Chemistry of Life

Chapter #2 ST 110

OBJECTIVES Define Terms related to Chemical organization

Describe the structure of an atom

Compare and contrast ionic and covalent bonding

Distinguish between organic and inorganic compounds

OBJECTIVES

Discuss chemical characteristics of water

Explain the concept of pH

Discuss the structure and function of organic molecules

Life is ChemistryLife is Chemistry Food DigestionFood Digestion

Formation of bone tissueFormation of bone tissue

Contraction of musclesContraction of muscles

BIOCHEMISTRY

Studying chemical aspects of life

Levels of Chemical Organization Matter

Molecules

Atoms

ATOMS

Composed of subatomic particles

Protons

Electrons

Neutrons

Atoms

Nucleus Atomic number

Atomic mass

Atoms Electrons stay in certain limits called orbitals

Each orbital can hold two electrons

The closer to the nucleus, the lower the energy level

OrbitalsOrbitals The second energy level has four The second energy level has four

orbitalsorbitals

How many electrons can be held in How many electrons can be held in the second energy level?the second energy level?

IMPORTANCE????The outer number of electrons

determines how the atom “behaves chemically”

Elements

Element- pure substance of only one type of atom

Each element has a symbol

Example: Hydrogen Nitrogen Potassium

C.O.H.N.Four atoms that make up 96%

of the human body

Carbon Oxygen

Hydrogen Nitrogen

Molecules and CompoundsMolecules and Compounds Atoms unite with each other to form Atoms unite with each other to form

molecules. molecules.

Compounds have more than one Compounds have more than one element in them.element in them.

Compounds

The number of atoms in each molecule is expressed by a subscript

Example: CO2 = carbon dioxide one carbon, two oxygen's H2O2 = hydrogen peroxide two hydrogen’s, two oxygen’s

Compounds/Chemical BondingChemical bonds form to make atoms more stable

An atom is stable when it’s outer energy level is full

Atoms react to each other to make their outer most level full

Ionic Bonds

Electrons are donated

One atom will become negatively charged, and the other will become positively charged.

+++POSITIVE ION +++

• an ion that has given up its electron to another atom

---NEGATIVE ION---

• an ion that has borrowed an electron

Na-sodium – donates one electron then becomes positive

IONIC BONDS

Cl-chlorine- borrows one electron then it becomes negativeNa + Cl = NaCl (sodium chloride)

IONS

Ionic molecules dissolve easily in water

Dissociate- when ionic bonds break apart

Electrolytes- are molecules that form ions when

dissolved in water

QUESTION???????

What are the four main atoms thatmake up 96% of the human body?

QUESTION????????What is a positive ion?

What is a negative ion?

Covalent Bonds Covalent Bonds

Atoms can fill their energy level by sharing electrons

Covalent bonds do not break apart in water

Covalent Bonding

Question???

What is ionic bonding?

Question????

What is Covalent bonding?

Inorganic Chemistry Inorganic compounds do not contain Carbon-Carbon , or Carbon Hydrogen bonds

Few inorganic compounds have carbon in them

Inorganic compounds are smaller and less complex than organic compounds

H2OInorganic Compound

Why is water considered inorganic?

Solvent is a substance in which other substances are dissolved.Water is a

Solvent !!!Solute is a substance that dissolves into another substance.

Is it a solvent, or a solute?

Salt is a solute!!!

Mixture- a blend of two or morekinds of molecules

Aqueous solution - When water isthe solvent for two or more kindsof molecules

Dehydration Synthesis Synthesis- Is the reaction in which two reactants combine to form a product

Dehydration synthesis can only occur when a water molecule is removed from the reactants and then they bind to form a larger product.

HydrolysisHydrolysis Water disrupts the bonds in large Water disrupts the bonds in large

moleculesmolecules

The larger molecule is broken into The larger molecule is broken into smaller moleculessmaller molecules

Hydrolysis is the reverse of Hydrolysis is the reverse of dehydration synthesisdehydration synthesis

Chemical Reactions AlwaysInvolve Energy Transfers

Some energy is stored as potential energy in the chemical bonds

Ex: ATP (adenosine triphosphate)

pH Balanced !

Herbal Essence Shampoo? or something else?

pH balance is 7

Which way does an ACIDgo on the pH scale????Which numbers on the pHscale represent a base?

Acids are compounds that producean excess of H+ ions

Bases (alkaline) are compounds thatproduce an excess of OH- ions (or decreased in H+)

Isotopes Isotopes- two atoms with the same

atomic number, but different atomic mass

Metric SystemMetric System 1 meter= 39.37 inches1 meter= 39.37 inches

1 centimeter= 1/100 meter1 centimeter= 1/100 meter

1 millimeter= 1/1,000 meter1 millimeter= 1/1,000 meter

I micrometer= 1/1,000,000 meterI micrometer= 1/1,000,000 meter

End of Day 1End of Day 1

Questions???Questions???

Organic Chemistry

Much more complex than inorganic compounds

Larger than inorganic compounds

Organic Chemistry

Four major types of organic compounds Carbohydrates Lipids Proteins Nucleic Acids

Carbohydrates

Carbo-carbon hydrate-water

Basic unit of a carbohydrate is called monosaccharide

EX: Glucose important monosaccharide Primary source of energy

Carbohydrates

Disaccharide- a molecule made up of 2 saccharide units (double sugar)EX: Sucrose- table sugar Lactose- milk sugar• After eaten, the body digests them

to form monosaccharides to be used as cellular fuel

Carbohydrates

Polysaccharides- many saccharides joined together

Each glycogen molecule is a chain of glucose molecules joined together

EX: glycogen and starch

Liver cells and muscles cells form glycogen.Excess glucose in blood is stored for later use.

Carbohydrates

Carbohydrates have potential energy stored in their bonds

Lipids Lipid- fat and oils

At room temperature

Fats- solid lipid

Oils- liquid lipid

LipidsTriglycerides

• Bonds can be broken apart to yield energy• Store energy in cells for later use

Lipids Phospholipids

The phosphorus containing unit in each molecule forms a head that attracts water

Two fatty acid tails repel water

Cholesterol

Performs several important functions in the body

Combines with phospholipids in cell membrane to stabilize bi-layer structure

Body uses cholesterol to make steroid hormones. Estrogen, testosterone, cortisone

Proteins Very large molecule made of amino acids

Amino acids are held together by peptide bonds

Two types of proteinsStructural Functional

Proteins

Form Structures of the body

Collagen- fibrous protein that holds many tissues together

Keratin- forms tough waterproof fibers in outer layer of the skin

Structural Proteins

ProteinsFunctional Proteins

Participate in chemical processes

Hormones, cell membrane channels receptors, enzymes

Enzymes

Catalysts- aid in chemical reactions

Lock-and-key model

Proteins can combine with other organic molecules to form glycoproteins lipoproteins

Nucleic Acid

DNA-deoxyribonucleic acid• Master codeMaster code• Double helixDouble helix

Nucleic AcidRNA- ribonucleic acid

Working copy

Nucleic Acid

Made of nucleotide units

Sugar (ribose, or deoxyribose)

Phosphate- nitrogen based adenine, thymine or uracil, guanine cytosine

What are the four major types of What are the four major types of organic compounds found in the organic compounds found in the

body?body?

What is glycogen?What is glycogen?

What is the primary source of What is the primary source of energy for cells?energy for cells?

What are lipids?What are lipids?

What are proteins made of?What are proteins made of?

What is an enzyme?What is an enzyme?

What are the two types of What are the two types of nucleic acids?nucleic acids?

What are the nitrogen bases?What are the nitrogen bases?

What shape is DNA?What shape is DNA?

End of Day 2End of Day 2

Questions???Questions???