Chemistry of Life

At the Completion of this Unit, Students will be able to:• List the major chemical elements in cells and know their chemical symbols

and explain why they are essential to life (i.e. carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, potassium, and trace elements)

• Explain the properties of water and describe why these properties are important to life. (Cohesion, adhesion, less dense as a solid, heat capacity, solvent properties, pH)

• Identify the function of the 4 groups of macromolecules, how they are formed

• (Carbohydrates, proteins, lipids, nucleic acids) and describe their structure.• Explain the role of enzymes in living organisms

What makes up the chemistry of life? Adam or Atom The study of chemistry begins with the basic unit of matter, the

atom.

The Greek word atomos, which means “unable to cut”.

This word was first used nearly 2500 years ago by Greek philosopher Democritus.

Democritus asked a simple question “If you take an object like chalk and break it in half are both pieces still chalk?”

Yes, suppose you break the chalk down again and again and again. Can you continue to divide without limit? Or is there a limit? Democritus thought there was a limit.

Democritus called the smallest fragment the atom, a name scientists use today.

A. Students will be able to identify and define the parts of an atom

Chemistry of Life

Atoms – the SMALLEST particle that can exist and still be considered a certain kind of matter

All LIVING and NONLIVING things are made of atoms

A. Identify and define the parts of an atom

Atoms -- have three components

ELECTRONS -- negatively charged

PROTONS -- positively charged; found in nucleus

NEUTRONS -- neutral; found in nucleus

A. Identify and define the parts of an atom

Electrons

Protons& Neutrons (Nucleus)

Energy Levels

A. Identify and define the parts of an atom

B. Demonstrate how to use the Periodic Table of Elements

B. Demonstrate how to use the Periodic Table of Elements

Atomic Number = # of Protons and # of Electrons

Carbon

Chemical Symbol

Chemical Name

Atomic Weight =# of Protons + Neutrons

Carbon

Atomic Number = # of Protons and # of ElectronsChemical SymbolChemical NameAtomic Weight =

# of Protons + Neutrons

P = 6 E = 6 N = 6 (Atomic Weight – Atomic # = Neutrons)

Remember: No more than 2 electrons on first ring, No more than 8 on second

B. Demonstrate how to use the Periodic Table of Elements

Chemistry of Life

• Elements -- a substance that is made of only ONE kind of ATOM

Major Elements of Life

• C = Carbon• H = Hydrogen• O = Oxygen• P = Phosphorus• K = Potassium

Major Elements of Life

• I = Iodine• N = Nitrogen• S = Sulfur• Ca = Calcium

Major Elements of Life

• Fe = Iron• Mg = Magnesium• Na = Sodium• Cl = Chlorine

Where do we find these elements?

• In all living and nonliving things.

Major Elements in Human Body

Chemistry of Life

Compounds – matter that is made of more than ONE kind of ATOM

Compounds are made by atoms sharing or taking ELECTRONS from the other atoms in the compound

Compound Example

Water ( H2O ) – each molecule is made of two HYDROGEN atoms and one OXYGEN atom

Water Molecule

Chemical Bonds

The main types of Chemical Bonds in a compound are: Ionic Bonds Covalent Bonds

Ionic Bonds

An IONIC BOND is formed when one or more electrons are transferred from one atom to another.

Ionic Bond Example

Covalent Bonds

A COVALENT BOND is formed when electrons are shared between atoms.

Single bond: Share two electrons Double bond: Share four electrons Triple bond: Atoms share six or more

electrons

MOLECULE. The structure that results when atoms are joined together by a covalent bond.

Covalent Bond Example

The Water Molecule One atom of oxygen binds to two atoms of hydrogen

to form H20. Like all molecules a water molecule (H20) is neutral. Water molecules are held together by a hydrogen

bond. Hydrogen Bonds are not as strong as covalent or

ionic bonds. The hydrogen atoms are attached to one side of the

oxygen atom, resulting in a water molecule having a positive charge on the side where the hydrogen atoms are and a negative charge on the other side, where the oxygen atom is.

Since opposites attract, water molecules tend to attract each other, making water kind of "sticky."

The Water Molecule

Properties of Water

Cohesion is an attraction between molecules of the same substance.

- Example: molecules on the surface of water are drawn inward, forming drops and beads.

Add – Solute, solution, solvent, pH, heat capacity

Properties of Water

• Adhesion is an attraction between molecules of different substances.

- Example: Water clinging to paper towel.• Capillary action is one of the forces that

draws water out of the roots of a plant and up into its stems and leaves.

(Cohesion holds the column of water

together as it rises)

Bell Work

Select 3 words off of your word wall On the bottom of your word wall- Define the word by DRAWING the

meaning of the word Example:

+ + = Cohesion

Why is water so important to agriculture?

At least 75% of animal body mass is water

Plants contain 70-80% water Transports nutrients and

wastes

Why is water so important to agriculture?

Dissolves compounds -- “Universal Solvent” the liquid in which a solute is

dissolved to form a solution.Solute – the minor component

in a solution, dissolved in the solvent

Why is water so important to agriculture?

Regulates body temperature in animals

Provides structure for plants

E. Summarize the importance of water in agriculture.

What is this?

E. Summarize the importance of water in agriculture.

E. Summarize the importance of water in agriculture.

How much milk does she produce daily?

80-100 pounds per day 8 pounds per gallon

E. Summarize the importance of water in agriculture.

How much WATER does a milk cow drink daily?

2 gallons of water to produce 1 gallon of milk

Remember… 80-120 pounds per day

8 pounds per day

20-30 gallons

F. Identify the function of the four major macromolecules.

Macromolecules= A Very Large Molecule – made up of smaller organic molecules.Remember…

Molecules are structures that are made when atoms are joined by a covalent bond.

Vs.

F. Identify the function of the four major macromolecules.

4 Classes of Macromolecules

Carbohydrates

Proteins

Lipids

Nucleic Acids

Carbohydrates

Provide energy Three Types

Monosaccharides Disaccharides Polysaccharides

CarbohydratesMonosaccharaides

simple SUGAR contain C6H12O6

GLUCOSE, FRUCTOSE, AND GALACTOSE

CarbohydratesDisaccharides

double SUGAR contain two RINGS SUCROSE and LACTOSE

CarbohydratesPolysaccharides

complex CARBOHYDRATES made of RINGS of SUGAR STARCH, CELLULOSE, and

GLYCOGEN

Proteins

STRUCTURE and FUNCTION Made of H, O, C, N

Structure of Proteins

Amino Acids – building BLOCKS20 different kinds – all have the same

elements but in different amounts Polypeptides – chains of AMINO ACIDS

Joined by peptide bonds Proteins – chains of POLYPEPTIDES Used to make SKIN, HAIR, MUSCLE,

ORGANS, etc.

Carbon Atoms Chemical

Bonds

ProteinBeef

Lipids

FATTY molecules used to store ENERGY Made of long chains of H & C followed

by COOH Do not DISSOLVE in WATER Lipids have less OXYGEN than

carbohydrates Examples of Lipids are: FATS, OILS,

AND WAXES

Nucleic Acids

Store INFORMATION that controls CELL activities

Made of a PHOSPHATE a SUGAR, and a BASE.

Examples of Nucleic Acids are: DNA and RNA

Enzymes

Cells use enzymes to speed up chemical reactions that take place in cells.

Enzymes must collide with enough energy to break bonds creating a chemical reactions.

Chemical reactions create energy.

Bell Work-Charades!

Select 2 words off of your word wall Select a partner to work with “Act” out the words you’ve selected to

your partner until they guess Remember Charade Rules

– No Talking– No spelling the words (sign language)

Molecule Structure

Protein

Nucleic AcidLipids

Michelangelo E-Moment

1. When you hear the word “JUMP” you will proceed to the front of the classroom in an orderly manner to get enough gumdrops and toothpicks to create a model of an atom.

2. Think carefully about what you will need. What questions are there?

3. JUMP

Be sure to cover all the basic points about enzymes:Enzymes are biological catalysts that speed up the chemical reactions of the cell.

Enzymes are proteins. Enzymatic reactions occur faster and at lower temperatures because

enzymes lower the activation energy for that chemical reaction. Enzymes are never consumed or used up during the reaction. They can

do their job over and over again. Enzymes are highly specific for just one substrate.  The enzyme has an

active site with a unique 3-D shape into which this substrate must fit.   Enzymes catalyze both the forward and the reverse of the same

reaction. Enzymes can be denatured by temperatures and pH levels outside the

optimal range for that particular enzyme. Enzymes are truly amazing proteins that play a vital role inside every

living cell.  Please don't leave this out of your curriculum!