to another
• If atom loses an electron: POSITIVE
charge
• If atom gains an electron: NEGATIVE
charge
• These newly charged atoms are now
called IONS
– Example: NaCl (SALT)
• Electrons are SHARED by atoms
• New structures that result are called
MOLECULES
SHARING IS CARING!
Which type of bond? Covalent or ionic?
Which type of bond? Covalent or Ionic?
Valence Electrons
bonding that involves electronegative
attraction between H atoms
1) Universal solvent
2) Medium for chemical reactions
3) Raw material for chemical reactions
4) Transport medium
Penny Activity
• Obtain a penny and a pipette with H2O
• Your goal is to place as many drops of water
on the surface of the penny without spilling
the H2O.
• Place drops on the penny one at a time and
keep track (be honest) of how many you
place on the penny.
• Record your results in your notes.
Penny Activity
• Why were you able to place so many drops
of water on the penny?
• What type of bond might be involved?
• What are adhesion and cohesion?
• Did the side of the penny affect your
results?
Contain C, H, O
Ratio of H and O is 2:1
Most end in “ose”
Building Block = Monosaccharide
Glucose
C6H12O6
Fructose
Galactose
Mono=one
C6H12O6
Same Molecular
Formula
Different
Structural
Formulas
Di=two
Molecules formed by joining two
monosaccharides
Glucose + Glucose
Glucose + Fructose
Glucose + Galactose
Maltose
Sucrose
Lactose
C12H22O11
Poly=many
Long chain of joined monosaccharides
(Sugar Polymer)
Organisms store excess glucose as
polysaccharides
Plants store as STARCH
Animals store as GLYCOGEN
Examples: cellulose, chitin
1) Quick energy source
2) Make cell structures (cell walls)
How are complex carbohydrates
formed and broken down?
Maltose
(Disaccharide)
Process that joins molecules by
removing water
H2O
H
HO
GlucoseMaltose Glucose
Process that breaks down molecules by
H
O
2
adding water.
Fats
Oils
Waxes
Contain C, H, O
Less O then found in Carbohydrate
1 Glycerol
Building Blocks =
&
3 Fatty Acids
1) Reserve energy source (9 calories/gram)
2) Component of cell structures
(example: Cell Membrane)
3) Insulation and Cushioning
Lipids are found in the cell membrane of
cells.
Contains C, H, O, N
Sometimes contains S and P
Building Block = Amino Acids
Amino Acid consists of:
1) Central C atom
2) Carboxyl group
3) Amino group
4) H atom
5) Representative group ®
Amino Acid
R=H
(Glycine)
R = CH3 (Alanine)
What is the R group in this
compound?
AN R GROUP IS ANY
GROUP OF ATOMS – THIS
CHANGES THE
PROPERTIES OF THE
PROTEIN!
________
Peptide Bond
H 2O
What is the name of this process?
Polypeptide
Protein consisting of three or more
amino acids joined together
1) Structural Parts (hair, nails, cartilage)
2) Pigments (blood, skin, eyes)
3) Contractile Material (muscle tissue)
4) Antibodies (protect against infection)
5) Hormones (Chemical messengers)
6) Enzymes (control chemical reactions)
7) Energy Source (4 calories/gram)
Contains C, H, O, N, P
Two Types:
Deoxyribonucleic Acid (DNA)
Ribonucleic Acid (RNA)
DNA – Hereditary Material
RNA – Controls activities and development
of cells
Building Block = Nucleotide
Nucleotide consists of:
1) Five carbon sugar
2) Phosphate group
P
3) Nitrogen base
adenine
thymine (DNA only)
guanine
cytosine
uracil (RNA only)
A
T
G
C
U
A T
G C
G C
T A
C G
A T
A T
T A
G C
C G
C G
G C
DNA
G C
A U
U A
C G
C G
U A
A U
C G
G C
U A
A U
C G
RNA
DNA
RNA
Double Stranded
Single Stranded
Deoxyribose
Ribose
Thymine
Uracil
T
A
P
P
A
T
P
P
C
G
P
P
G
P
C
P
Base Pair Rule
A  T
G  C
ACIDS & BASES
•
Acids: Begin with "H-" (excess of H+
ions: hydrogen)
–
Ex: lemon juice (6), stomach acid (1.5), acid
rain (4.5), normal rain (6)
Facts about Acids
• Acids turn litmus paper RED and usually
taste SOUR.
• You eat acids daily (coffee, vinegar, soda,
spicy foods, etc…)
ACIDS & BASES
• Bases: end with -OH (excess of hydroxide
ions: Oxygen & Hydrogen)
– EX: oven cleaner, bleach, ammonia, sea water,
blood, pure water
Facts about Bases
• Bases turn litmus BLUE.
• Bases usually feel SLIPPERY to touch and
taste BITTER.
Neutralization Reactions
• When an acid reacts with a base to produce
a salt and water.
pH SCALE
• measures degree of
substance alkalinity or
acidity
• Ranges from 0 to 14
• 0 – 5 strong acid
• 6-7 neutral
• 8-14 strong base
Effects of Acid Rain
• The goal of the body is to maintain
HOMEOSTASIS – to do this when pH is
concerned, we add weak acids & bases to
prevent sharp changes in pH.
• These are called BUFFERS
Homeostasis: relatively stable internal environment
a.k.a: dynamic equilibrium
Protein substance …made on ribosomes
Control all chemical reactions in organisms
Not changed by the reaction
Can be used again
Referred to as an “organic catalyst”
Lower activation energy (NRG needed to start Rx)
Substrate: Substance enzymes works on
Dr. David R. Howard, Asst. Prof.
Univ. of Wisconsin La Crosse
Usually ends in “ase”
Name often comes from substrate
Examples:
Maltase
(Maltose  Glucose)
Protease (Breaks down proteins)
Lipase (Breaks down lipids)
Temporary union of the enzyme and
substrate at the “active site”
Active Site:
- Area of an enzyme
- Substrate molecule fits in shape of active
site
- Active sites are specific for substrates
igure 8.16
Substate
Active site
Enzyme
(a)
Enzyme- substrate
complex
Figure 8.16
(b)
Enzymes work on specific substrates
Reason: specific active site on enzyme
Example: Lactase only breaks down Lactose
Maltase only breaks down Maltose
Cellulase only breaks down cellulose
1) Small amounts of enzymes can cause
the reaction of large amounts of substrates
2) Enzymes allow cell reactions to occur at
“normal” temperatures
3) Enzymes work best at specific temperatures
Optimal Temperature is when enzyme
is most effective
Denaturation: Deformation of active site
due to high temperature
4) Enzymes work best at certain pH
Human Examples:
Amylase pH 8
Pepsin pH 2
Trypsin pH 8
5) Rate of an enzyme controlled reaction
depends on the concentration of enzymes
and substrates.
- more enzymes faster the rate of reaction
- maximum rate (enzymes = substrates)
** When there is a fixed amount of enzyme
and an excess of substrate molecules -- the
rate of reaction will increase to a point and
then level off**
6) Some enzymes need coenzymes to
function
Coenzymes:
- are not proteins
- may be part of enzyme molecule or
a separate molecule
- may be altered during E-S Complex,
but return to original form after reaction
- may be vitamin or made from vitamin
7) Most enzymes functions inside cells,
some functions outside
- all enzymes are made by cells
- digestive enzymes function outside cells
Enzymes
(and beyond …)
•
Inhibitors—reduce
the productivity of
enzymes as seen to
the right with
herbicides.
.
.
.
.