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Chapter 2
The Chemistry of Life
Section 1: The Nature of Matter
Objectives
• What three subatomic particles make up atoms?
• How are all the isotopes of an element similar?
• What are the two types of chemical bonds?
The Big Idea• Life Depends on chemistry
• Chemical reactions keep you alive
Atom• Basic unit of matter
Democrites
Subatomic particles• Protons - • Neutrons - • Electrons -
Positively charged (+)
Not charged (neutral)
Negatively charged (-)
Bind together to form the nucleus
Electrons Protons
Neutrons
Nucleus
Element• A pure substance that consists
of just one type of atom
6
CCarbon12.011
Atomic number
An elements atomic number = number of protons
Isotope• Atoms of the same element
that differ in the number of neutrons they contain
Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14
6 electrons6 protons6 neutrons
6 electrons6 protons8 neutrons
6 electrons6 protons7 neutrons
6
CCarbon12.011 Mass number
The Sum of protons and neutrons in the nucleus of an atom is its mass number
• The weighted average of the masses of an elements isotope is called its atomic mass
Radioactive isotopes• Can be dangerous
• Can be used practically–Radioactive dating
–Treat cancer
–Kill bacteria
Compounds• A substance formed by the
chemical combination of two or more elements in definite proportions
• Ex) H2O, NaCl
Table Salt
Ionic Bonds• Formed when one or more
electrons are transferred from one atom to another
Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)
Transferof electron
Protons +11Electrons -11Charge 0
Protons +17Electrons -17Charge 0
Protons +11Electrons -10Charge +1
Protons +17Electrons -18Charge -1
• If an atom loses an electron it becomes positive
• If an atom gains an electron it becomes negative
Ions• Positively and negatively
charged atoms
Covalent Bonds• Forms when electrons are
shared between atoms
Molecule• The structure that results when
atoms are joined together by a covalent bond
• Smallest unit of most compounds
Van der Waals Forces• A slight attraction that
develops between the oppositely charged regions of nearby molecules due to unequal sharing of electrons
Section 2: Properties of Water
Objectives• Why are water molecules polar?
• What are acidic solutions? What are basic solutions?
The Big Idea
• Much of our planet is covered in water
• Water is necessary for life to exist• If life exists on other planets, there
most likely is water present• Water has many properties that
make life possible
Polarity(-)
(+)
The oxygen atom has a stronger attraction for electrons
Hydrogen Bonds• Because of waters partial charges,
they can attract each other and create hydrogen bonds
• Not as strong as covalent or ionic bonds
• Waters ability to create multiple hydrogen bonds gives it many special properties
Cohesion• Attraction between molecules of
the same substance
Adhesion• Attraction molecules of different
substances
Mixture• Material composed of two or more
elements or compounds that are physically mixed but not chemically combined
• Ex.) salt & pepper, earths atmosphere
Solutions• Mixture of two or more
substances in which the molecules are evenly distributed
• Ex.) salt water
• Settles out over time
Solutions
Cl-
Water
Cl-
Na+
Water
Na+
Solute• Substance that is dissolved
• Ex.) salt
Solvent• The substance that does the
dissolving
• Ex.) Water
Suspensions• Mixture of water and non-
dissolved materials
• Ex.) sugar solution, blood
• Separate into pieces so small, they never settle out
The pH scale• Indicated the concentration of
hydrogen ions in a solution
Neutral
Acid
Base
Acids• Any compound that forms H+
(hydrogen) ions in solution
Base• A compound that produces OH-
(hydroxide) ions in solution
Buffers• Weak acids or bases that can
react with strong acids or bases to prevent sharp, sudden pH changes
Section 3: Carbon Compounds
Objective• What are the functions of each
group of organic compounds?
• Most of the compounds that make up living things contain carbon. In fact, carbon makes up the basic structure, or “backbone,” of these compounds. Each atom of carbon has four electrons in its outer energy level, which makes it possible for each carbon atom to form four bonds with other atoms.
• As a result, carbon atoms can form long chains. A huge number of different carbon compounds exist. Each compound has a different structure. For example, carbon chains can be straight or branching. Also, other kinds of atoms can be attached to the carbon chain.
Section 2-3
Interest Grabber
Life’s backbone
Methane Acetylene Butadiene Benzene Isooctane
Macromolecules “giant molecules”
• Formed by a process called polymerization
Monomers• Smaller units
Polymers• Linked up monomers
Carbohydrates• Compounds made up of carbon,
hydrogen, and oxygen atoms usually in a ratio of 1:2:1
• Main source of energy
• The monomers of starch are sugars
• Single sugar molecules are called monosaccharides
• The large macromolecules formed from monosaccharides are known as polysaccharides
Starch
Glucose
Lipids• Made mostly from carbon and
hydrogen atoms
• Used to store energy
Lipid Glycerol
Fatty Acids
Proteins• Macromolecules that contain
nitrogen as well as carbon, hydrogen, and oxygen
• Proteins are polymers of molecules called amino acids
Amino Acids
General structure Alanine Serine
Carboxyl group
• More than 20 different amino acids, can join to any other amino acid
• The instructions for arranging amino acids into many different proteins are stored in DNA
• Each protein has a specific role• The shape of proteins can be very
important
Proteins
Amino Acids
Nucleic Acids• Macromolecules containing hydrogen,
oxygen, nitrogen, carbon, and phosphorus
Double Helix
Nucleotides• Consists of 3 parts: 5-carbon sugar,
phosphate group and nitrogen base
Nitrogen Base
5-Carbon Sugar
Phosphate group
2 kinds of nucleic acids• RNA (ribonucleic acids) –
contains sugar ribose
• DNA (deoxyribonucleic acid) – contains sugar deoxyribose
Section 4: Chemical Reactions and Enzymes
Objectives• What happens to chemical bonds
during chemical reactions?
• How do energy changes affect whether a chemical reaction will occur?
• Why are enzymes important to living things?
The Big Idea• Living things are made up of
chemical compounds
• Everything that happens to an organism is based on chemical reactions
Chemical Reactions• A process that changes or
transforms one set of chemicals into another
Reactants• Elements or compounds that
enter into a reaction
Products
• Elements or compounds produced by a chemical reaction
Example Reaction: Getting rid of carbon dioxide
• In the blood
• In the lungs
CO2 + H20 H2CO3 (carbonic acid)
H2CO3 CO2 + H2O
Released as you breathe
Energy in reactions Energy-Absorbing Reaction Energy-Releasing Reaction
Products
Products
Activation energy
Activation energy
Reactants
Reactants
Activation Energy• The energy that is needed to get
a reaction started
Enzymes• Some chemical reactions are too
slow or have activation energies that are too high to make them practical for living tissue
• These chemical reactions are made possible by catalysts
Catalyst• Substance that speeds up the
rate of chemical reactions
• Work by lowering a reactions activation energy
Enzyme• Biological catalysts • Speed up reactions in cells• Very specific• Named for the reaction it catylzes• Enzyme names always end in -ase• Enzymes can be reused as long
as they are not denatured
Reaction pathwaywithout enzyme Activation energy
without enzyme
Activationenergywith enzyme
Reaction pathwaywith enzyme
Reactants
Products
Substrates• The reactants of enzyme
catalyzed reactions
• The active site of the enzyme and the substrate have complementary shapes
• Fit like a lock and key
Enzyme Action
Enzyme – substrate complex
Glucose
Substrates
ATP
Substratesbind toenzyme
Substratesare convertedinto products
Enzyme-substratecomplex
Enzyme(hexokinase)ADP
Products
Glucose-6-phosphate
Productsare released
Active site
Regulation of Enzyme Activity
• Enzymes are affected by any variable that affects chemical reactions
1. pH
2. Temperature
3. Concentration
of enzyme
M I N I L E S S O N: (10 - 15 mins)
CHEMICAL BASIS OF LIFE
CODE: GIVES WATCH
G lucose
I insulin
V accine
E strogen E nzymes
S tarch
W ater
A mino acids
A ntibodies
A ntigens
T estosterone
C atalyst H ormone
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
AGENDA
DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substanceACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet
Chemical Substances
Glucose - simple sugar
M I N I L E S S O N: (10 - 15 mins)
- building blocks of starch
GIVES WATCH AGENDA
State Standard 1,2 &4
CCSS: Grades 9-10 RST 4, 7
DO NOW:( 5 mins)
Match vocabulary words to their
correct description
MINI LESSON: ( 20-30 mins)
• Brainstorm the word chemicals
• Discuss the difference between
organic and inorganic
compounds• identify various
examples of organic compounds
• Identify and discuss various life processes
ACTIVITY:( 20-30 mins)
SlideshowSUMMARY( 10 mins )
HOMEWORK( 5 mins )
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
Chemical Substances
Insulin - hormone that regulates sugar in the blood
M I N I L E S S O N: (10 - 15 mins)
- produced by the pancreas
AGENDA
State Standard 1,2 &4
CCSS: Grades 9-10 RST 4, 7
DO NOW:( 5 mins)
Match vocabulary words to their
correct description
MINI LESSON: ( 20-30 mins)
• Brainstorm the word chemicals
• Discuss the difference between
organic and inorganic
compounds• identify various
examples of organic compounds
• Identify and discuss various life processes
ACTIVITY:( 20-30 mins)
SlideshowSUMMARY( 10 mins )
HOMEWORK( 5 mins )
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
Chemical Substances
Vaccine - consists of dead pathogens ( bacteria or viruses)-stimulates the body to produce antibodies
M I N I L E S S O N: (10 - 15 mins) AGENDA
State Standard 1,2 &4
CCSS: Grades 9-10 RST 4, 7
DO NOW:( 5 mins)
Match vocabulary words to their
correct description
MINI LESSON: ( 20-30 mins)
• Brainstorm the word chemicals
• Discuss the difference between
organic and inorganic
compounds• identify various
examples of organic compounds
• Identify and discuss various life processes
ACTIVITY:( 20-30 mins)
SlideshowSUMMARY( 10 mins )
HOMEWORK( 5 mins )
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
Chemical Substance
Estrogen - female reproductive hormone
M I N I L E S S O N: (10 - 15 mins)
AGENDA
DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substance
ACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet
- produced by the ovaries
- helps in the production of eggs
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
Chemical Substance
STARCH - made up of glucose molecules
M I N I L E S S O N: (10 - 15 mins)
AGENDA
DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substance
ACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet
- produced by plants
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
Chemical Substance
Antibodies
- produced by white blood cells
M I N I L E S S O N: (10 - 15 mins)
- protect the body against pathogens
White blood cells
antibodies
Pathogens
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
AGENDA
DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substance
ACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet
Chemical Substance
Amino acids
- building blocks of protein
M I N I L E S S O N: (10 - 15 mins)
T estosterone
- male hormones- produced by the testes
- helps in the production of sperm
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
AGENDA
DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substance
ACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet
Chemical Substance
M I N I L E S S O N: (10 - 15 mins)
C atalyst - chemical that speeds up chemical reaction.
- one example is an enzymeH ormon
e- chemical messengers that are responsible for cell communication
-Examples: Insulin, Estrogen, testosterone
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
AGENDA
DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substance
ACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet
Chemical Substance
Enzymes - a special type of protein that breaks down, cuts and speed up chemical reaction.
M I N I L E S S O N: (10 - 15 mins)
- most enzymes end with - ase
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
DO NOW QUIZ: (5-10 mins)
1. State what is in a vaccine that makes it effective.
2. Explain how a vaccine prevents future infections?
Vaccine is made up of dead or weakened virus or bacteria
Vaccine will make the body produce antibodies
3. Identify the genetic event that can change a flu virus strain into a different strain.
MUTATION
TOPIC: Use of Acronyms: GIVES WATCHAIM: How can we explain the importance of chemical substances in the living system?
AGENDA 11-18-15DO NOW: • Answer sample regents
question.
MINI LESSON: • Identify what each word from the code
give swatch represent.• Discuss
each example of chemical substanceACTIVITY:Slideshow
REFLECTION
HOMEWORK
HomeworkSheet