Professor’s eyes only…
You may be surprised to learn…
…that over 25% of all undergraduate students do not utilize
their required course material.
…student retention is dropping nationwide and while the
higher education community has done a remarkable job of
opening the doors of college to more and more students, we
have not seen equal strides in the number of students who
actually complete four-year degrees. (Education Trust, 2004)
See the next slide on what you can do…
Professor:
Course/Section:
Professor’s eyes only…
What you can do…
• The top factors motivating a student to use their adopted
books all involve whether the material is immediately used,
referred to, or assessed from in the classroom.
• Please take a few minutes the first day of class to explain
and demonstrate why you adopted your book and
accompanying technology.
• The next few slides show the book, technology products,
and messaging to students that indicates they will be
responsible for the content. Feel free to customize the
information or delete from your slide set.
Professor:
Course/Section:
Solomon/Berg/Martin
Biology, 8e
This is your required course material
You will need this material for:
- tests and quizzes
- homework and reading assignments
Professor:
Course/Section:
Some of the reasons why you need to use
the new edition…
• Based on instructor and student feedback, text and illustrations
throughout this edition have been extensively revised, honed, and
reorganized.
• Would you like to monitor your progress quickly and easily? Track your
progress with ease using innovative resources like ThomsonNOW
Foremost is a self-assessment diagnostic tool--ThomsonNOW for Biology-with automatic grading, which saves you time and helps you learn concepts
more efficiently.
Professor:
Course/Section:
ThomsonNow for Biology is a powerful online learning tool that
helps you assess your unique study needs, and available with
each new copy of Solomon/Berg/Martin’s Biology, 8e.
• On-line assessments/exams
• Animations/interactivities
• Point-of-use eBook
study less,
learn more!
Personalized Study
How Do I Prepare?
InfoTrac College Edition
• Do your research 24/7!
• Easy access to over 10 million full-text articles
• Nearly 5000 academic journals, magazines, and
periodicals.
• Do your research from home, work, or your
dorm room!
• InfoTrac can be used for ALL of your courses!
• Includes InfoWrite, a web-based training tool
designed to help you develop your writing skills.
Professor:
Course/Section:
HOW TO SEARCH THE DATABASE
There are 3 ways to search:
Subject Guide
Keyword Search
Advanced Search
There is also a Limit Search
function, which limits the search
by date, journal, or keyword.
IT’S EASY TO SEARCH BY SUBJECT OR KEYWORD!
STEP 1
STEP 2
STEP 3
Type in a subject
or keyword.
Click on View to see
search results, or click on
Narrow to narrow down
the search.
Once the article is
located, click on the
title to view.
INFOWRITE
InfoTrac College Edition, your Online Research and Learning Center,
includes InfoWrite, a web-based training tool designed to help you
develop your writing skills.
InfoWrite offers the following benefits:
•
Facilitates the writing process
•
Assists with the organization and presentation of ideas
•
Helps you articulate key concepts
•
Improves grammar, spelling and correct word usage
•
Aids your creativity
Also included:
•
Critical Thinking with InfoTrac
•
APA vs. MLA documentation style
•
Essay Topics
•
Research and the Internet
…and much more!
•
On-line live tutoring
from biology experts!
Professor:
Course/Section:
Essential Study Skills for Science Students
Written specifically for science students, this book
discusses how to develop good study habits, sharpen
memory, learn more quickly, get the most out of
lectures, prepare for tests, produce excellent term
papers, and improve critical-thinking skills.
Buy ISBN # 0534375952
• Your book may come
with an access card for
Biology’s e-resources.
Access your e-Resources
• Go to
www.thomsonedu.com
• Create or sign into your
Thomsonedu account.
• Enter the access code
found in the card.
Access your e-Resources
•
You should now have access to your e-resources for Biology. To access
resources in ThomsonNOW, click on the ThomsonNOW link.
Access your e-Resources
• First-time users: Set up your
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link up to your Thomsonedu
account.
Enter Your School Name
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Student Homepage
Enter a Course Key
Students Please Read…
If your textbook doesn’t already come with the
helpful study aids we’ve discussed, go to your
local college bookstore or go on-line to the
textbook URL …
http://www.thomsonedu.com/biology
Professor:
Course/Section:
Atoms and Molecules:
The Chemical Basis of
Life
Chapter 2
Learning Objective 1
•
What principal chemical elements are
found in living things?
•
What are the most important functions of
these elements?
Element
•
A substance that cannot be decomposed
into simpler substances by normal
chemical reactions
The Periodic Table
KEY CONCEPTS
•
Carbon, hydrogen, oxygen, and nitrogen
are the most abundant elements in living
things (about 96% of mass)
Element Functions
•
Carbon
•
•
Hydrogen and oxygen
•
•
backbone of organic molecules
components of water
Nitrogen
•
component of proteins and nucleic acids
Learning Objective 2
•
Compare the physical properties (mass
and charge) and locations of electrons,
protons, and neutrons
•
What is the difference between the atomic
number and the mass number of an atom?
Atom
•
Nucleus
protons (positive)
• neutrons (uncharged)
•
•
Electrons
encircle the nucleus
• negative
•
Atomic Number and Mass
•
Each atom is a particular element
•
•
identified by number of protons (atomic
number)
Atomic mass
•
sum of protons and neutrons
AMU
•
Atomic Mass Unit
•
•
Mass of a single proton or neutron
Mass of an electron
•
about 1/1800 amu
Isotopes
Carbon-12 (126 C)
(6p, 6n)
Carbon-14 (146 C)
(6p, 8n)
Fig. 2-2, p. 28
Learning Objective 3
•
What are orbitals and electron shells?
•
How are electron shells related to
principal energy levels?
KEY CONCEPTS
•
Chemical properties of an atom are
determined by its highest-energy (valence)
electrons
Orbitals
•
Electrons move rapidly in electron orbitals
•
•
Outside the nucleus
Electron shell
Electrons in orbitals at the same principal
energy level
• Electron in shell far from nucleus has more
energy than electron in shell close to nucleus
•
Atomic Orbitals
Nucleus
(a) The first principal energy level contains a
maximum of 2 electrons, occupying a single
spherical orbital (designated 1s). The electrons
depicted in the diagram could be present anywhere
in the blue area.
Fig. 2-4a, p. 30
(b) The second principal energy level includes four orbitals, each with a maximum
of 2 electrons: one spherical (2s) and three dumbbell-shaped (2p) orbitals at right
angles to one another.
Fig. 2-4b, p. 30
(c) Orbitals of the first and second principal energy levels of a neon
atom are shown superimposed. Note that the single 2s orbital plus
three 2p orbitals make up neon's full valence shell of 8 electrons.
Compare this more realistic view of the atomic orbitals with the
Bohr model of a neon atom at right.
Fig. 2-4c, p. 30
Learning Objective 4
•
How does the number of valence electrons
of an atom relate to its chemical
properties?
Valence Electrons
•
Electron in the outer shell
•
•
most energetic electrons
Number and arrangement of an atom’s
valence electrons
•
determine its chemical properties
Valence Electrons
•
An atom tends to lose, gain, or share
electrons to fill its valence shell
•
Electrons needed to fill valence shell
Most atoms: 8 electrons
• Hydrogen or helium: 2 electrons
•
Learning Objective 5
•
What is the difference between simplest,
molecular, and structural chemical
formulas?
Compounds
•
Atoms are joined by chemical bonds to
form compounds
•
A chemical formula gives the types and
relative numbers of atoms in a substance
Chemical Formulae
•
Simplest formula
•
•
Molecular formula
•
•
smallest whole-number ratio of component
atoms
actual numbers of each type of atom
Structural formula
•
the arrangement of atoms in a molecule
KEY CONCEPTS
•
A molecule consists of atoms joined by
covalent bonds
•
Other important chemical bonds include
ionic bonds and hydrogen bonds
Learning Objective 6
•
Why is the mole concept so useful to
chemists?
Avogadro’s Number
•
Avogadro’s number 6.02 x 1023
•
One mole (atomic or molecular mass in
grams) of any substance contains 6.02 x
1023 atoms, molecules, or ions
•
Enables scientists to “count” particles by
weighing a sample
Learning Objective 7
•
What is the difference between covalent
bonds, ionic bonds, hydrogen bonds, and
van der Waals interactions?
•
How does each differ in the mechanisms
by which they form and in relative
strength?
Covalent Bonds
•
•
•
•
Strong, stable bonds
Formed when atoms share valence
electrons
Form molecules
May rearrange the orbitals of valence
electrons (orbital hybridization)
Covalent Bonds
H H
Hydrogen (H)
Hydrogen (H)
Molecular hydrogen (H2)
or
H
H
(a) Single covalent bond formation. Two hydrogen atoms achieve stability by sharing a pair of electrons,
thereby forming a molecule of hydrogen. In the structural formula on the right, the straight line between
the hydrogen atoms represents a single covalent bond.
Oxygen (O)
Oxygen (O)
Molecular oxygen (O2) or
(double bond is formed)
O
O
O
O
(b) Double covalent bond formation. In molecular oxygen, two oxygen atoms share two pairs of
electrons, forming a double covalent bond. The parallel straight lines in the structural formula represent
a double covalent bond.
Fig. 2-5, p. 32
Nonpolar and Polar
Covalent Bonds
•
Covalent bonds are
nonpolar if electrons are shared equally
between the two atoms
• polar if one atom is more electronegative
(greater electron affinity) than the other
•
Ionic Bonds
•
Form between a positively charged cation
and a negatively charged anion
•
Are strong in the absence of water but
relatively weak in aqueous solution
Ionic Bonds
11 protons
17 protons
and
11 electrons
Sodium (Na)
17 electrons
Chlorine (Cl)
+
–
10 electrons
18 electrons
Sodium ion (Na+) Chloride ion (Cl–)
Sodium chloride (NaCl)
Fig. 2-9a, p. 35
Hydrogen Bonds
•
•
Relatively weak bonds
Form when
A hydrogen atom with a partial positive charge
• Is attracted to an atom (usually O or N) with a
partial negative charge
• Already bonded to another molecule or part of
the same molecule
•
Hydrogen Bonds
Electronegative
atoms
–
+
O
H
H
N
H
H
Hydrogen
bond
H
Fig. 2-11, p. 35
KEY CONCEPTS
•
Hydrogen bonds and van der Waals
interactions are weak attractions
van der Waals interactions
•
Weak forces
•
Based on fluctuating electric charges
Learning Objective 8
•
What are oxidation and reduction
reactions?
•
How do oxidation and reduction reactions
relate to the transfer of energy?
Redox Reactions
•
Oxidation and reduction reactions
•
Electrons (energy) are transferred from a
reducing agent to an oxidizing agent
Oxidation and Reduction
•
Oxidation
•
•
Atom, ion, or molecule loses electrons
(energy)
Reduction
•
Atom, ion, or molecule gains electrons
(energy)
KEY CONCEPTS
•
The energy of an electron is transferred in
a redox reaction
Learning Objective 9
•
How do hydrogen bonds between adjacent
water molecules govern the properties of
water?
Polar Molecules
•
Water is a polar molecule
•
One end has a partial positive charge and
the other has a partial negative charge
•
Because it is polar, water is an excellent
solvent for ionic or polar solutes
Polar Molecules
Oxygen part
Partial
negative
charge at
oxygen end
of molecule
Hydrogen (H)
Oxygen (O)
Hydrogen (H)
Water molecule (H2O)
Hydrogen
parts
Partial
positive
charge
at
hydrogen
end of
molecule
Fig. 2-7, p. 34
Oxygen part
Partial
negative
charge at
oxygen end
of molecule
Hydrogen (H)
Oxygen (O)
Hydrogen (H)
Water molecule (H2O)
Hydrogen
parts
Partial
positive
charge
at
hydrogen
end of
molecule
Stepped Art
Fig. 2-7, p. 34
Cohesion and Adhesion
•
Water molecules exhibit cohesion
because they form hydrogen bonds with
one another
•
Water molecules exhibit adhesion by
hydrogen bonding to substances with ionic
or polar regions
Hydrogen Bonds in Water
Specific Heat
•
•
•
Water has high specific heat
Hydrogen bonds must break to raise water
temperature
Specific heat of water helps
organisms maintain relatively constant
internal temperature
• keep large bodies of water (ocean) at a
constant temperature
•
Heat of Vaporization
•
Water has a high heat of vaporization
•
Hydrogen bonds must break for molecules
to enter vapor phase
•
Molecules carry heat, causing
evaporative cooling
Ice
•
Hydrogen bonds between water molecules
make ice less dense than liquid water
•
Because ice floats, the aquatic
environment is less extreme
Three Phases of Water
KEY CONCEPTS
•
Water molecules are polar, with partial
positive and negative charges
•
Form hydrogen bonds with one another
and other charged substances
Learning Objective 10
•
What is the difference between an acid
and a base?
•
What are the properties of acids and
bases?
Acids and Bases
•
Acids
proton (hydrogen ion, H+ ) donors
• dissociate in solution to yield H+ and an anion
•
•
Bases
proton acceptors
• dissociate in solution to yield hydroxide ions
(OH-)
•
KEY CONCEPTS
•
•
•
Acids are hydrogen ion donors
Bases are hydrogen ion acceptors
The pH scale measures the hydrogen ion
concentration of a solution
Learning Objective 11
•
How does the hydrogen ion concentration
(moles per liter) of a solution relate to its
pH value?
•
How do buffers help minimize changes in
pH?
pH
•
The negative log of the hydrogen ion (H+)
concentration of a solution
(measured in moles per liter)
pH of Solutions
•
Neutral solution
equal concentrations of H+ and OH• (10 -7 mol/L), pH 7
•
•
Acidic solution
•
•
pH less than 7
Basic solution
•
pH greater than 7
Buffers
•
Buffering system
•
•
based on a weak acid or a weak base
Buffer
•
resists changes in pH of a solution when
acids or bases are added
Learning Objective 12
•
What is the composition of a salt?
•
Why are salts are important in organisms?
Salts
•
Salt
•
•
a compound in which the hydrogen atom of
an acid is replaced by some other cation
Salts provide many mineral ions essential
for life functions
How Atoms Bond
CLICK
TO PLAY
Spheres of Hydration
CLICK
TO PLAY
The pH Scale
CLICK
TO PLAY
The Shell Model of Electron
Distribution
CLICK
TO PLAY