Chapter 2 The Chemistry of Life Section 1: The Nature of Matter

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

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


- 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 )


Chemical Substances

Insulin - hormone that regulates sugar in the blood


- produced by the pancreas

AGENDA



DO NOW:( 5 mins)


correct description










HOMEWORK( 5 mins )


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



DO NOW:( 5 mins)


correct description










HOMEWORK( 5 mins )


Chemical Substance

Estrogen - female reproductive hormone


AGENDA


question.



each example of chemical substance

ACTIVITY:Slideshow

REFLECTION

HOMEWORK

HomeworkSheet

- produced by the ovaries

- helps in the production of eggs


Chemical Substance

STARCH - made up of glucose molecules


AGENDA


question.




ACTIVITY:Slideshow

REFLECTION

HOMEWORK

HomeworkSheet

- produced by plants


Chemical Substance

Antibodies

- produced by white blood cells


- protect the body against pathogens

White blood cells

antibodies

Pathogens


AGENDA


question.




ACTIVITY:Slideshow

REFLECTION

HOMEWORK

HomeworkSheet

Chemical Substance

Amino acids

- building blocks of protein


T estosterone

- male hormones- produced by the testes

- helps in the production of sperm


AGENDA


question.




ACTIVITY:Slideshow

REFLECTION

HOMEWORK

HomeworkSheet

Chemical Substance


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


AGENDA


question.




ACTIVITY:Slideshow

REFLECTION

HOMEWORK

HomeworkSheet

Chemical Substance

Enzymes - a special type of protein that breaks down, cuts and speed up chemical reaction.


- most enzymes end with - ase


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


AGENDA 11-18-15DO NOW: • Answer sample regents

question.



each example of chemical substanceACTIVITY:Slideshow

REFLECTION

HOMEWORK

HomeworkSheet

Documents

Chapter 2 The Chemistry of Life Section 1: The Nature of Matter