Cell+Notes

__Cells__ - the basic unit of life.
 * Ch 4 Notes**

A general statement that states:
 * What is the cell Theory?**
 * All living things are made up of cells.
 * Cells are the basic unit of structure and function.
 * Cells come from other cells.

__Robert Hooke -__ First person to see and name cells. Reminded him of the rooms (cells) in a monastery.

__Anton van Leeuwenhoek -__ First person to see LIVING cells.

__ Matthias Schleiden - __ Botanist that stated all plants are composed of cells.

__ Theodor Schwann - __ Zoologist that stated ____ are composed of cells.

__ Rudolf Virchow - __#|Doctor __that stated cells only come from cells.__

__ **How do microscopes** __**#|work__?__** Microscopes use lenses to magnify the object by focusing light or electrons.

A prokaryotic cell does not contain a nucleus or other organelles, while eukaryotic cells do.
 * How are prokaryotic and eukaryotic cells different?**

Cell Membrane – (plasma membrane) - Outer boundary of the cell.

Nucleus – Large organelle near the center of the cell that contains DNA. Controls all cell activity.

Eukaryote (Eukaryotic cell) – Cells with a nucleus and other organelles. Typically larger than Prokaryotes but not always. Found in Plants, Animals, Fungi and Protists.

Prokaryote (Prokaryotic cell) – Cells without a nucleus or most other organelles. Typically smaller than Eukaryotes but not always. Found in Bacteria.

The nucleus controls all cell activity and contains the DNA
 * What is the role of the cell nucleus?**

Cytoplasm – (Cytosol) - Clear jelly-like fluid inside the cell. Maintains shape of cell, transports materials and cushions the cell.

Organelles – Little organs - cell parts that do a specific function.

Nuclear Envelope - double membrane around the nucleus.

Nucleolus – Where ribosomes are made.

Vacuoles store materials, Lysosomes “digest” things for the cell and the Cytoskeleton maintains the shape of the cell and is needed for movement.
 * What are the functions of the vacuoles, lysosomes and the cytoskeleton?**

Vacuole – Empty space within the cell. Used to store toxins and wastes.

Lysosome – Contain digestive enzymes. Used to destroy invaders or broken down cell parts.

Cytoskeleton – The structure and framework of the cell. Used to maintain shape and for locomotion.

Microfilaments – Fine protein "threads" that are part of the cytoskeleton.

Contractile Vacuole - "Pump" excess water out of the cell. (Sump pump of the cell)

Vesicle - Small organelles used to transport materials.

Microtubules – Small protein "tubes" that are part of the cytoskeleton.


 * What organelles help make and transport Proteins?** Proteins are made in the Ribosomes, stored and transported through the ER. The Golgi apparatus modifies them and packages them into Vesicles which carry them out of the cell.;

Ribosomes – Small round organelles that make Proteins. Ribosomes can be found in both Prokaryotic and Eukaryotic cells

Endoplasmic Reticulum (ER) - Series of flattened sacs that act as a cellular highway, storage area for Proteins and a site of Ribosomal attachement.
 * Rough ER - has many attached Ribosomes
 * Smooth ER - has few if any attached Ribosomes

Golgi Apparatus – Processing, Packaging and Excreting organelle. (Fed-Ex of the cell)


 * What are the functions of Chloroplasts and Mitochondria?** Chloroplasts=Photosynthesis, Mitochondria=Cellular Respiration

Plastids – Organelles of plants, double membrane.
 * Chloroplasts - organelles found in plants that contain chlorophyll, responsible for photosynthesis.
 * Chromoplasts - Contain accessory pigments (red, yellow, orange)
 * Leukoplasts - Storage sites for starch.

Mitochondria – Organelle with a double membrane, site of cellular respiration. contains DNA. The powerhouse of the cell.


 * What is the function of the cell membrane?** holds the cell together, controls what enters or leaves the cell.

Cell Wall – Rigid outer protective covering of the cell.

Cell Membrane – flexible outside boundary of the cell, said to be Semi-Permeable. ALL CELLS have a cell membrane.

Selectively Permeable / Semi-Permeable – Ability to allow some substances to pass through but stop others.

Fluid Mosaic Model of the Cell Membrane – Visual representation of the cell membrane, called Fluid because they can flow and change shape, called Mosaic because it is made up of lots of little pieces.
 * Lipid Bilayer - 2 layers of phospholipids
 * Hydrophylic Head - Water loving head
 * Hydrophobic Tails - Water fearing tails