1. Biology-The Science of Life
Mr. Evans
Biology-The Science of Life

2. What is Life????

3. Characteristics of Life

4. Characteristics of Life

5. Characteristics of Life

6. The Hierarchy of Life Life goes from the Simple to the Complex…..
Let’s see how many we can figure out together

7. The element of Carbon is the basis for all life as we know it
The Chemistry of Life
The element of Carbon is the basis for all life as we know it
CHONSP

8. Ions and Molecules
Electrons orbiting atoms interact to form IONS, and the IONS join together to form MOLECULES
This is the bases for how all organic compounds form!

9. But elements in nature are rarely found this way
Isotopes
Neutral elements have equal numbers of protons, neutrons, and electrons
But elements in nature are rarely found this way
An element with a different number of neutrons than protons is called an ISOTOPE

10. Chemical Bonds Transferred Partially Shared Mostly Shared Fully Shared
Ionic Polar Covalent Nonpolar Covalent Diatomic

11. Water All life on Earth needs WATER to survive
Water provides a solvent for the chemistry of life to happen
Without a solvent, living things would be a pile of powder
Imagine a thick soup with all the water boiled away…..

12. The Water Molecule Water is a DIPOLE molecule
Has a slightly positive end and a slightly negative end
This leads to a rare ability to form HYDROGEN BONDS

13. Unique Properties of Water
Water is LESS Dense as a Solid than as a liquid. This is why ice floats! This is not a normal thing.
It takes a relatively large amount of heat to raise the temperature of water, and vice versa
Water can dissolve just about anything given enough time

14. Unique Properties of Water
Cohesion – Water will cling to itself
Adhesion – Water will cling to other stuff too

15. Solution Chemistry
Ions and compounds dissolved in the water can effect its properties (ELECTROLYTES)
Temperature and pressure of water can also effect its chemistry
Warmer water will execute chemical reactions faster
The conditions of the water are VITAL to allow the chemistry of life to happen

16. Acids and Bases
One of the most important factors is the acidity or basicity of the water
Acidity is measures by the H+ ion concentration
Basicity is measured by the OH- ion concentration

17. Acids and Bases VIDEO

18. Conclusion The chemistry of life in insanely complex
Everything in the mix effects everything else
Biochemistry happens in a cascading chain, and each step is required before the next can happen
We don’t have it all figured out yet….but new discoveries are being made everyday

19. Activity : What if water…..
Didn’t dissolve stuff?
Wasn’t less dense as a solid than a liquid?
Wasn’t attracted to itself?
Had a low heat capacity?