Chemical Basis of LifeUnit A-2

Elements are recycled!Everything, including people are made up of elements that recycle throughout the universe. Everything in the universe including oceans, mountains and stars recycle important elements . These elements form compounds which form parts of our body!

Oceans- Recycle O2 and Carbon.

Mountians- Recycle Carbon, metals

Stars- Recycle Helium and Hydrogen.

Water is Life Giving.Water is an agent of giving life. Without it life could not exist.

Raging Water! Water is also an agent of change and

destruction.

Water shaped the grand canyon! Water can be powerful! A flood is a good example of the power of water.

Water Helps Us Everyday.Too cool us as sweat. And to keep us

hydrated in sports.

Why Can Water Do All These Amazing Things?

Structural formula Chemical Formula

Terms:

Atom: Basic Unit of Matter.Element: Pure substance that cannot be

broken down and is made of only one type of atom.

Isotope: Atoms of the same element that have different numbers of neutrons.

Terms (cont)Molecule: Formed when two or more atoms join

together. They can be the same atom or different atoms.

Compound: A compound is formed when two or more different atoms join together chemically (CH4, CO2). Molecules can be compounds but compounds can’t be molecules.

Polarity: Uneven distribution of electrons between hydrogen and oxygen. Oxygen carries a large negative charge that attracts electrons more than the small positive hydrogen's.

Important BondsCovalent Bond- Share Electrons

Ionic bonds- Donate Electrons

Hydrogen bond- hydrogen's attract oppositely charged polar molecules.

Water Has Superpowers!!Power # 1: It can stick to itself! This is called

cohesion. Cohesion creates surface tension. Surface Tension: allows a water strider to

float on top of the water.

Water Has Superpowers!!Power #2: Water can stick to other substances. This is

called adhesion. This is what you see in a water glass:

Water Has Superpowers!!Power #3: Water has a high specific heat. This means

that water can absorb a lot of heat energy and its temperature will not change rapidly. This allows water to absorb the sun’s heat and keep earth cool. Without water earth would be too hot to live on!

Mixtures, Solutions and SuspensionsSolutions- Mixture with even distribution.

Mixture-Two or more compounds that are mixed together but not chemically combined. (Salt water )

Suspensions- mixture of water and un-dissolved material. (sand and water)

Water’s Final Superpower: Universal Solvent

Water can dissolve mostly anything!When water is a solvent (dissolving

something) that dissolves a solute (the thing being dissolved) we call that an Aqueous Solution or Aqueous Mixture. Ex: Salt water

A Simple Rearrangement, Addition or Loss of Atoms Can Make a Big

Difference!Methane- A cow burp!

Benzene–This can kill you!

What Allows for These Interesting Rearrangements?

All atoms can form different amounts of bonds and attach in unique ways!

Carbon can have 4 bonds.Oxygen can have 2 bonds.Hydrogen can have 1 bond. Other elements that are important to life are

Phosphorus (P), Sulfur (S) and Nitrogen (N).All these elements form Covalent Bonds

with each other.

EnzymesEnzymes speed up reactions in our body to

complete various functions.How long would it take for us to digest food

without enzymes?

Saliva- DigestionStomach Enzymes-

Digestion

In our cells-Speed up processes for making human energy

EnzymesEnzymes are like the “matchmakers” of

biology:They speed up things that would have taken

forever otherwise. Like a relationship… Bob and Sue were

destined to date but it was taking forever! So John (Bob and Sue’s friend) helped speed it up and get them together.

John was acting like an enzyme!

Enzymes Enzymes are catalysts- They speed up chemical

reactions.They are made of Protein.Speed up reactions by lowering Activation

Energy. Our body wouldn’t be able to function if this energy wasn’t lowered.

Enzymes Enzymes have a specific shape. They are not used up when they are in a

chemical reaction.However they can be shut off/effected by:

Temperature changes. Your body enzymes are good at 98.6 degrees Fahrenheit.

pH changes.Concentration Levels.

Enzymes Enzyme names usually end in -ase. Enzymes work on a substrate. Enzymes can

add or break down substrates.