1. THE SCOPE OF LIFE The Properties of Life
a Order
b Regulation
c Growth and development
d Energy utilization

2. THE SCOPE OF LIFE The Properties of Life
f Reproduction
e Response to the environment
g Evolution

3. Life at Its Many Levels
Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.
Biosphere
Ecosystems
Communities
Populations
Organisms
Organ Systems
and Organs
Tissues
Cells
Organelles
Molecules and Atoms
Atom
Nucleus

4. Life in Its Diverse Forms
Diversity is the hallmark of life.
The diversity of known life includes 1.8 million species.
Estimates of the total diversity range from 10 million to over 100 million species.

5. Grouping Species Biodiversity can be beautiful but overwhelming.
Taxonomy is the branch of biology that names and classifies species.
The Three Domains of Life
The three domains of life are
Bacteria
Archaea
Eukarya

6. Chemistry of Life Matter is anything that occupies space and has mass.
Matter is found on the Earth in three physical states:
Solid
Liquid
Gas

7. Chemistry of Life Matter is composed of chemical elements.
Elements are substances that cannot be broken down into other substances.
Change the number of PROTONS in the nucleus and you change the ELEMENT

8. Atoms Each element consists of one kind of atom.
An atom is the smallest unit of matter that still retains the properties of an element.
Nucleus
Protons
Neutrons
Electrons
Cloud of negative
charge 2 electrons 2

9. Chemistry of Life
Elements differ in the number of subatomic particles in their atoms.
The number of protons, the atomic number, determines which element it is.
An atom’s mass number is the sum of the number of protons and neutrons.
Mass is a measure of the amount of matter in an object.

10. Periodic Table of the Elements
Other nonmetals
   
Halogens
Noble gases
Other metals
Rare earth metals
Transition metals
Alkali earth metals
Alkali metals
Synthetic
     
Gas
    
Liquid
Solid
Legend
Atomic number = number of protons within the nucleus

11. Chemistry of Life Twenty-five elements are essential to life.
Four elements make up about 96% of the weight of the human body:
Oxygen
Carbon
Hydrogen
Nitrogen
Carbon C: 18.5%
Hydrogen H:
9.5%
Nitrogen N:
3.3%
Calcium Ca: 1.5%
Trace elements: less than 0.01%
Boron B
Manganese Mn
Oxygen O:
65.0%
Magnesium Mg: 0.1%
Phosphorus P: 1.0%
Potassium K: 0.4%
Sulfur S: 0.3%
Sodium Na: 0.2%
Chlorine Cl: 0.2%
Cobalt Co
Chromium Cr
Iron Fe
Iodine I
Fluorine F
Copper Cu
Silicon Si
Zinc Zn
Vanadium V
Tin Sn
Molybdenum Mo
Selenium Se

12. Chemical Properties of Atoms
Electrons determine how an atom behaves when it encounters other atoms.
First electron shell
can hold 2 electrons
Outer electron shell
can hold 8 electrons
Hydrogen H
Atomic number = 1
Carbon C
Atomic number = 6
Nitrogen N
Atomic number = 7
Oxygen O
Atomic number = 8
Electron
© 2010 Pearson Education, Inc.

13. a pair of shared electrons two pairs of shared electrons
Covalent Bonds
A covalent bond forms when two atoms share one or more pairs of outer-shell electrons.
Atoms held together by covalent bonds form a molecule.
Name
molecular formula
Hydrogen gas H2
Oxygen gas O2
Methane CH4
Electron configuration
Structural formula
Space-filling model
Ball-and-stick model
Single bond
a pair of shared electrons
Double bond
two pairs of shared electrons

14. Sodium chloride (NaCl)
Ionic Bonds
When an atom loses or gains electrons, it becomes electrically charged.
Charged atoms are called ions.
Ionic bonds are formed between oppositely charged ions.
Outer shell
has 1 electron
has 7 electrons
The outer electron is stripped
from sodium and completes
the chlorine atom’s outer shell Na
Sodium atom Cl
Chlorine atom
Complete
outer shells
The attraction
between the
ions—an ionic
bond—holds
them together
Na
Sodium ion
Cl
Chlorine ion
Sodium chloride (NaCl)

15. Hydrogen Bonds
Water is a compound in which the electrons in its covalent bonds are shared unequally.
This causes water to be a polar molecule, one with opposite charges on opposite ends.
slightly 
slightly  H H O
slightly –

16. Hydrogen bonding Weak bonds formed between hydrogen and another atom
Surface tension of water
Important as intramolecular bonds, giving shape to proteins and other biomolecules