Anatomy & Physiology

Chapter 2Week 1Ms. Darlak

Warm-up 09/23

• Name as many elements important to all living things as you can?

• What’s an element? HINT: Au = Gold.

Elements Important to Life

Basic Nutrients• Hydrogen• Oxygen• Carbon• Nitrogen• Phosphorous

Macronutrients• Sodium• Iron• Chlorine• Sulfur• Potassium• Magnesium

Agenda 09/23

• Biochemistry Pre-Test• What don’t I know?

Chapter 2The Chemistry of Life

• Atoms, Ions and Molecules• Properties of Water• pH• Energy and Chemical

Reactions• Organic compounds

The Chemical Elements

• Element – simplest form of matter with unique chemical

properties• Atomic number of each element

– number of protons in its nucleus• Periodic table

– letter symbols of elements arranged by atomic number 118 elements (many man-made)

• Only 24 elements have a role in our body– 98.5% of body weight consists of

• O, C, H, N, Ca, P

• Nucleus – center of the atom– Home of Protons and Neutrons

–Proton• Has a positive (+) charge• Has a relative mass of 1• Determines the atomic number• Found inside the nucleus

What is the structure of an atom?

–Neutron• Has no (0) charge• Has a relative mass of 1• Determines the isotope

– Isotopes are two of the same element with different masses

• Found inside the nucleus

What is the structure of an atom?

What is the structure of an atom?

• Electron– Has a negative (-) charge– Has a relative mass of 0 (zero)– Determines the ion– Found outside the nucleus

• Bohr model – electrons are in specific energy levels

• Electron cloud model – electrons are in a random cloud

What is the structure of an atom?

Bohr Model“Planetary Model”

Schrödinger Model“Electron Cloud Model”

Atomic Structure• Nucleus - center of atom contains

– protons: positive charge, mass of 1 amu– neutrons: neutral charge, mass of 1 amu– atomic mass = total # of protons + neutrons

• Electron shells – electrons: negative charge– # of electrons = # of protons, atoms have neutral charge– electrons further from nucleus have higher energy– valence electrons are in the outermost shell

• interact with other atoms• determine chemical behavior• octet rule - atoms react to obtain a stable number of 8

valence electrons

ATOMIC STRUCTURE

Electrons are arranged in Energy Levels or

Shells around the nucleus of an atom.

• first shell a maximum of 2 electrons

• second shell a maximum of 8 electrons

• third shell a maximum of 8 electrons

Valence Electrons

• Each electron shell can hold a certain number of electrons

• Electron shells are filled from the inside out

• Noble Gases have full outer electron shells

• All other elements have partially filled outer electron shells

Electron Shell

Number of Electrons

1 2

2 8

3 8

4 18

5 18

6 32

7 32

DOT DIAGRAMS

With Dot diagrams elements and compounds are

represented by Dots to show electrons, and circles

to show the shells. For example:

Nitrogen N XX X

X

XX

X

N7

14

DOT DIAGRAMS

Draw the Dot diagrams for the following elements;

O Cl

8 17

16 35a) b)

X

XX

X

X

X

X

X

XCl

X

X

X

X X

X

XX

X

X

X

X

XX

X

X

X

O

The outermost electron shell is referred to as the valence shell.

DOT DIAGRAMS

Valence Electrons

• The electrons in the outer most electron shell are called valence electrons

• The shell containing electrons that is furthest from the nucleus is called the valence shell

• The number of electron shells with electrons is the same as the period number

Columns- Families

• Move left to right, valence electron number changes and reactivity.

Rows - Periods• As you move up and down, the number of

filled energy levels (shells) changes

Warm-up 09/24

• How are P+, N0, e- similar and different? • How are they related?

– Same• Protons and Neutrons are in the nucleus• Protons and Neutrons have an amu of 1.

– Different• Protons-pos, electrons-neg, neutrons-neutral• Electrons are outside nucleus• Electrons involved in bonding

– Related• # protons = atomic number• # electrons = # protons in a neutral atom• # protons + # neutrons = atomic mass

Agenda 09/24

• Chapter 1 Tests Back• Review: Isotopes, Ions• Electrolytes and Free Radicals• Molecules and Chemical Formulas• Balancing Equations• HW: p.5 in packet.

Isotopes and Radioactivity Isotopes

› elements that differ in the number of neutrons 1H, 2H, 3H

› extra neutrons result in increased atomic weight “heavy water”

› have no change in chemical behavior same valence electrons

Atomic weight› Average atomic mass of the mixture of isotopes of

an element found in a sample

• Anion (-) gains electron, net negative charge

• Cation (+) loses an electron, net positive charge

Anions and Cations

Electrolytes

• Salts that ionize in water, form solutions capable of conducting electricity

• Bodies most abundant electrolytes– Na+, Ca2+, Mg2+, Cl-, PO4

3- and HCO3-

• Essential to nerve and muscle function• Imbalance effects range from muscle cramps,

brittle bones to coma and death

Free Radicals• A particle with an odd number of electrons

– superoxide anion O2-.

• oxygen molecule with an extra electron

• Produced by – metabolic reactions, radiation, chemicals

• Causes tissue damage– triggers chain reactions that destroy molecules

• Antioxidants– neutralize free radicals

• SOD (superoxide dismutase enzyme)• vitamin E, carotenoids, vitamin C

Molecules and Chemical Bonds

• Molecules– two or more atoms covalently bonded

• Compounds– two or more different atoms chemically bonded

• Molecular formula – itemizes each element present and its quantity

• Structural formula– shows arrangement of atoms– needed to show structural isomers

Counting Atoms in Molecular Formulas

How many atoms of each element are in the following molecules?

1. H2SO4

2. Ca(OH)2

3. NaCl4. (NH3)3P04

5. 3H2O

6. 4Al2(CO3)3

Answers

1. H2SO4: 2 hydrogen, 1 sulfur, 4 oxygen2. Ca(OH)2 1 calcium, 2 oxygen, 2 hydrogen3. NaCl 1 sodium, 1 chlorine4. (NH3)3P04 3 nitrogen, 9 hydrogen, 1

phosphorus, 4 oxygen5. 3H2O 6 hydrogen, 3 oxygen6. 4Al2(CO3)3 8 aluminum, 12 carbon, 36

oxygen

Balancing Equations

• Hydrogen and oxygen are diatomic elements.• Their subscripts cannot be changed.• The subscripts on water cannot be changed.

Hydrogen + oxygen water

H2 + O2 H2O

Balancing Equations

• Count the atoms on each side.– Reactant side:

• H= 2 atoms• O= 2 atoms

H2 + O2 H2O

– Product side:• H= 2 atoms• O= 1 atom

Not Balanced!

Balancing Equations

H2 + O2 H2O

• If the subscripts cannot be altered, how can the atoms be made equal?

• Adjust the number of molecules by changing the coefficients.

Balancing Equations

• Reactants: – H= 2 atoms – O= 2 atoms

H2 + O2 2H2O

• Products: – H= 4 atoms – O= 2 atoms

• H is no longer balanced!

Balancing Equations

• Reactant side: – H= 4 atoms – O= 2 atoms

2H2 + O2 2H2O• Product side:

– H= 4 atoms – O= 2 atoms

• It’s Balanced!

Warm-up 09/25

Is this equation balanced?• NaCl + H2O NaOH + HCl• left side has 1Na, 1Cl, 2H, and 1O• right side has 1Na, 1Cl, 2H, and 1O

• YES!!!!!! It is balanced!!

Agenda 09/25

• Balancing Equations• Bonding• Chemical Reactions

Practice Check……

• Complete Practice #1• Complete page 5 in packet

Balancing Equations p.5

1) ____ Na3PO4 + ____ KOH ____ NaOH + ____ K3PO4

2) ____ MgF2 + ____ Li2CO3 ____ MgCO3 + ____ LiF

3) ____ P4 + ____ O2 ____ P2O3

4) ____ RbNO3 + ____ BeF2 ____ Be(NO3)2 + ____ RbF

5) ____ AgNO3 + ____ Cu ____ Cu(NO3)2 + ____ Ag

3 3

2

3 2

2 2

2 2

6) ____ CF4 + ____ Br2 ____ CBr4 + ____ F2

7) ____ HCN + ____ CuSO4 ____ H2SO4 + ____ Cu(CN)2

8) ____ GaF3 + ____ Cs ____ CsF + ____ Ga

9) ____ BaS + ____ PtF2 ____ BaF2 + ____ PtS

10) ____ N2 + ____ H2 ____ NH3

Balancing Equations p.5

2 2

2

3 3

3 2

Chemical Bonds

• Ionic bonds• Covalent bonds• Hydrogen bonds

Types of Chemical Bonds p.61. Ionic: bond between a metal and non-metal,

complete transfer of e- from one atom to another

a. Forms Ions or charged particlesi. Cation (+) loose e-ii. Anion (-) gains e-

b. Valence Electron scenarios- atom needs 1 or 2 (takes), atom only has 1 or 2 (gives)

• Animation

Ionic

• IONIC= metal and nonmetal

Sodium Chloride Lattice

Sodium Chloride Crystals

2. Covalent: bond between 2 non-metals where they share electrons (share valence e-)

a. Single or Double bondsb. Polar or Non-polar

• Non-polar = e- shared equally• Polar = e- not shared equally creates “poles” on a

molecule +/-

• Animation

Types of Chemical Bonds p.6

Covalent

• COVALENT= two non-metals

Single Covalent Bond

• One pair of electrons are shared

Single Covalent Bond

Double covalent bonds: Two pairs of electrons are shared with each C=O bond

Nonpolar /Polar Covalent Bonds

electrons shared equally

electrons shared unequally

Hydrogen Bonds p. 6• Attraction between polar molecules –

no sharing of electrons• 5 % strength of covalent bonds • Greatest physiological importance

– properties of water– shapes of complex molecules

• proteins, DNA

Hydrogen Bonding in Water

Warm-up 09/26

• Which of the following compounds are ionic and which are covalent?

a. water (H2O)

b. ammonia (NH3)

c. sodium oxide (Na2O)

d. potassium nitrate (KNO3)

e. sulfur(VI) oxide (SO2)

f. manganese(IV) sulfide (MnS2)

g. carbon tetrachloride (CCl4)

Answers

a. water - covalentb. ammonia - covalentc. sodium oxide - ionicd. potassium nitrate - ionice. sulfur(VI) oxide - covalentf. manganese(IV) sulfide - ionicg. carbon tetrachloride - covalent

Agenda 09/26

• Bonds• Patterns of Chemical Reactions• Properties of Water

Ions and Bonding p.6Element Metal

or Non- Metal

#Valence Electrons

Type of Bond (Covalent /Ionic)

Produce Ion? (Cation/Anion)

Example Molecules

CarbonHydrogenOxygenNitrogenCalciumPhosphorusPotassiumSulfurSodiumChlorineMagnesiumIodineIronZinc

Non 4 Covalent no CH4, CO2Non 1 Either + CH4, H2ONon 6 Either * - H2O, K2ONon 5 Covalent no NH3Metal 2 Ionic + CaF2Non 5 Covalent no PO4

Metal 1 Ionic + KClNon 6 Either * - S2F2, SO

Metal 1 Ionic + NaClNon 7 Ionic - NaClMetal 2 Ionic + MgF2Non 7 Ionic - KIMetal 2 Ionic + FeOMetal 2 Ionic + ZnO

Patterns of Chemical Reactions p. 6

• A chemical bond is formed or broken• A chemical equation shows:

– reactants products

Synthesis Reactions

1. Synthesis- Two or more small molecules combine to form a larger one

a. Bonds are formed A + B ABb. Energy is absorbedc. Anabolic reaction (building)d. Usually endergonic (energy

required)e. Decreases entropyf. EXAMPES: making new cells,

storing fat, making proteins

Amino acids

Protein molecule