Introduction to Biology: Basics of Chemistry and Cells

1. Topic: • The Introduction of Biology • Defining of life • Classification of living things • Ecosystem and human interferences • Basic chemistry, the chemistry of organic molecules • Darwin evolutions • History of cells • Cells structures and functions • Photosynthesis and cellular respirations

2. BASIC CHEMISTRY

3. Element – a substance that cannot be broken down to other substances by any chemicals means Exp : FE (needed for any forms of life) I ( required only by certain sp.) Compound - groups of two or more elements that are bonded together Types of bonding between compounds: Covalent compounds happen when the atoms share the electrons Ionic compounds happen when electrons are donated from one atom to another. The elements Hydrogen (H) and oxygen (O) exist as gases –the most abundant compound on earth (H2O) Examples of compounds: Only molecule containing two or more elements, such as water (H2O), carbon dioxide (CO2) and methane (CH4).

4. Living organism??? Are composed of matter (occupied space and has mass) A definition of "matter" that is based upon its physical and chemical structure is: matter is made up of atoms and molecules.

5. The Structure of an Atom Atoms are the basis for everything in the universe. Three basic parts: • _________ = "-" negative charge • _________ = "+" positive charge • _________ = neutral (a charge of zero) The thing that makes each element different = # electrons, protons &neutrons. Protons and neutrons always in the center of atom (the nucleus). The electrons are found whizzing around nucleus in areas called orbitals. If charge of entire atom is "0", there equal numbers of electrons and protons. A neutron walked into a bar and  asked how much for a drink.  The bartender replied,  "for you, no charge."  - Jaime – Internet Chemistry Jokes CHEMISTRY OF LIFE

6. Chemical Bonding and Electron Valences The electrons in an atom are located at different energy levels. The electrons in the highest energy level are called valence electrons. Number of valence electrons govern an atom’s bonding behavior. The max number of valence electrons is 8…a full valence shell. There is a 2-8-8 rule for these elements. Atoms are much more stable, or less reactive, with a full valence shell. This can be achieved one of two ways: - ________ bond - ________ bond By moving electrons, the two atoms become linked. This is known as chemical bonding.

7. Chemical Bonds Ionic (donate) Covalent (share) Attractions between ions of opposite charge - Exp NaCl Two atoms share one or more pairs of outer-shell electrons - form a molecule - Exp H2

8. WATER H2O Exists in liquid (water), solid (ice cube, snow), and gaseous (water vapour) states Essential for all living things. “Universal solvent” because many substances dissolve in it. Unique properties result from how H2O molecules interact with each other. Bonding electrons are shared unequally by the hydrogen and oxygen atoms: - partial negative charge (-) forms at ______ end - positive charge (+) forms at _______end When the electrons in a covalent bond are not equally shared, the molecule is ________.

9. Physical States Vapor

10. Cohesion • The attraction water to itself – H bonds

11. Adhesion • The attraction of water to other surfaces/substances

12. Surface Tension • Interaction between hydrogen bonding and the earth’s gravitational pull

13. Capillary Action • “Wettable” surfaces cause a film of water to partially pull away from other water molecules and cling to the surface. • Capillary action is important in soil and plant/water relations.

14. Solutions Solutions are mixtures in which one substance is dissolved in another. Solutions have two parts: solute and solvent The ________ is the substance that is dissolved. The ________ is the substance that does the dissolving (remember water, the ‘universal solvent’?) ____________ - A measure of how much of a given substance will dissolve in a liquid. A substance that does not dissolve in water is called insoluble. Example:Oil is insoluble in water. A substance that does dissolve in water is called soluble. Example: Sugar is soluble in water.

15. Osmosis • Osmosis is the net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane • The water moves from the area of higher solute concentration to the area of lower solute concentration until equilibrium is reached

16. Osmosis

17. pH: Alkalinity/Acidity • The measurement of the H+ ions found in that particular substance • The scale goes from 0 to 14 • 7 is neutral • Below 7 is acidic • Above 7 is alkaline (or basic) • One pH unit represents a ten-fold change in H+ concentration

18. The pH Scale

20. What are 4 major macromolecules found in living organism? Macromolecules ?? - large, organic molecules that make up living things. Carbohydrates, lipids, proteins, nucleic acids:1. Carbohydrates: Are Molecule composed of carbon, hydrogen, and oxygen, and they include sugars and starches.2. Lipids: Are non polar molecule that includes fats, oils, and cholesterol.3. Proteins: A Proteins is a polymer made of monomers called amino acids.4. Nucleic Acids: Are polymer that are made up of monomers called nucleotides.