Chemicals of Life A Unit on Biochemistry

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Chemicals of Life A Unit on Biochemistry
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Review of terms
Atoms Basic building block of matter.
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Composition of an atom
Made up of three subatomic particles Protons
in the nucleus Neutrons neutral
in the nucleus Electrons ---
electron shell
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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
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Molecules/compounds Two or more atoms bonded
together.
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Most common compoundsin a living organism
Carbohydrates Lipids Proteins Nucleic Acids Water
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C, H, N, O, P, S -These six elements make up
almost all of the cells, tissues and organs of
all living organism . -These six elements and
the compounds they form must be recycled
continuously through our biosphere.
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Global Biogeochemical Cycles
Bio living/biotic factors geo Geological/nonlivi
ng/abiotic factors
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All living organisms require a variety of
nutrients
Examples Carbon dioxide and water are needed
for Photosynthesis Sugar, Oxygen and water are
need for cellular respiration.
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Two types of compounds

• Inorganic compounds
• Do not contain carbon
• Can not be decomposed
• Can be recycled
• Examples
• Sand, glass, styrofoam
• Soil, rocks, metals and
• water

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• Organic Compounds
• Contain carbon
• Are decomposed or broken down and whose nutrients
  are returned to the biosphere.
• Examples
• Anything living or once living
• Dead plants and animals
• Proteins, lipids, carbs and
• nucleic acids

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Inorganic Compounds found in all living organisms
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WATER
-is classified as being inorganic
because.. -does not contain carbon -can not be
decomposed -must be recycled through the
environment through a
biogeochemical cycle known as the
water cycle or hydrological cycle.
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Water or Hydrologic Cycle
Water covers most of our planet. It can be
found in oceans, lakes, and ponds, and in the
ground itself. The water cycle has no beginning
or end.
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• The water cycle collects, purifies and
  distributes the earths supply of water.
• Important terms
• Evaporation
• to change from a liquid into a gas or vapor
• Condensation
• to change from a gas into a liquid
• Precipitation
• rain, snow ,sleet, etc.
• Transpiration
• release of water out of a plant.

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Runoff Rainfall not absorbed by the
soil. Aquifer underground bed or layer
yielding ground water for wells and
springs Groundwater the water beneath the
surface of the ground, consisting largely of
surface water that has seeped down, the source of
water in springs and wells.
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Water or Hydrological Cycle
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Water as a molecule
What do you already know about this important
life sustaining molecule?
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Water H2O
1. Made up of two hydrogen atoms bonded to one
oxygen atom.
2. Atoms bond to form an angular molecule
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3. Water is classified as a polar molecule.
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Polar because like the Earth or a bar magnet it
has a partial positive and a partial negative end.

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One of the most important rules in biology is
that
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Opposites attract
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Therefore, one molecule of waters positive end
is attracted to another molecule of waters
negative end giving water many unique properties.
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Waters unique characteristics
-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 Earths surface -6. Makes up
70 to 80 of a living organism
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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 )
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PHASE DIAGRAM OF WATER
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Phase Change Diagram of Water
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UNIQUE PROPERTIES OF WATER LAB
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Results of the Unique Characteristics of Water
Lab
Experiment 1 What is density? -mass /
volume Density of water? 10g / 10 ml 1
g/ml
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Experiment 2
Water Alcohol
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Why did this occur?
Density Mass/Volume
Water in its solid form is less dense than its
liquid form. But why?
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Water expands when frozen.
Again, WHY ? When frozen, the water molecules
slow down and due to their polarity they will
line themselves up to end thus taking up more
volume and lowering its density.
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-
.
.
O H H
H

H
-
O
H
O
O
H
H
H

Liquid
Solid
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Experiment 3
What is cohesion? -waters attraction to other
water molecules
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Cohesion the attraction between like
molecules. (one water molecule to another
water molecule. - Due to the fact that water is
a polar molecule and opposites attract.
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Experiment 4
What is adhesion? -waters attraction to other
types of molecules (like the paper)
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What is surface tension? A property of liquid
surfaces that causes the surface layer to behave
like a thin elastic 'skin'. Molecules in a
liquid have attractive forces that hold them
together. Molecules on the surface are
attracted to molecules from all sides and below,
but not from above. ...
Experiment 5
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Experiment 6
Why does this occur?
Adhesion is the tendency of certain dissimilar
molecules to cling together due to attractive
forces. Water forms a concaved meniscus. The
water molecules are attracted to the sides of the
glass container.
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Adhesion and cohesion are the two properties that
allows water to move up a plant against the pull
of gravity.
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Experiment 7
Demo of salt dissolving In water.
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Dissolves The molecules of one substance are
picked up and evenly distributed and surrounded
by another type of molecule.
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Experiment 8
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Mixtures
- 2 or more substances combined but not
chemically. -each substance retains its own
properties. -each substance can be separated
from the other.
Examples???????
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Due to its polarity, water is excellent at making
mixtures
- Suspensions - Solutions
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Suspensions
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.
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Blood is a suspension
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Solutions
One substance dissolves into another
substance. Examples Kool aid Salt water
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Cytoplasm is a solution
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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)
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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.
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Aqueous solution water is the solvent Saline
solution salt is the solute Tincture
Alcohol is the solvent
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Types of water solutions
Acids, Bases and Neutral
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Acids A substance that release H ions when
dissolved in water.
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• 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

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Acidic Solutions
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Base A substance that release -OH ions when
dissolved in water.

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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
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Basic Solution
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Neutral
A substance that release no H or OH ions when
dissolved in water
A substance that releases and equal amount of
both the H and the OH ions and they cancel
each other out.
OR
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Neutral Solution
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pH Scale
-measures the strength and weaknesses of an acid
(H) and of bases (OH-) -based on a scale of
0 to 14
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pH scale
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pH and common substances
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Neutralization Reaction
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
Strong neutral neutral acid
base
no H or OH H OH
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Buffer
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.
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Lab Using Acid-Base Indicators
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Indicator Test
-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.
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pH paper
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Litmus Paper -Two types of litmus
paper. -RED and BLUE
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Litmus Paper
Red Litmus Paper - stays red when H
ions are present. -turns blue when
OH- Ions are present.
Blue Litmus Paper - turns red when H
ions are present. -stays blue when OH-
Ions are present.
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Item Color Change Color Change Result of Test
Does the RED litmus paper change to blue? Does the BLUE litmus paper change to red? acid, base or neutral
Benedicts solution yes no yes no
2. Acetamine yes no yes no

3. Salt water yes no yes no