advanced placement biology
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Advanced Placement Biology
Mr. Jim SullivanBoston University
Boston University Project STAMP
• STAMP– Sciecne, Technology, And Math
Partnerships
Undergraduate- Boston CollegeStudy of Painted Turtles
Past:Undergraduate- Boston College
Study of Painted Turtles
Past:Graduate- University College
DublinNutrient 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 Life-The 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
612C
714N
15 30P
816O
16 32S
11H
How Do We Differentiate Between Atoms?
• Tell me how many neutrons, protons, and electrons are in the following elements
612C
714N
15 30P
816O
16 32S
11H
•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
612C
714N
15 30P
816O
16 32S
11H
•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
612C
714N
15 30P
816O
16 32S
11H
•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
612C
714N
15 30P
816O
16 32S
11H
•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
612C
714N
15 30P
816O
16 32S
11H
•16 protons, 16 neutrons, 16 e-
•15 protons, 15 neutrons, 15 e-
•8 protons, 8 neutrons, 8 e-
•7 protons, 7 neutrons, 7 e-
•6 protons, 6 neutrons, 6 e-
How Do We Differentiate Between Atoms?
• Tell me how many neutrons, protons, and electrons are in the following elements
612C
714N
15 30P
816O
16 32S
11H
•16 protons, 16 neutrons, 16 e-
•15 protons, 15 neutrons, 15 e-
•8 protons, 8 neutrons, 8 e-
•7 protons, 7 neutrons, 7 e-
•6 protons, 6 neutrons, 6 e-
•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
612 C
714 N
15 30 P
816 O
16 32 S
11 H
•These 6 elements, which you can remember as ‘SPONCH’ make up 97.6% of your body, by mass
Sulfur
Phosphorous
Oxygen
Nitrogen
Carbon
Hydrogen
How Do We Differentiate Between Atoms?
• Tell me how many neutrons, protons, and electrons are in the following elements
612 C
714 N
15 30 P
816 O
16 32 S
11 H
•Two other essential elements areCalcium (Ca) and Iron (Fe), which you remember as ‘CaFE.’•Using your Periodic Table, tell me howneutrons, 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 = 0.4C
H
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.
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