Notes: Chapter 3
Section 3-1
Chemistry of life:
Atoms:
Atom: matter that exist in small units
 Center of atom = nucleus
 Neutrons and protons are found in the
nucleus
 Protons have positive charge
 Protons have mass = 1 amu
 Neutrons are neutral = no charge
 Neutrons have mass = 1 amu
 Electrons are found outside the nucleus as
rings (like planets revolving around the sun)
 Electrons have negative charge
 Electrons mass is considered zero
 When atoms are broken energy is released
sometimes in the form of light (ex. Fire
flies)
Elements:
Elements: a piece of matter made up of only one type
of atom. (see hand out)
 Our bodies are made of one element or a
combination of elements
Q: What are the most common elements in your body?
Answer: _________________________________________
_________________________________________________.
Using Periodic Table:
Groups and Periods: used to find elements with instruction
 Groups are columns of periodic table.
 Periods are rows of periodic table
Reading element box:
 Atomic # is the smallest of the two numbers
= # of protons and # of electrons
 Atomic mass is the larger of the two
numbers = number of protons and neutrons.
 Neutron #: subtract atomic number from
atomic mass = neutron #
 Symbol: single capital letter or two
letters(1st letter is a capital and second lower
is case.)
Drawing Bohr’s Model:
Rules: start drawing from center (nucleus) and work your way
out.
Nucleus: place protons and neutrons in nucleus
Atom
with proper amount. Ex. P = 6, n = 6
Orbital: Electrons go in orbitals (rings outside
the nucleus.) AKA..Energy level
Orbital rules:
1st Orbital …Holds 2 electrons max.
2nd Orbital… Holds 8 electrons max.
3rd Orbital… Holds 18 electrons max.
4th Orbital… Holds 32 electrons max.
Compound:
Compound: are a result of atoms of different
elements combining to form new substances.
 Water is an example of a compound it
contain two hydrogen atoms and one
oxygen atom to form one Molecule of
water. (H2O)
 One bucket of water has many molecule s
of water = 1, 000,000 H2O
 Glucose = sugar =compound = C6H12O6
Give another Example of a compound_______________________
_____________________________________________________.
Demonstrate Balloon and salt
Ions:
Ions: an atom with a charge
 Most atoms are neutral = no charge ex.
 Neutral atoms have same amount of electrons and protons
 Ions do not have equal number of protons and electrons =
gain or loss of electrons ex.
 Proton number never changes
 Compounds are formed by this opposite attraction of unlike
charges ex.
Mixtures:
Mixtures: combination of substances can be
mixed together that do not chemically combine.
 Ex. Combining salt and sugar with water. They will
dissolve but will not chemically combine to form a new
substance.
Solution vs Suspension:
Solution: def. A Mixture in which two or more
substance mix together evenly.
 Ex. Dissolve salt in water to make a salt solution.
 Salt is found in sweat, cells are bathed in a salt solution
Suspension: A Mixture in which two or more
substances mix unevenly in a liquid or a gas.
 Ex. Orange juice; the pulp and other large particles
separate and settle.
 Blood is another example in our bodies, RBC’s, WBC’S
and platelets settle to the bottom of blood over time.
Organic Compounds:
Organic Compounds: compounds containing carbon
and hydrogen.
4 typical compounds found in our bodies:
1. Carbohydrates = sugar = glucose
2. Lipids = fat; make steroids
3. Proteins: make enzymes
 Enzymes speed up chemical reactions
4. Nucleic Acids: forms codes (information = recipes)
found in DNA, mitochondria and chloroplasts
Organic Compounds That Make Up Life
Carbohydrates
Lipids
Protein
nucleic acids
Composition
Orgnc
cmpnds made
of crbn, hdgn
and oxgn
Orgnc
cmpnds made
of crbn, hdgn
and oxgn
Orgnc
cmpnds made
of crbn, hdgn,
oxgn and
ntrgn
Orgnc
cmpnds made
of crbn, hdgn,
oxgn, ntrgn
and
phosphrus
Examples
Sugar, starch,
cellulose
Fats, oils and
waxes
enzymes
DNA, RNA
Function
Broken down
to release
energy, energy
aids in cell
function
Contains lots
of stored
energy more
than carbs
Used to build
cell parts
Carries
hereditary
information
Cell
membrane
Location
Cell
membrane
has two layers
Scattered
throughout
cell
membrane
Nucleus and
DNA,
chromosomes
Inorganic Compounds:
Inorganic Compounds: made from elements that do not
contain both carbon and hydrogen.
 Ex. Water (H2O), carbon dioxide CO2, carbon
monoxide CO.
 Our bodies need both inorganic compounds and organic
compounds to live.
Section 3-2
Cell Processes:
Cell transport:
 Materials move in and out of cell(wastes out, nutrients
in).
 Cell membrane is selectively permeable = allows
something in and keeps others out. Ex. A strainer;
water is released while spaghetti stays in.
 Molecules diffuse in and out of cell to reach
equilibrium = homeostasis.
Diffusion: matter (liquid/gases) moving from an area
of high concentration (molecules close together) to
low concentration (molecules far apart).
 During diffusion molecules that are close together are
spreading apart to find equilibrium.
 Diffusion of water = osmosis
 Osmosis allows roots from plants to transport water to
other parts of plant. Ex. Leaves
 Wilting is caused by a lack of water = less osmosis
Equilibrium: is the equal spacing of molecules in a
substance.
 Once equilibrium is met molecules continue to move to
sustain equilibrium.
Types of transport:
1. Passive transport: movement of material across
cell membrane by diffusion.
 Molecules move from a crowded room
to a less crowded room.
2. Active transport: movement of material across
cell membrane by cellular energy
 Molecule transport assisted by protein
found embedded in cell membrane.
 Molecules move from les crowded
room to a more crowded room
Types of Active transport:
a. Endocytosis: engulfing a large
molecule by membrane reaching out
and around. Ex. Big blob.
 Molecules move into cell
with the help of cell energy.
b. Exocytosis: wastes in vacuoles
or proteins packaged by golgi
bodies reach cell membrane and
fuse to release contents out of cell.
3-3 Energy For life
Metabolism: total of all CHEMICAL activities of
an organism that allow it to stay alive, grow and
reproduce.
 Respiration in cells is an example of metabolism =
sugars are broken down in cells and converted to useful
form = ATP (Adenosine Triphosphate) for the body.
Ex. Break down glucose ATP, making proteins =
making enzymes.
Type of Living Things:
1. Producers- organisms that make their own food
= plants/trees/algae
2. Consumers- organisms that cant make their own
food = humans and dogs
Photosynthesis: producers (plants) change light energy into
chemical energy.
 During photosynthesis energy from sunlight is used to
make sugar = glucose = C6H12O6 from carbon dioxide
(CO2) and water (H2O).
Equation: CO2+H2O+light energy  C6H12O6 + 6O2
Reactants
product
 Energy (sugar) that is made is used by plant for other
activities or stored in vacuoles.
 Chlorophyl is green pigment that traps radiant energy
(light energy).
Releasing Energy:
Cellular Respiration:
 Either consumer or producer must release energy from
food to make it useful.
 Both producers and consumers cells break down food in
process called Cellular Respiration
 Cellular respiration needs oxygen to break down
glucose in animal cells
 Cellular respiration takes place in Mitochondria =
metabolism
Equation: C6H12O6+6O26CO2 + 6H2O + Energy
Fermentation: form of respiration in animal cells that
breaks down glucose with out oxygen
 Fermentation takes place when oxygen levels are low
 Us as humans use fermentation when we have been
exercising for long periods of time.
 Lactic acid forms when exercising and causes muscles to be
sore = burning
 Energy is released in the form of heat