Cells

__Cells__ **Lab #1** which relates to cells is Diffusion and Osmosis. The purpose of this lab was to investigate the processes of diffusion and osmosis in a model membrane system and to investigate the effect of solute concentration on water potential as it relates to living plant tissues. Diffusion is the random movement of molecules from an area of higher concentration of those molecules to a lower concentration and osmosis is the diffusion of water through a selective permeable membrane from higher water potential to lower water potential. This water potential is the measure of free energy of H2O in a solution. In diffusion, Hydrophobic molecules such as hydrocarbons, CO2, and oxygen can ass the membrane with ease. Hydrophillic molecules pass through the membrne very slowly. Transport proteins are also required to channel water molecules, other certain molecules, and atomic ions through the membrane. Tonicity also has many different effeects on a cell. In a hypertonic solution, the cell looses H2O to the environment and the cell shrivels. In a hypotonic environment the cell gains H20 from the environment and the cell will swell and burst. If the cell has osmoregulation then the cell can control the balance of H2O.

__Summary:__

Cells make up every living object. All cells have cell membranes, cytoplasm, ribosomes, and nucleic acids. The two types of cells are prokaryotic and eukaryotic. Prokaryotic cells only have the characteristics mentioned before. Eukaryotic cells have those characteristics plus a membrane bound nucleus, and many other organelles. Cells use diffusion to trasport molecules across their membranes. When they are transporting water this is called osmosis. Cells reproduce through mitosis and meiosis. Cells recognize each other with glycocalyx. They signal each other through chemical signaling(endocrine system) and electical signaling(nervous system).

//**ORGANELLES**//


 * **Nucleus**- controls gene expression; mediates DNA replication; site for genetic transcription; controls metabolism; controls protein sythesis; coordinates cell division
 * **Cell Membrane**- a thin membrane (a double layer of lipids) enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions (like sodium or potassium or calcium) in and out of the cell
 * **Cell Wall**- the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the and provides these cells with structural support and protection, and also acts as a filtering mechanism
 * **Centrioles**- cylindrical structures that are composed of groupings of microtubules and found in animal cells that play a role in cell division
 * **Cytoplasm**- a thick liquid residing between the cell membrane holding organelles, except for the nucleus
 * **Rough Endoplasmic Reticulum**- covered in ribosomes; makes secretory proteins; separates secretory proteins from proteins produced by free ribosomes; produces transport vesicles to wrap secretory proteins; assembles new membrane; ER membrane is transferred in transport vesicles
 * **Smooth Endoplasmic Reticulum**- without ribosomes; sythesis of lipids; metabolism of carbohydrates; detoxification of drugs/poisons; produces steroids; stores calcium ions that trugger different responses when released
 * **Golgi Apparatus**- modifies macromolecules like lipids and to ship them to other places in the cell; acts as the "post office" of the cell; plays a vital role in cell secretion; transport vesicles carry macromolecules from the ER to the golgi apparatus
 * **Ribosome**- carries out protein sythesis and faciliates the specific coupling of tRNA anticodons with mRNA codons during protein sythesis; bound to the rough ER, the nuclear envelope, or suspended in the cytosol
 * **Vacuole**- a storage bubble found in both animal and plant cells; stores food and nutrients the cell might need to survive along with waste to protect the rest of the cell from contamination; stores a large amount of water in plant cells; supports the structure of plants; keeps little disturbances such as lipids and fats out of the cell
 * **Chloroplast**- captures energy from light with thylakoids; converts carbon dioxide and water into organic molecules
 * **Mitochondria**- provides energy for the cell; location for the production of ATP
 * **Flagella**- form of locomotion for cells; made up of microtubules; move in a snake-like motion to propell the cell
 * **Cilia**- form of locomotion for cells; made up of microtubules; found all around the cell; move like oars in a back and forth motion
 * **Chromosomes**- usually in the form of chromatin; contains genetic information; composed of DNA; thicken for cellular division; set number per species
 * **Nuclear Membrane**- surrounds nucleus; composed of two layers; numerous openings for nuclear traffic
 * **Nucleolus**- spherical shape; visible when cell is not dividing; contains RNA for protein manufacture
 * **Cytoskeleton**- composed of mircotubules; supports cell and provides shape; aids movement of materials in and out of cells
 * **Lysosome**- digestive "plant" for proteins, lipids, and carbohydrates; transports undigested material to cell membrane for removal

//**DIFFERENCES BEWTEEN MEIOSIS AND MITOSIS**//

//**THE CELL CYCLE**//

More Vocab...
 * //THE STAGES OF MITOSIS//**

**Passive Transport**: does not require energy **Diffusion**: is the random movement of molecules from an area of higher concentration of those molecules to a lower concentration **Osmosis**: is the diffusion of water through a selective permeable membrane from higher water potential to lower water potential **Facillitated Diffusion**: is the diffusion of large molecules through a transport protein **Active Transport**: movement of substances agaist its concentration gradient…. Uses energy (ATP) **Phospholipid Bilayer**: is the two lipid bilayers made of a hydrophilic head and a hydrophililc tail…. amphipathic **Hydrophillic**: likes water **Hydrophobic**: fears water **Glycocalyx**: sugar groups important for cell to cell recognition **Intergral Membrane Proteins**: embedded into the membrane **Peripheral Membrane Proteins**: lie on the surface of the membranes **Cholesterol**: important to membrane fluidity **Selectively Permeable**: membranes that only allow some substances to enter or exit the cell

Signaling Endocrine System: control center of body. Uses chemical signaling. Chemical Signaling: binding of chemicals to portein receptors. Synaptic Signaling: release of neurotrasmitter into a synapse. Paracrine Signaling: chemical released from one cell, influences its close neighbors. Hormonal Signaling: chemical(hormone) released into blood stream and influences cells far away. Steroid Hormones: affect transcription of DNA to initiate long-term changes in the target cell. Peptide Hormones: affect enzyme activity to initiate a short-term change in the target cell.