1. All organisms are composed of one or more cells. It can be unicellular or multicellular.
2. The cell is the basic unit of structure and organization of organisms
3. All cells come from preexisting cells. A cell divides to form two same cells.
Organelles- membrane-bound stuctures with particular functions within eukaryotic cells.
Prokaryotes- unicellular organisms, lacks internal membrane-bound structures.
Eukaryotes- unicellular or multicellular organisms, which contain a true nucleus and membrane-bound organelles.
Nucleus- in eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA.
Plasma membrane- the flexible boundary between the cell and its environment, that allos materials such as water and nutrients to enter and waste products to leave.
Composed of the phospholipid bilayer and the embedded proteins.
Phospholipid- lipid with an attached phosphate group.
The phospholipid bilayer- The head of the phospholipid is polar, the water is polar as well, so it attracts the water from the watery environment (hydrophilic). They form a water-soluble surface.
However, the fatty acid tails is nonpolar, thus they avoid water. The fatty acid tails form the interior of the membrane, as a hydrophobic layer. Water-soluble molecules will not easily move through the membrane because they are stopped by this water-insoluble layer.
Fluid mosaic model- structural model of the plasma membrane where molecules are free to move sideways within a lipid layer.
Transport proteins- proteins that span the plasma membrane creating a selectively permeable membrane that regulates which molecules enter and leave a cell.
Selecitve permeability- feature of the plasma membrane that maintains homeostasis within a cell by allowing some molecules into the cell while keeping others out.
Cell wall- fairly rigid structure located outside the plasma membrane of plants, fungi, most bacteria, and some protists; provides support...