Advanced Placement Biology
Mr. Jim Sullivan
Boston University
Boston University Project
STAMP
• STAMP
– Sciecne, Technology, And Math
Partnerships
Undergraduate- Boston College
Study of Painted Turtles
Past:
Undergraduate- Boston College
Study of Painted Turtles
Past:
Graduate- University College Dublin
Nutrient Cycling
Graduate- University College Dublin
Nutrient Cycling
Past:
‘Radio’-pharmaceuticals
• Using ‘radioactive’
chemicals to create
therapeutic
medicines
• Designed to fight
cancer
Present:
• Boston University
– Ecology
– Molecular Biology
– Environmental
Chemistry
• You!
– Working with you
guys.
– Exploring and
understanding
biology from the
molecular to the
organismal level
Nematostella vectensis
Time for the flashlight!
• Before going into Genetics, we need to
review basic chemistry
Time for the flashlight!
• Before going into Genetics, we need to
review basic chemistry
• Why is Chemistry important for
understanding biology?
The Building Block of LifeThe Atom
What are atoms comprised of?
What are atoms comprised of?
• Neutrons, Protons, and
Electrons
• Neutrons
– Electrically neutral
– Found in nucleus
– Have mass
• Protons
– Positively charged
– Found in nucleus
– Have mass
• Electrons
– Negatively charged
– Encircle the nucleus
– Do not have mass
Contains protons
and protons
Define Mass
Define Mass
• Mass is an important unit of measurement
which will come up often throughout the
year.
• Mass is a measure of ‘matter.’
• It is a function of both the density and the
size of the object in question.
• Are mass and weight identical?
How do we describe atoms?
• We define different atoms based upon the
number of each of their three components.
• What are the three parts of an atom
again?
How do we describe atoms?
• We define different atoms based upon the number
of each of their three components.
– Neutrons, Protons, and Electrons
• Each atom has a unique number of protons.
• Atoms are (usually) electrically neutral, so the
number of electrons equals the number of protons.
• The atomic mass describes the sum of protons and
neutrons
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
15
30P
8
16O
7
14N
6
12C
1
1 H
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
15
30P
8
16O
7
14N
6
12C
1
1 H
•16 protons, 16 neutrons, 16 e-
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
15
30P
8
16O
7
14N
6
12C
1
1 H
•16 protons, 16 neutrons, 16 e•15 protons, 15 neutrons, 15 e-
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
15
30P
8
16O
7
14N
6
12C
1
1 H
•16 protons, 16 neutrons, 16 e•15 protons, 15 neutrons, 15 e-
•8 protons, 8 neutrons, 8 e-
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
15
30P
8
16O
7
14N
6
12C
1
1 H
•16 protons, 16 neutrons, 16 e•15 protons, 15 neutrons, 15 e-
•8 protons, 8 neutrons, 8 e•7 protons, 7 neutrons, 7 e-
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
15
30P
8
16O
•16 protons, 16 neutrons, 16 e•15 protons, 15 neutrons, 15 e-
•8 protons, 8 neutrons, 8 e-
7
14N
•7 protons, 7 neutrons, 7 e-
6
12C
•6 protons, 6 neutrons, 6 e-
1
1 H
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32S
16
•16 protons, 16 neutrons, 16 e-
15
30P
•15 protons, 15 neutrons, 15 e-
8
16O
•8 protons, 8 neutrons, 8 e-
7
14N
•7 protons, 7 neutrons, 7 e-
6
12C
•6 protons, 6 neutrons, 6 e-
1
1 H
•1 proton, 0 neutrons, 1 e-
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32
S
30
P
16
O
14
N
•These 6 elements, which
Phosphorous you can remember as
‘SPONCH’ make up
Oxygen
97.6% of your body, by
mass
Nitrogen
12
C
Carbon
1
1
H
Hydrogen
16
15
8
7
6
Sulfur
How Do We Differentiate Between
Atoms?
• Tell me how many neutrons, protons, and
electrons are in the following elements
32
S
30
P
16
O
14
N
12
C
1
1
H
16
15
8
7
6
•Two other essential elements are
Calcium (Ca) and Iron (Fe), which you
remember as ‘CaFE.’
•Using your Periodic Table, tell me how
neutrons, protons, and electrons are
present in atoms of these elements
Bonds
• What is a bond?
Bonds
• What is a bond?
– A bond between atoms is the result of
interactions bringing atoms closer together
• Name different types of bonds
Types of Bonds
• There are four types of bonds that will be
important to us throughout the year:
– Ionic Bonds
– Covalent Bonds
– Hydrogen Bonds
– van der Waals Interactions
• For now, you should understand Ionic and
Covalent bonds, we’ll cover the others
later
Ionic and Covalent Bonds
• These bonds are interactions between
atoms in which each of the atoms involved
attempts to fill its valence shell with eight
electrons
• In ionic bonds, there is taking and giving
of electrons
• In covalent bonds, there is a sharing of
electrons
Ionic Bonds- The Bully
• Look for the ‘electronegativity (δ)’ section of your periodic
table.
• This number indicates how strongly electrons are drawn
to the nucleus of that particular atom; the higher the
number, the greater the affinity
• If the difference of electronegativities (δ) of
atoms which share a bond is ≥ 1.5, then
the bond is ionic
• The more electronegative atom involved ‘takes’ the
electrons from the less electronegative
Covalent Bonds- Friendly Atoms
• If the difference between
electronegativities (δ) of atoms sharing a
bond is < 1.5, then the atoms in the bond
are sharing the electrons
– These are Covalent Bonds
Just to confuse you…
• There are two types of covalent bonds
– Non-polar
– Polar
Just to confuse you…
• There are two types of covalent bonds
– Non-polar
– Polar
• In Non-polar Covalent bonds, the electrons are
shared almost completely equally
– CH4 is an example
– The difference in terms
of δ between C and H is
2.6 - 2.2 = 0.4
H
C
H
H
H
Just to confuse you…
• There are two types
of covalent bonds
– Non-polar
– Polar
•In Polar Covalent Bonds, the electrons are still shared…
but not as equally. H2O is an example
•The difference in electronegativities (δ) between O (3.4)
and H (2.2) is 3.4 – 2.2 =1.2
•This is still a covalent bond, but one in which electrons are
not evenly shared
•The polar nature of water gives it unique properties!
Ionic or Covalent?
NaCl
Ionic or Covalent?
NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt
N2
Ionic or Covalent?
NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt
N2- Covalent (3.0 – 3.0 = 0) Dinitrogen gas, makes up ~78%
of the air we breathe
CH4
Ionic or Covalent?
NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt
N2- Covalent (3.0 – 3.0 = 0) Dinitrogen gas, makes up ~78%
of the air we breathe
CH4- Covalent (2.6 – 2.2 =0.4) Methane, aka Natural Gas
HF
Ionic or Covalent?
NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt
N2- Covalent (3.0 – 3.0 = 0) Dinitrogen gas, makes up ~78%
of the air we breathe
CH4- Covalent (2.6 – 2.2 =0.4) Methane, aka Natural Gas
HF- Ionic (4.0 – 2.2 = 1.8) Hydrogen flouride
Review
• What are the three components of an
atom?
Review
• What are the three components of an
atom?
• How can we interpret the periodic table.
– Write down the number of protons, electrons,
and neutrons for five elements. Write down
the electronegativity of each also.
Review
• What are the three components of an
atom?
• How can we interpret the periodic table.
– Write down the number of protons, electrons,
and neutrons for five elements. Write down
the electronegativity of each also.
• What is a bond?
– Name four types of bonds
Review
• What are the three components of an atom?
• How can we interpret the periodic table.
– Write down the number of protons, electrons, and
neutrons for five elements. Write down the
electronegativity of each also.
• What is a bond?
– Name four types of bonds
• What is the difference between an ionic and a
covalent bond?
Review
• What are the three components of an atom?
• How can we interpret the periodic table.
– Write down the number of protons, electrons, and
neutrons for five elements. Write down the
electronegativity of each also.
• What is a bond?
– Name four types of bonds
• What is the difference between an ionic and a
covalent bond?
• What are the two types of covalent bonds?
Back to the Future!
• Next class we will cover Chapter 3.
– This will be a discussion of the unique
properties of water, thanks to the polar
covalent bonds H2O forms.
• We will also introduce some of the
concepts from Chapter 5
• After that, we will begin our discussion of
Unit 3: Genetics
Homework for next Teusday
•
•
•
•
Review the handouts from this class
Read Chapter 3.
Read pages 52-54.
Skim Chapter 5. Look at all of the figures
and read the figure legends. Don’t worry
about the details.