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• Living and nonliving things
are all made of elements.
• It is the way that atoms
combine that give every
element a different
characteristic.
• 98% of the body is made of
only 6 elements
• The 6 elements are:
• Carbon, Hydrogen, Nitrogen,
Oxygen, Phosphorus and
Sulfur (CHNOPS)
• Elements are made of atoms.
Atoms are the building blocks
of all matter.
.
•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 is used to measure the
thyroid's activity.
Molecules and compounds
• 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
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, too much
causes Hypertension
• Ca+2, K+1, Mg+1, P, Fe+2 are
other ions you'll hear about
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.
• Water is the most important
Inorganic Molecule
• Water is most abundant molecule
• 60-70% of the body weight
• Water is polar, has + - ends like a
magnet.
Characteristics of water
• Cohesive, fills vessels
• Absorbs heat for cooling
• Since water is polar, it is a
good solvent- helps facilitate
reactions in the cells.
• NaCl, acids and bases
dissociate in water (break
apart) These are called
Acids, Bases, and pH
• 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.
pH scale
• 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+
Blood has a pH of 7.4
Buffer: is a weak acid or base that
can react to sudden changes in pH.
Acidosis:Blood pH below 7.35
Alkalosis: Blood pH above 7.45
A person usually cannot survive if the
pH drops to 6.9 or rises to 7.8 for
more than a few hours.
Part 2: Organic molecules
•All contain carbon which create the
skeleton for biomolecules (carbs, lipids,
proteins and nucleic acids)
•Carbon can also bond with other
carbon atoms to form long chains.
These carbon-carbon bonds can be
single, double, or triple covalent bonds.
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.
Condensation vs Hydrolysis
Water is taken away to build larger
molecules-->condensation synthesis
Water is added to break apart large
molecules---> Hydrolysis.
• The large carbs formed from
monosaccharides are either
disaccharides (2 monosaccharides)
like maltose or polysaccharides
(glycogen, starch and cellulose)
• Glycogen is stored formed of
glucose in the liver of humans. The
liver releases glucose so that the
blood levels are .1%. If the blood
contains more glucose it spills over
into the urine indicating diabetes
may exist.
• Starch and cellulose are in plants
LIPIDS
•
•
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•
•
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Contain mostly C, H, O
H ratio is larger than 2:1
3 Fatty Acids & 1 Glycerol
Saturated: No double
bonds
Unsaturated: Double
bonds, found in veg. oil
Stored energy
Phospholipids are found in
cell membranes. Polar
head and tails
Steroids are also lipids
PROTEINS
• Hair, nails, muscles,
some act as enzymes
• Contain C, H, O, N,
and possibly S.
• Composed of Amino
Acids by
condensation
synthesis
• 4 shapes
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
•
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)
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.
ATP
Has high energy phosphate
bonds.
Used for synthetic reactions,
nerve impulses, muscle
contractions.
The energy needed to rebuild
ATP comes from glucose
metabolism.
Chemical Reactions
• Take place when bonds are formed
and broken.
REMEMBER: All the chemical
reactions that occur within an
organism are called metabolism.
Enzyme movie clip