Chapter 2
The Chemistry of Life
2-1 The Nature of Matter
Let's see what you know!!!
C6H12O6 + 6O2 →
CO2 +
H2O
1. Write everything you know about this equation.
2. Name the compounds.
3. How many atoms of each element?
4. Balance this equation.
Answers
1. vary- formula for cellular respiration
2. Glucose, Oxygen, Carbon Dioxide, Water
3. 7-Carbon, 14-Hydrogen, 21-Oxygen
4.
C6H12O6 + 6O2 → 6CO2 + 6H2O
Key Concepts
1. What three subatomic particles make up atoms?
2. How are all of the isotopes of an element similar?
3. What are the two main types of chemical bonds?
Quote on page 35 - If the first task of an architect is to understand building
materials, then the first job of a biologist is to understand the chemistry of life.
Chemistry
study of the composition and properties of substances
Matter
anything that occupies space and has mass
everything in the Universe is made of matter
solid, liquid, gas, plasma
Atom
basic unit of matter
"unable to cut"
very small
about 100 million atoms make up about 1 cm
or about the width of your little finger
inside atom are subatomic particles
Nucleus
central portion of atom that contains the protons and
neutrons that are held together by Strong Forces
Subatomic Particles
Protons
positively charged particles
located inside nucleus
represents the atomic number
Oxygen has 8 protons, so atomic number = 8
Neutrons
neutrally charged particles
located inside nucleus
Sum of neutrons and protons = atomic mass
Electrons
negatively charged particles
located outside the nucleus - electron cloud
constant motion around nucleus
same number of electrons as protons
atom wants to be neutral
Element
contains only one kind of atom
only about 24 elements are found in living organisms
Carbon
Calcium
Chlorine
Hydrogen
Iron
Magnesium
Oxygen
Phosphorus
Sulphur
Appendix H - The Periodic Table
http://www.chem4kids.com/files/atom_structure.html
Fluorine
Nitrogen
Silica
Isotope
elements that differ in the number of neutrons
but will share chemical properties because they
the same number of electrons/protons
they will have the same number of electrons/protons
or they become a different element
Look at example on page 36.
Carbon -12, Carbon -13, Carbon 14
Can an isotope of an element occur if the number of protons change?
Radioactive Isotopes
radioactive
unstable so they break down
Compound
when two or more elements combine
forms a chemical formula
H20 CO2
What information is contained in a chemical formula?
The types of elements that are in the compounds and
the ratio in which atoms of those elements combine.
Chemical Bonds
elements in compounds are held together by chemical bonds
Ionic Bond
formed when electrons are moved from one atom to another
formed when a nonmetal bonds with a metal
Look at periodic table
https://www.youtube.com/watch?v=Qf07-8Jhhpc
Covalent Bond
formed when electrons are shared between elements
molecule
smallest unit of compounds
https://www.youtube.com/watch?v=UR4eG60jjQQ
Van der Waals Forces
the attraction of the particles when elements are close
together
not as strong as Ionic or Covalent Bonds