Transcript Chemicals of Life

The study
of the
different
types of
chemicals
found that
make up all
living
organisms
Atoms:
Basic building block of
matter.
Made up of three subatomic particles:
Protons
+
in the nucleus
Neutrons
neutral
in the nucleus
Electrons
--electron shell
Elements:
Substance made up of all
one type of atom.
Six most common elements
found in living organisms:
C, H, N, O, P, S
hyperlink
Molecules/compounds:
Two or more atoms bonded
together.
Molecules/compounds:
-Two or more atoms bonded together to
create a new substance with new
properties.
Example:
Sodium
Table Salt
+
-silvery white solid
-explosive in water
Chlorine
= Sodium Chloride
-green gas
-poisonous
-white solid
-not explosive
-not poisonous
Carbohydrates
Lipids
Proteins
Nucleic Acids
Water
Inorganic compounds:
Do not contain carbon
Can not be decomposed
Must be recycled
Examples:
Sand, glass, styrofoam
Soil, rocks, metals and
water
Organic Compounds:
Contain carbon
Are decomposed or broken down
Examples:
Anything living or once living
Dead plants and animals
Proteins, lipids, carbs and
nucleic acids
1. Made up of two
hydrogen atoms bonded
to one oxygen atom.
2. Atoms
bond to form
an angular
molecule
3. Water is classified as a
polar molecule.
+
Polar because
like the Earth or
a bar magnet it
has a partial
positive and a
partial negative
end.
One of the most important
rules in biology is that:
Opposites attract:
Therefore, one molecule of water’s
positive end is attracted to another
molecule of water’s negative end
giving water many unique
properties.
-
+
-
+
+
-
+
Temporary, weak
hydrogen bonds
form between the
two water
molecules
“holding” the two
molecules
together
-1. Is an inorganic molecule
-Contains no carbon
-2. Made up of two hydrogen atoms
and one oxygen
3. -forms an angular molecule
4. - Is a POLAR MOLECULE
-has a + and a – end
-5. Covers 75% of the Earth’s surface
-6. Makes up 70% to 80% of a living
organism
+
7. -Occurs in three phases
-Solid
-molecules have a small
amount of energy
-a little movement (just vibrating)
-Liquid
-molecules gain some energy
and some movement
-Gas
-molecules gain a lot of energy
and a lot of rapid movement (enough
to escape the surface )
PHASE DIAGRAM OF WATER
Leave blank until
lecture tomorrow
8. Water displays cohesion.
Co =
to work together
Hesion or hesive (think tape) =
to stick together
Cohesion is:
the attraction between like
molecules. (one water molecule to
another water molecule.
- This occurs due to the fact that water is
a polar molecule and opposites attract.
9. Water displays adhesion.
What is adhesion?
-waters attraction to
other types of molecules
(like waters attraction the
paper during a plant
pigment chromatography
lab)
Adhesion is the tendency of
certain dissimilar molecules to
cling together due to attractive
forces.
The water molecules are
attracted to the ‘sides’ of the
graduated cylinder causing the
water to rise up on the sides
Water forms a concaved
meniscus.
The water molecules are
attracted to the sides of the
glass container.
Why does this occur?
When frozen, the water molecules slow
down their movement and due to their
polarity they will line themselves up
+ end to – end thus taking up more
room and lowering its density.
Density is :
Mass/volume
Liquid:
1g/1cm3 = density of 1.0
Solid:
1g / 1.2 cm3 = density of .83
Solid ice with .83 density will
float in liquid water with a 1.0
density
Liquid: water
molecules have more
energy/more
movement thus they
are constantly moving
, regardless of the +
and – charges, they
take up less volume
Solid: molecules
are only vibrating,
they arrange
themselves + end to
– end taking up
more volume.
.
O
H
+
H
H
H
-
H
O
H
+
O
H
Occupies more volume
Solid
O
H
Liquid
Occupies less
volume
11. Water is known as the UNIVERSAL SOLVENT
It dissolves
more
substances
on Earth than
any other
substance
To dissolves means the molecules of
one substance are picked up and
evenly distributed and surrounded
by another type of molecule.
Demo of salt
dissolving
In water.
- 2 or more substances combined
but not chemically.
-each substance retains it’s own
properties.
-each substance can be separated
from the other.
Examples???????
Salt water, kool aid, trail mix
- Suspensions
- Solutions
Example: Oil and water
A substance is
mixed with water
and the 2
substances
separate.
The less dense
substance is
“suspended
above” the more
dense substance.
This happens
because water is
polar and oil is
NONPOLAR (oil
has no + or –
ends)
Red blood cells, white blood cells
and platelets are float around in
the liquid plasma
One substance dissolves into another
substance.
Examples:
Kool aid
Salt water
All of the digested food molecules from the food we
eat and all of the Oxygen molecules from the air we
breathe are dissolved in the liquid component of our
cell’s blood.
Likes dissolve likes
SO:
Polar substances dissolve other polar substances
Polar water will dissolve salt because salt is polar
Nonpolar substances dissolve other non polar substances
Nonpolar oil will dissolve in gas because gas is non polar
Parts of a solution:
Solvent:
Substance doing the
dissolving. (water)
Solute:
Substance being dissolved.
(salt)
Solution:
Created when the solute
DISSOLVES in the solvent.
(salt water)
Water is known as the Universal Solvent.
-dissolves more substances than any other
solvent including all items that need to be
dissolved in living organisms.
Aqueous solution:
water is the solvent
Saline solution:
salt is the solute
Tincture:
Alcohol is the solvent
1.Acids
2.Bases
3.Neutral
HCl / Hydrogen chloride
dissociates into H+ ions and Cl- ions when placed in water
+
-

HCl is Hydrogen Chloride
› H is +1 and Cl is – 1 therefore it is neutral
› Not dangerous to us and our tissues
› When HCl is dissolved into water, the H and
Cl ions separate.

HCl is now known as Hydrochloric Acid
› It is now very dangerous to us and our tissues
HCl / Hydrogen chloride
dissociates into H+ ions and Cl- ions when placed in water
Opposites attract so
the + H is attracted to
the – end of water
and
Cl-
+
-
H+
-Cl is attracted to the
positive end of water
Free H+ ions are
present now so it is
now an ACID
NaOH/Sodium hydroxide
dissociates into Na+ ions and OH- ions when placed in water
NaOH is Sodium Hydroxide
Na is +1 and OH is – 1 therefore it is neutral
Not dangerous to us
When NaOH is dissolved into water, the Na and
OH ions separate.
NaOH, sodium hydroxide is now very
dangerous to us and our tissues
NaOH/Sodium hydroxide
dissociates into Na+ ions and OH- ions when placed in water
Opposites attract so
the + Na is attracted
to the – end of water
and
OH-
+
Na+
-OH is attracted to the
positive end of water
Free OH- ions are
present now so it is
now an BASE
A substance that release no +H
or –OH ions when dissolved in
water
OR
A substance that releases and
equal amount of both the +H
and the – OH ions and they
cancel each other out.
NaCl /sodium chloride
dissociates into +Na and –Cl ions
Cl-
+
Na+
There is NO +H or –OH ions so
therefore it is NOT an acid or a
base so it is NEUTRAL
-measures the strength and
weaknesses of an acid (%H+) and
of bases (%OH-)
-based on a scale of 0 to 14
pH and common substances:
When an acid and a base of equal
strength are mixed and cancel
each other out creating a neutral
substance.
HCl + NaOH ---- NaCl + HOH
Strong
acid
Strong
base
neutral
no H or OH
neutral
H = OH
A substance which guards
against shifts in the pH level.
Our blood is an example of a buffer.
Blood uses extra H+ and OH- ions
substances to help resist pH changes in
our body.
-special chemicals that can show
whether a substance is an acid, a base or
is neutral.
-Two type of indicators:
-pH paper: Used to determine the
strength or weakness of an acid or a
base.
2. Litmus Paper:
-Two types of litmus paper.
-RED
and
BLUE