Download Chapter 2: The Chemistry of Life

Chapter 2: The Chemistry of Life
2.1 The Nature of Matter
A. Atoms made up of:
Protons
 Found in
nucleus
 Positively
charged
Neutrons
 Found in
nucleus
 Neutral
charge
Electrons
 Negatively
charged
 In motion
surrounding
nucleus
B. Elements – pure substance made up of 1 type of
atom
ACTIVITY: Period Table!!
C. Chemical Compounds - substance formed by the
combination of 2 or more elements
1. Chemical Formula – shows the ratio of
elements
a. Ex: Water H2O (2 Hydrogen, 1 Oxygen)
Salt NaCl (1 Sodium, 1 Chloride)
C6H12O6
D. Types of Chemical Bonds
1. Ionic Bonds – transfer of electrons (e-)
between atoms
a. Ions – positively and negatively charged
atoms due to transfer of electrons
2. Covalent Bonds – electrons are shared
between atoms
a. Molecule – smallest unit of a compound
1) Ex: Water Molecule
2.2 Properties of Water
A. The Water Molecule
1. Polarity – water molecule is polar because
there is an uneven distribution of electrons between
the oxygen and hydrogen atoms
a. O has 8 protons and will attract the
hydrogen’s electrons with a greater pull
1) H will have a slightly positive charge;
O will have a slightly negative charge
2. Hydrogen Bonds - Polar molecules attract
each other, because of the charged regions
a. Cohesion – attraction of molecules of the
same substance
1) Water is extremely cohesive
2) Why water beads on smooth
surfaces
3) Why insects and spiders can walk on
the surface of the water
b. Adhesion – attraction of molecules of
different substances
1) Capillary Action – adhesion between
water molecules and glass molecules cause water to
rise against gravity
a) Meniscus in graduated cylinders
b) Plant roots draw water out to
stems
3. Acids, Bases and pH
a. The pH Scale – indicated the
concentration of H+ ions in solution
pg 42 drawing
1) Pure water has a pH of 7
2) pH below 7 is acidic, because the
solution has more H+ ions then OH- ions
3) pH above 7 is basic, because the
solution has less H+ ions then OH- ions
pH Lab!
2.3 Carbon Compound
A. The Chemistry of Carbon
1. Organic Chemistry – study of all compounds
containing bonds between C atoms
a. C -single, double and triple bonds
1) Form chains and rings
2) Large complex structures
B. Macromolecules – “giant molecules”
1. Polymerization – large compounds are put
together by small units
a. Monomers – small units
b. Polymers – larger compounds
C. Organic Compounds Found in Living Things
1. Carbohydrates – made up of C, H, O
a. Main source of energy
1) Break down of sugars supplies
energy
(a) Glycogen – Stored in muscles,
supplies energy for movement
(b) Cellulose – plant starch, wood
and paper
2. Lipids – made of C, H
a. Store energy; Fats, oils, waxes, and
steroids
b. Fatty acids
1) Saturated – found in animal fats and
processed foods
2) Unsaturated – found in corn,
sunflower and soybean oil
(1) liquid at room temp
3. Nucleic Acids – made of C, H, O, P, N
a. Nucleotides – 5-carbon sugar, phosphate
group, and
nitrogenous base
b. Nucleic Acid – nucleotides joined by
covalent bonds
1) Store and transmit genetic info
a) RNA – Ribonucleic Acid
b) DNA – Deoxyribonucleic Acid
4. Proteins – made of C, H, O, N
a. Amino Acids –
1) 20 different amino acids
2) all amino acids can join together
b. Proteins – chains of amino acids, control
rate of reactions and
cell processes
1) instruction of building chain found in
DNA
2) some proteins transport material in
and out of cell, help
fight disease, form muscle and
bone
2.4 Chemical Reactions A. Chemical Reactions – process that changes one
set of chemicals into another
1. Reactants – compounds that enter into the
reaction
2. Products – compounds produced by the
reaction
3. Always involves breaking of chemical bonds