Download Atoms

Chapter 2
Organic
◦ Study the carbon compounds
◦ Applied to the living process
Inorganic
◦ The chemistry of all substances but not the carbon
compounds
◦ Applied to non-living process
Atoms
 Smallest particle of an element
 Basic building blocks of all matter.
 They contain protons, neutrons, and electrons.
Nucleus: is the center of the atom, contains protons
and neutrons.
Proton: Positively charged
Neutron: Neutral charge (no charge)
Electron: Negatively charged. They are in constant
motion in the space surrounding the nucleus.
Element
A pure substance,
made of only one kind
of atom.
EX: C, H, O, N
*Carbon, *Hydrogen,
*Oxygen and *Nitrogen.
These four elements
make up 99% of living
things.
They are the most
abundant
• Most abundant compound in
human body is water (H2O).
Compound
◦ Made up of chemically combined elements
EX: NaCl (sodium chloride) & H2O (water)
Molecule
◦ Type of a compound
◦ Elements are held together by a COVALENT BOND
◦ EX: Water = H2O
Isotopes
◦ Atoms of same element that differ in the number of
neutrons
◦ EX: Carbon 12, Carbon 13, Carbon 14 – all have 6
protons, but C12 has 6 n, C13 has 7 n, C14 has 8 n

Take out a separate sheet of paper.

Fold both the left and right edges in towards the
middle of the page so you have 2 flaps.

Divide these flaps into 9 equals sections with a
ruler and a pencil.

Use scissors to cut this flaps.

On the front of the flap, write the following atomic
symbols and vocabulary words:
◦ C, H, O, P, K, I, N, S, Ca, Fe, Mg, Na, Cl
◦ Element, compound, isotope, molecule, atom


On the inner flap, write the corresponding atomic
name of the element or definition of the vocabulary
word.
When finished quiz yourself 2 times, using your
Study Book. Then quiz your shoulder partner.
How & Why Atoms Combine
• Atoms combine with other atoms
when conditions are right
• When atoms combine, they become
more stable
• For most elements, an atom
becomes stable when its outer shell
has 8 e- (H is stable at 2 e-)
Molecular formula:
The symbols and numbers of each type of
atom/element found in that molecule.
Organic Molecules: Contain Carbon (C)
Examples: CO2 C6H12O6
Chemical Equation:
Equations of molecules involved in a chemical
reaction (REACTANTS) along with what they form
(PRODUCTS) from the reaction.
Examples of Chemical Reactions:
1)Photosynthesis
(REACTANTS)
6CO2 + 12 H2O
light
chlorophyll
(PRODUCTS)
C6H12O6 + 6O2 + 6H2O
2) Respiration
 Energy is released from carbohydrates in the
mitochondria (found inside cells)
(REACTANTS)
C6H12O6 + 6O2
(PRODUCTS)
6CO2 + 6H2O + ATP
(energy)
 Aerobic respiration: Uses oxygen and
carbohydrates to produce energy. Carbon
dioxide and water are given off as waste
products.
 Anaerobic respiration: Uses carbohydrates to
produce energy without oxygen. The waste
products of this type of reaction vary. The
following are examples of anaerobic respiration.
Glucose
Glucose
lactic acid + Energy
ethyl alcohol + carbon dioxide
About 60-90 percent of an organism is water
Water is used in most reactions in the body.
Water is called the universal solvent.
Polarity
Water is a molecule with positive and negative
charges at either end, which allows it to bond with
adjacent water molecules.
The positively charged hydrogen attracts to the
negatively charged oxygen end by a hydrogen
bond.
Cohesion: attraction between molecules of the
same substance.
Adhesion: attraction between molecules of
different substances.
Surface tension is the cohesion of water
molecules at the surface of a body of water. All
the water molecules are “holding” each other
together or creating surface tension.
Capillary action however, is related to the
adhesive properties of water.
A giant molecule of living matter formed by the
joining of smaller molecules. Carbohydrates, fats,
proteins and nucleic acids are examples of
macromolecules.
Monomers : a subunit that serves as the building
block of polymer (links)
Polymers: a large molecule consisting of many
identical or similar monomers linked
together. (chain)
Carbohydrates (58% diet)
Starches - contain carbon, hydrogen and oxygen
atoms and break down into sugars which are readily
available energy sources. They are molecules found in cell
walls which gives them support.
Lipids (30% diet)
Fats and oils - contain carbon, hydrogen, and oxygen
atoms and break down into the fatty acids and are for
stored energy sources. They are what cell membranes
are made of.
Glycerol
Proteins (12 % diet)
Meats - contain carbon, hydrogen, oxygen, and nitrogen
atoms and break down into amino acids which are
important for regulating chemical reactions that occur in
living things. These are building materials of all cell parts.
Some proteins control the rate of reactions and regulate
cell processes. Some are used to form bones and
muscles. Others transport substances into or out of cells
or help to fight disease.
Nucleic Acids
Are macromolecules containing hydrogen,
oxygen, nitrogen, carbon and phosphorus.
They are made from individual nucleotides.
Nucleotides contain three parts:
a sugar
a phosphate group
a nitrogenous base
DNA – deoxyribonucleic acid:
It is the genetic material that organisms inherit
from their parents
It is copied and passed along from one generation
of cells to the next.
It stores information for the synthesis of proteins.
RNA – ribonucleic acid:
A copy of DNA that transmits
messages to the cell for protein
synthesis.
Enzymes: are proteins that make the reaction
happen faster because they reduce the
activation energy.
In enzymatic reactions, the molecules at the
beginning of the process are called
substrates, and the enzymes convert them
into different molecules.