Biology-The Science of Life Mr. Evans 8-16-2018 Biology-The Science of Life

What is Life????

Characteristics of Life

Characteristics of Life

Characteristics of Life

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

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

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!

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

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

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…..

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

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

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

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

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

Acids and Bases VIDEO

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

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?