Unit 02 The Chemical Basis of Life 2.1 Introduction.

transcript

Unit 02

The Chemical Basis of Life

2.1 Introduction

2.1: Introduction

What do you think of when you hear the word chemistry?

Think and Share

2.1: Introduction Write

• Chemistry• The composition of matter and how it

changes.

2.2 Structure of Matter

2.2: Structure of Matter Write

• Matter• Anything that has mass and takes up space

• Mass –• A measure of how much matter is in an

object• Volume

• The amount of space taken up by matter

2.2: Structure of Matter

2.2: Structure of Matter Write

•Density• Ratio of Mass and Volume

Which box has more density?

Which cube is more dense?

2.2 Structure of MatterElements and Atoms

2.2: Structure of Matter Elements and Atoms Write

•Element• Any material that can’t be broken down

into a more fundamental substance

2.2: Structure of Matter Elements and Atoms

2.2: Structure of Matter Elements and Atoms Read

•There are 118 known elements

•20 of these elements make up the human body

Elements in the Human Body

I am mostly made up of….

2.2: Structure of Matter Elements and Atoms

• The type of element is determined by the type of atom.

• Do you remember the structure of an atom?

Draw an Atom

2.2: Structure of Matter Atomic Structure

2.2: Structure of Matter Elements and Atoms Write

•Atom• The basic unit of matter• The type of atom determines the type of

element

2.2 Structure of MatterAtomic Structure

2.2: Structure of Matter Atomic Structure Read

•An atom is composed of three particles

Proton (+) Neutron (N) Electron (e-)

2.2: Structure of Matter Atomic Structure Write

•Proton• Subatomic particle with a positive (+)

charge

•Neutron • Subatomic Particle with no charge (N)

•Electron• Subatomic Particle with a negative charge

•Nucleus• Center of an atom• Made up of Protons and Neutrons• Contains most of the mass

Nucleus

•Electron Shell• An orbit around the nucleus• Electrons can be found on electron shells

• Electrons on the outermost electron shell are called valence electrons

2.2: Structure of Matter Atomic Structure Write and draw

Valence Electron

Normal electron

Electron Shells

•Each electron shell can hold a certain amount of electrons

• 1st electron shell = 2 electrons• 2nd electron shell = 8 electrons• 3rd electron shell = 8 electrons

2.2: Structure of Matter Atomic Structure Write and draw

e- e-e-

1st2nd 3rd

Label the Parts of an Atom

Practice2.2: Structure of Matter Atomic Structure

•Balanced Atom• Protons = Neutron = Electron

• Isotope• Protons = Electrons

• More or less Neutrons than protons

• Ion• Protons = Neutrons

• More or less electrons than protons• Creates a positive or negative charge

Medical Isotopes Video

• https://www.youtube.com/watch?v=QI6lFbCj4gQ

2.2: Structure of Matter Atomic Structure Watch

Isotope Video

• Radioactive tracers:• https://www.youtube.com/watch?v=GHLBcCv4rqk

• Isotopes:• https://www.youtube.com/watch?v=cKJMk2Oiod0

2.2: Structure of Matter Atomic Structure Watch

Element Name

Atomic Number (Number of Protons)

Element Symbol

Atomic Mass (Avg. Weight)

2.2: Structure of Matter Elements and Atoms Practice

•The type of atom is determined by the Atomic Number (# of protons)

Protons = 1Neutrons = 0Electrons = 1

Circle the element this atom will make.Write the element name under the atom.

•Mass Number• The weight of the atom

• Proton mass + Neutron Mass• Electrons have very little mass so we don’t

count them• Not on periodic table of elements

Write2.2: Structure of Matter Atomic Structure

Formulas:

To find protons Look at the Atomic number

To find Neutrons mass number - atomic number

To find electrons electrons = charge - protons

(1 – 11 = -10)

Protons:___________

Neutrons:__________

Electrons:___________

Protons:___________

Neutrons:__________

Protons:___________

Neutrons:__________

2.2: Structure of Matter Atomic Structure Practice

15 protons, 16 neutrons, and 18 electrons __________

56 protons, 82 neutrons, and 54 electrons _________

13 protons, 14 neutrons, and 10 electrons __________

Draw the Isotopic Symbol for the following

Atomic # = ProtonsMass # = Protons + NeutronsCharge = Protons - Electrons

Practice

2.2 Structure of MatterBonding of Atoms + Molecules and Compounds

2.2: Structure of Matter Bonding of Atoms Write

•Chemical Bonding• an attraction between atoms that causes

them to bind and create molecules

•Molecule• Two or more atoms joined together

chemically

•Compound• A molecule that contains at least two

different elements.

Molecule

Compound

Compounds are a type of molecule.

All compounds are molecules but not all molecules are compounds.

2.1: Structure of Matter Molecules and Compounds Write

Why does chemical bonding occur?

• Every atom wants its outer electron shell full of electrons. This is why bonding between atoms occurs.

•Octet Rule• atoms create chemical bonds to achieve an

octet (8) of electrons in their outer most electron shell

•Two ways to obtain an octet:

• Ionization • Transfer of electrons

• Sharing

• Ionization• Occurs when an atom gives away or

receives an electron causing it to turn into an ion.

Ionization: How atoms become IonsNa is going to donate an electron to Cl. This fills Cl’s energy level and drops Na back to a full energy level.

Because of the number of electrons is no longer the same as the protons there is a negative and positive charge.

Read and Watch

Ionic Bond

Transfering electrons creates ions. Oppositely charged ions are attracted to one another (opposites attract). This attraction is an ionic bond.

Read and Watch

Covalent Bonds

Read and Watch

• Sharing Electrons. Both atoms obtain 8 electrons in their outer electron shell.

Chemical Bond Video

• http://chemistry.about.com/od/chemicalbonding/a/chemicalbonds.htm

2.2: Structure of Matter Bonding of Atoms

•Two types of Covalent Bonds:

• Non-polar Covalent Bonds• Electrons are shared equally• Results in a non-polar molecule

• Molecule does not have poles

• Polar Covalent Bonds• Electrons are shared unequally• Results in a polar molecule

• Molecules have positive and negative poles

Let’s Make Water

H HPositive Pole

Negative Pole

Listen

Polar Molecules Non-Polar MoleculesListen

2.1: Introduction Write

•Polar Molecule• A molecule that has positive and negative

poles due to uneven sharing of electrons. Created by polar covalent bonds.

•Nonpolar Molecules• A molecule that is neutral. Created by

nonpolar covalent bonds.

Hydrogen Bond

Read and Watch

• A bond formed between two polar molecules. A positive pole is attracted to a negative pole.

Listen

Ionic Bond Covalent Bond

Hydrogen Bond

One atom transfers (gives or takes) an electron to fill its outer energy level (ionization). The ions created from this transfer attract and form an ionic bond.

Two atoms share electrons to fill their electron shells

Two polar molecules bond together due to +/- charges

Three Types of Chemical Bonds

2.2 Structure of MatterFormulas

2.1: Structure of Matter Formulas Write

• Molecular Formula• Represents the numbers and types of

atoms in a molecule

Ca+2CO3

C6H12O6

Mg+2K+

Number of Elements

Overall Charge

•Structural Formulas• Represents how the atoms are bonded

together• 1 bond 2 bonds

• 3 Bonds 4 Bonds

2.2 Structure of MatterChemical Reactions

2.1: Structure of Matter Chemical Reactions Write

•Chemical Reactions• The rearrangement of atoms from one

arrangement to another.

•Law of Conservation of Mass• matter is not created nor destroyed during

a chemical reaction.

6H2O6CO26O2C6H12O6 + + + ATP + Heat

WaterCarbon Dioxide

OxygenGlucose + + + ATP + Heat

•Chemical Formula• a representation of a chemical

reaction Reactants Products

6H2O6CO26O2C6H12O6 + + + ATP + Heat(aq)

2.1: Structure of Matter Chemical Reactions

Types of chemical reactions

• Synthesis: A + B AB

• Decomposition: AB A + B

• Exchange Reaction: AB + CD AD + CB

• Reversible Reaction: A + B AB

•Exothermic Reactions• a chemical reaction that releases

energy by light or heat.• Example: Aerobic Respiration

•Endothermic Reactions• Chemical reaction that absorbs heat or light

• Example: Photosynthesis

WaterCarbon Dioxide OxygenGlucose + + + ATP+

6H2O6CO2 6O2C6H12O6 + + ATP+Sunlight+

Sunlight

•Activation Energy• minimum energy required for a chemical

reaction to occur• All chemical reactions have an activation

energy.

•Catalyst• Particular atoms or molecules (usually an enzyme) that

can change the rate of a reaction by lowering the activation energy

Activation Energy

Energy

Energy Needed to Break bonds

Lactase Enzyme

GLU GAL

Lactose

2.1: Structure of Matter Chemical Reactions

2.2 Structure of MatterAcids and Bases

2.1: Structure of Matter Acids and Bases Write

•Solution• Solute + Solvent

• Solute: Substance that is dissolved• Solvent: Substance that dissolves the solute (usually water)

• Some compounds release ions when they dissolve in water.

• NaCl Na+ + Cl-

•Electrolytes• Solutions that contain electrically charged particles (ions)

and will conduct an electric current• Acids and bases are examples of electrolytes

Hydroxide Ion (OH-)

Hydronium Ion(H3O+)

•Acids• Electrolytes that release (donate) hydrogen

ions (H+)• HCL (hydrochloric acid) H+ + Cl-

•Bases• Electrolytes that release hydroxide ions

(OH-)• NaOH (sodium hydroxide) Na+ + OH-

•pH• Measure of the the hydrogen ion

concentration in a solution

Acid Base

• pH Scale• pH<7 = acidic (0-6)• pH = 7 = neutral (7)• pH > 7 = Basic (8-14)

Organ, fluid or membrane pH Function of pH

(1) Skin Natural pH is between 4 and 6.5 Barrier protection from microbes

(2) Urine 4.6 to 8.0 Limit overgrowth of microbes

(3) Gastric 1.35 to 3.5 Break down protein

(4) Bile 7.6 to 8.8 Neutralize stomach acid, aid in digestion

(5) Pancreatic fluid 8.8 Neutralize stomach acid, aid in digestion

(6) Vaginal fluid <4.7 Limit overgrowth of opportunistic microbes

(7) Cerebrospinal fluid 7.3 Bathes the exterior of the brain

(8) Intracellular fluid 6.0–7.2 Due to acid production in cells

(9) Serum venous 7.35 Tightly regulated

(10) Serum arterial 7.4 Tightly regulated

2.1: Structure of Matter Formulas

•pH indicator• Anything that reacts to an acid or base by

changing color

Litmus Paper

Red Cabbage solution

Hydrangeas

http://www.shape.com/healthy-eating/diet-tips/alkaline-diet-real-deal

http://www.today.com/health/i-tried-alkaline-diet-what-its-summers-hottest-cleanse-trend-t37516

2.3 Chemical Constituents of Cells

•Organic Compounds• Contain both Carbon and Hydrogen

• Inorganic Compounds• Do not contain Carbon and Hydrogen

2.3 Chemical Constituents of CellsInorganic Substances

• Inorganic Substances• Water (H2O)

• Solvent• Most metabolic reactions occur in water

• Oxygen (O2)• Needed for cellular respiration

• Carbon Dioxide (CO2)• Waste

• Salts• Provide ions • Used for:

• Metabolic processes• Transport• Muscle contraction• Nerve impulse conduction

2.3 Chemical Constituents of CellsOrganic Substances

•Carbohydrates•Proteins•Nucleic Acids•Lipids

•Monomer• One thing

•Polymer• Many things

• A polymer is made up of many monomers.

Monomer Polymer

Dehydration Synthesis

Hydrolysis

•Dehydration Synthesis• Combining two monomers by taking

out a water

•Hydrolysis• Breaking apart two monomers by inserting

a water

Which is which?Dehydration Synthesis

Hydrolysis

•Carbohydrates• Common Name: Carbs or Sugars• Elements Present: CHO• Uses By Living Things: Energy and Structure

•Carbohydrates• Monomer: Monosaccharide• Polymer: Polysaccharide

• Example• Starch

• Breads• Glycogen

• Energy storage in your muscles• Cellulose

• Gives plants their structure• Chitin

• Exoskeleton of insects

Monosaccharide Polysaccharide

•Proteins• Common Name: Protein• Elements Present: CHON• Uses By Living Things: Structure, Transport, Communication,

Enzymes

•Proteins• Monomer: Amino Acid• Polymer: Polypeptide or protein

• Example• Cell Receptors

• Cellular communication• Antibodies

• Immune system• Enzymes

• Catalyze chemical reactions

Amino Acid Polypeptide or Protein

•Nucleic Acid• Common Name: DNA and RNA• Elements Present: CHONP• Uses By Living Things: Information

Storage and Transfer

2.1: Structure of Matter Formulas Listen

•Nucleic Acid• Monomer: Nucleotide• Polymer: Nucleic Acid

• Example• DNA • RNA

Nucleotide

•Lipids• Common Name: Fat• Elements Present: CHO• Uses By Living Things: Energy Storage

and Insulation

•Lipid• Lipids are not macromolecules• But they are still made up of parts

• 1. Glycerol Head• 2. Fatty Acid Chains

• Example• Triglycerides• Phospholipids• Testosterone and Estrogen

Glycerol

Triglyceride Phospholipid

Steroids From left to right: Cholesterol, Testosterone, and Estrogen

Functional Group

Structural Formula

Name of Compounds

Characteristics Draw an Example

Hydroxyl OH Alcohols Name ends in –ol

• Polar• Can form hydrogen

CarbonylC = O

Ketones • Soluble in water• Found in sugars

Carboxyl COOH Acids like vinegar (acetic acid)

• Polar• Soluble in water• acidic

Amine NH2 Amino Acids • Polar• Soluble in Water

Sulfahydryl SH Amino Acids • Stabilize protein structure

Phosphate PO4 ATP, DNA and RNA • Polar• Important in cellular

energy storage and transfer

Methyl CH3 Methylated Compounds

• Nonpolar• Important in

epigenetics

Unit 02 The Chemical Basis of Life 2.1 Introduction.

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