DEFINITIONS:
Every cell has a salt concentration of 0.9% (0.9 grams of salt (NaCl) per 100 milliliters of water.
If the cell is placed in a solution of 0.9% salt the solution is said to be ISOTONIC. No change in cell size.
If a cell is placed in a solution of water (0% or any solution with less than 0.9% salt) the solution is said to be HYPOTONIC. The cell salt will attract water and the cell will burst or lyse.
If a cell is placed in a solution of any concentration of salt greater than 0.9% - the solution is said to be HYPERTONIC and the cell will shrink or crenate.
Provides protection and support for plant cell..
Plasma membrane or cell membrane is a lipid bilayer composed of proteins and cholesterol. It regulates what passes in and out of cells; cell-to-cell recognition.
Cytoskeleton is a network of protein fibers and tubules. It provides structural support and cell movement.
Flagella or cilia are cell extensions with a 9+2 arrangement. Provide motility or moving fluids over surfaces.
INTERNAL STRUCTURES.
The Endoplasmic Reticulum or ER is a network of internal membranes. Forms compartments and vesicles; modifies and transports proteins; synthesizes carbohydrates and lipids.
Rough ER is covered with ribosomes. Synthesis of membrane proteins, secretory proteins, hydrolytic enzymes; formation of transport vesicles.
Smooth ER is smooth with no ribosomes. Involved with lipid synthesis; carbohydrate metabolism in the liver; and calcium ion storage.
Ribosomes are small, complex assemblies of protein and RNA; often bound to rough ER. Ribosomes are the sites of protein synthesis.
Nucleus is bounded by a double membrane; site of chromosomes; control center of the cell.
Chromatin or chromosomes are strands of DNA; sites of hereditary information.
Nucleolus is the site within the nucleus of rRNA synthesis. The nucleolus is the site of synthesis and assembly of ribosomes.Remember the cell has rRNA (ribosomal RNA); mRNA (messenger RNA); and tRNA (transfer RNA); All forms involved with ribosomes in making protein.).
Golgi apparatus are stacks of flattened vesicles; package proteins for use in or out of the cell.
Lysosomes are membranous sacs containing digestive enzymes. They digest and destroy various moledules and maybe even the cell in which they are present.
Mitochondria are bacterialike elements with inner membrane highly folded. The powerhouses of the cell where ATP made.
Chloroplasts are bacterialike elements with inner membrane forming sacs containing chlorophyll; found only in platn cells and algae. Sites of photosynthesis in plant cells and algae.
Remember the area of the cell between the nucleus and the plasma membrane is called the cytoplasm.
The nucleoid region of the prokaryotic cell contains the cell's DNA.
Under the microscope, plant cells have cell walls and membrane-bound organelles.
The nucleus of a eukaryotic cell contains DNA.
Long fibers of DNA and protein are called chromatin.
During cell reproduction, chromatin coils up into structures called chromosomes.
Bacteria that are unable to survive in the presence of oxygen are called strict anaerobes.
Go on to next lecture which will complete the review for TEST 1.