See Below For Notes
TEST: Friday August 20, 2004
Covers : 2-1 and 2-3
8/17/04 Chemical Bonding
The main types of chemical bonds are
Ionic and Covalent
Ionic Bonds
Formed when one or more electrons are transferred from one atom atom to another.
Ionic Bonding
Ions positively and negatively charged atoms.
Ionic Bonding forms between a metal and a non metal.
Ionic Bonding
Metals are found on the left side of the periodic table.
Non Metals are found on the right side of the periodic table.
Covalent Bonds
Covalent bonds form when electrons are shared between atoms.
Example: H2O
Covalent Bonds
Covalent Bonds occur between two non-metals.
Van der Waals Forces
A bond that forms when molecules are close together.
There is a slight attraction that can develop between the oppositely charged regions of nearby molecules.
4 Organic Compounds
Found in all living things:
Carbohydrates
Lipids
Nucleic Acids
Proteins
8/18/04 Properties of Water
Polarity
A water molecule is polar because there is an uneven distribution of electrons between the oxygen and the hydrogen atoms.
Hydrogen Bonds
The attraction between the hydrogen atom of one molecule and the oxygen atom on another water molecule.
Cohesion
Attraction between molecules of the same substance.
Adhesion
An attraction between molecules of different substances.
Solutions
Mixture of two or more substances in which the molecules of the substances are evenly distributed.
Made of Solute and Solvents
Suspension
Suspensions are mixtures of water and non-dissolved materials.
Acids and Bases
Acid any compound that forms Hydrogen ions in a solution. H+
Bases A compound that produces hydroxide ions. OH-
Buffers
Weak acids or bases that can react with strong acids.
pH Scale
A measurement scale that indicates the concentration of H+ ions in a solution.
Ranges form 0 to 14.
8/13/04 The Nature of Matter
Atom the basic unit of matter
The subatomic particles that make up the atom are the:
Protons +
Neutrons
Electrons
Element
A pure substance that consists entirely of one type of atom.
Isotopes
Atoms of the same element with different numbers of neutrons.
Radioactive elements isotopes that have an unstable nucleus. Give off radiation. Have many important scientific and practical uses.
Compounds
A chemical compound is a substance formed by the chemical combination of two or more elements in definite proportions.
Example: NaCl
Third Test
What is a Cell?
A cell is the basic unit of all forms of life.
Are cells found in all living things?
Yes!
8/23/04 Cell Theory
1. All living things are composed of cells
2. Cells are the basic units of structure and function and living things.
3. New cells come from pre-existing cells.
Basic Cell Structures
Cell membrane a thin, flexible barrier around the cell.
Nucleus a large structure that contains the cells genetic materials and controls the cells activities.
Cytoplasm the jelly-like material inside the cell.
Two Types of Cells
Prokaryotes - The earliest type of cell.
- No Nucleus
- smaller and simpler than other cells
- no organelles
- example: Bacteria
Two Types of Cells
Eukaryotes
- Have a Nucleus
- Have organelles
- larger than prokaryotic cells
8/30/04
Cell Wall Used to provide support and protection for the cell. Found in plant cells.
Chromatin
The granular material visible within the nucleus.
Chromosomes
Chromosomes are found in a cell when it is dividing.
It is condensed chromatin.
Nucleolus
A small, dense region found in the nuclei.
Nuclear envelope a double-membrane layer that surrounds the nucleus.
Cytoskeleton
A network of protein filaments that helps the cell to (1) maintain its shape and (2) with movement.
Cytoskeleton
Mircotubules hallow tubes of protein. They maintain cell shape and also serve as "tracks" along which organelles move.
Microfilaments long, thin fibers that function in the movement and support of the cell.
9/2/04
Organelles in the Cytoplasm
Ribosomes small particles of RNA and protein used to make proteins.
Endoplasmic Reticulum An internal membrane system where proteins are modified.
Golgi Apparatus
Modifies Proteins that are made by the Endoplasmic Reticulum by attaching carbohydrates and lipids.
Lysosomes
Small organelles filled with enzymes.
Break down old structures that have seen their best days.
Vacuoles
Saclike structures that store materials.
Chloroplasts
Found in plants and some other organisms.
Mitochondria
Release energy from stored food molecules.
Sept. 9, 2004
Cell Quiz and Lab - Meet in McArthur's Room
Sept. 10, 2004
Cell Transport
Cell membrane Regulates what enters and leaves the cell.
Lipid Bilayer A double layered sheet that forms the membrane.
Selectively Permeable Membrane
Some substances can pass across and others cannot.
Cell Membrane
(Pg. 184)
The membrane also contains proteins that form channels and pumps to move materials across the membrane.
Concentration
A solution is the mass of solute in a given volume of solution, or mass/volume.
Diffusion
Molecules moving from areas of high concentration to areas of low concentration.
Diffusion
Diffusion causes many substances to move across a cell membrane but does not require the cell to use energy.
Osmosis
The diffusion of water through a selectively permeable membrane.
Facilitated Diffusion
Also called passive transport
The movement of molecules with the concentration gradient.
Requires No Energy!
Active Transport
The material moves from an area of lower concentration to an area of greater concentration.
