Transcript CHEMICAL COMPOUNDS OF LIFE

• Living and nonliving things
are all made of elements.
• It is the way that atoms
combine that give every
element a different
characteristic.
• Of the naturally occurring
elements on earth, only 25
are essential to living
organisms.
• The elements Sulfur,
Phosphorus, Oxygen,
Nitrogen, Carbon, and
Hydrogen (SPONCH) are the
main components of living
matter.
• Atoms are the building blocks
of every element and all
matter.
ATOMIC STRUCTURE
• The center of an atom is called
the nucleus.
• Inside the nucleus are positively
charged particles called
protons.
• There are also particles with no
charge, called neutrons.
• Outside the nucleus are
negatively charged particles
called electrons.
•Each atom has equal number of
protons & electrons. No net charge.
ISOTOPES
• Atoms of the same element can
have different numbers of
neutrons.
• These atoms are called isotopes.
• Isotopes are useful to scientists
because they break down & their
radiation is detectable, and can be
used as a diagnostic tools. Ex.
Iodine.
COMPOUNDS AND BONDING
• A compound is a substance
composed of 2 or more different
elements combined.
• When elements combine they
do so to gain stability.
• They can share electrons with
another element or compound
and give away electrons
Covalent Bonds
• When 2 atoms share electrons.
• Most compounds in organisms
covalent bonds.
• A molecule is a group of atoms
held together by covalent
bonds. Ex. H2O
** The electrons travel in the
orbitals of both atoms involved.
Ionic Bonds
• When atoms gain or lose
electrons it becomes an ion.
• The attractive force between 2
ions of opposite charge is
called an ionic bond. Ex. NaCl:
Sodium Chloride
Van der waals forces
• Some atoms have a
stronger attraction for
electrons that others. This
means a higher
electronegativity.
• Even when sharing is equal,
the movement of electrons
can create forces of slight
positive or negative charges.
• When molecules are close
together, a slight attraction
can develop between
oppositely charged regions
of nearby molecules.
• These attractions are called
Van der waals forces.
• They are not as strong as
ionic or covalent bonds but
can hold molecules together
CHEMICAL COMPOUNDS OF
LIFE
•1 Inorganic
compound &
•4 Major organic
compounds found in
living things
WATER
• MOST
IMPORTANT OF
ALL INORGANIC
COMPOUNDS
• 2 Hs & 1O
PROPERTIES:
• COHESION
• ADHESION
• CAPILLARY
ACTION
• Cohesion- An attraction between water
molecules.
• Adhesion- An attraction between water
and a different substance.
• Capillary action is an adhesion between
water and tubes. (ex. Roots in plants)
• Polarity- The oxygen end of a water
molecule is slightly negative because O
has stronger attraction for electrons.
•A molecule that has unequally distributed
charges is called a polar molecule.
Therefore water is considered polar
covalent.
FYI: WATER facts
• RESISTS TEMPERATURE
CHANGES
• EXPANDS WHEN IT FREEZES
• HELD TOGETHER BY H BONDS
DEHYDRATION SYNTHESIS
VS. HYDROLYSIS
• WATER IS
REMOVED WHEN
SYNTHESIZING
(BUILDING) A
MOLECULE
• WATER IS ADDED
TO HYDROLYZE
(BREAK DOWN) A
MOLECULE
Solutions and Suspensions
• A mixture is a material composed of 2
or more elements or compounds that
are physically mixed together but not
chemically combined.
• A type of mixture is a solution.
• In solutions, all the components are
evenly distributed. The solute is the
substance that is solid and the solvent
is the liquid in which the solute
dissolves.
• Some materials don’t dissolve in
water but separate into pieces that
do not settle out.
• Mixtures of water and non dissolved
materials are known as
suspensions.
• Human blood is an example of both
a solution and suspension.
Acids, Bases, and pH
• Water can react to form ions. This
happens to about 1 water molecule
in 550 mllion.
WaterHydrogen+ + Hydroxide-
• Equal numbers of positive and
negative ions are produced which
makes water neutral.
• The pH scale indicates the
concentration of H+ ions. The scale
ranges from 0-14. Pure water has a
pH of 7.
• Each step on the pH scale is a
factor of 10.
• 1.5 Stomach acid; 2.5 lemon juice;
4.5 Acid rain.
• 6 normal rainfall; 8.5 sea water; 10
Soap; 12.5 bleach
• Solutions with a pH below 7 on the
scale are acids. They have higher
concentrations of H+ ions in
solution.
• Solutions with a pH above 7 are
called bases because they have
more OH- ions that H+
• A buffer is a weak acid or base that
can react with strong acids or bases
to cause sudden changes in pH.
Carbon Compounds
•Carbon atoms have 4 free electrons
that can join with electrons from another
atom to form a strong covalent bond.
•Carbon can also bond with other
carbon atoms to form long chains.
These carbon-carbon bonds can be
single, double, or triple covalent bonds.
• Macromolecules are giant
molecules made from thousands of
smaller molecules. Smaller units
called monomers join together to
form polymers. This is called
polymerization.
• The millions of carbon containing
compounds are classified into four
groups of organic compounds:
carbohydrates, lipids, nucleic acids,
and proteins.
CARBOHYDRATES
• Sugars & Starches
• Energy Rich
• Also used for storage
purposes
• Contains C, H, O
• 1:2:1 ratio of C:H:O
• End in –ose
• Ex. Glucose C6H12O6
• Simple sugars are
monosaccharides like glucose,
galactose, and fructose.
• The large carbs formed from
monosaccharides are either
disaccharides or polysaccharides or
starches.
• Animal starch is glycogen and
plants have starch that they store or
use in their structure, like cellulose
LIPIDS
• Contain mostly C, H,
O
• H ratio is larger than
2:1
• 3 Fatty Acids & 1
Glycerol
• Saturated: No
double bonds
• Unsaturated: Double
or Triple Bonds
• Stored energy
NUCLEIC ACIDS
• Contain H,O,N,C,P
• Compose of strands
of nucleotides
• Store and transmit
genetic information.
• 2 kinds:(DNA) and
(RNA)
• RNA contains the
sugar ribose
• DNA contains the
sugar deoxyribose.
PROTEINS
• Contain C, H, O, N,
and possibly S.
• Composed of Amino
Acids: amino group;
carboxyl grp; -R grp
• Ex. Enzymes,
Hormones, Hb,
Insulin, Structural
Proteins
•
1.
2.
3.
4.
Proteins can have up to 4 levels or
organization
The sequence of amino acids in a
protein chain (primary)
The amino acids in a chain twist like a
helix or bend like a pleat (Secondary)
The chain itself is folded (Tertiary) van
der waals and H bonds help to form
globular proteins.
A protein that is assembled from 2 or
more separate chain (Quaternary)
Chemical Reactions
• Take place when bonds are formed
and broken.
REMEMBER: All the chemical
reactions that occur within an
organism are called metabolism.
• Substances that undergo the
reaction are called reactants, and
the substances that form are called
products.
• In chemical equations atoms are
neither created or destroyed, just
rearranged.
• A chemical equation is written so
that the same numbers of atoms of
each element appear on both sides
of the arrow. 2H2 + O22 H20
• Chemical reactions can absorb
energy or release energy.
• The energy released is usually in
the form of heat.
ENZYMES
• The energy that is needed to get
a reaction started is called
activation energy.
• Enzymes decrease activation
energy.
• Complex proteins
• Increase the rates (speed) of
reactions. Biological catalyst.
• End in -ase
• Substances in the
reactions are called
substrates
• LOCK & KEY
(Enzyme-Substrate
Complex) SPECIFIC
• Named after reaction is
catalyzes.
• Ex. To speed up the
breakdown of Maltose
the enzyme Maltase is
used.
Enzyme movie clip
3 Factors that affect enzyme
activity
Temperature
pH
Concentration of enzyme & substrate
Temperature
pH
Concentration of enzyme & substrate