Cells Cells Three Subdivisions 1 Animal Subdivisions Continued
Cells
Cells Three Subdivisions 1. Animal
Subdivisions Continued 2. Plant
Subdivisions Continued 3. Bacterial
Cell- Basic structural unit of life 1. 2. 3. 4. Small sacs composed mostly of water. The Cell’s membrane is made from a Phospholipid bilayer. This membrane is Semi-permeable (allowing something to pass in or out of the cell and blocking other materials, protecting the cell. ) Cells are 90% fluid which consists of amino acids, proteins glucose and numerous other materials.
Cell Theory. Schwaan and Schleiden 1. 2. 3. The cell is the basic unit of life. All organisms are made of cells. All cells arise from previous cells (not spontaneous generation).
Cell Types 1. Prokaryotes- Cells without a nucleus a. No membrane bound organelles b. Circular DNA found in cytoplasm c. Have a cell wall d. Small in size e. Primitive cells-evolved early (MYA)
Cell Types 1. Eukaryotes- cells with a nucleus bound in a membrane. a. Has many membrane bound organelles. b. DNA, found in nucleus c. Only plants and algae have a cell wall. d. Larger in size. e. Found in multicellular plants and animals.
Organelles of Cells Various functions of cells occur in specialized structures called organelles. The chief organelles and their functions are as follows:
Plasma (cell) membrane Thin, 2 layered film that surrounds the entire cell. (Lipid bilayer. ) a. Found in all cells. b. It is Semi-permeable regulating what enters and leaves the cell. c. This means that it permits the passage or transport of certain materials into and out of the cell, preventing transport of other materials. d. Function: Protection, information, and nutrients in, waste out.
Cytoplasm The fluid-like material inside the plasma membrane and out side the nucleus of the cell. a. Various organelles are present in the cytoplasm and many biochemical processes occur in it. b. The area between cell membrane and nucleus. Contains mainly water and organelles.
Nucleus
Nucleus The nucleus is the most obvious organelle in any eukaryotic cell. The nucleus acts like the brain of the cell. Within the nucleus is the DNA responsible for providing the cell with its unique characteristics.
Ribosomes-Protein synthesis 1. 2. 3. 4. 5. Large numbers of ribosomes in the cell, which may be free in the cytoplasm or attached to the surface of the ER. Site of protein synthesis. RNA is translated into proteins here. Large numbers are found throughout the cell. Some float freely in cytoplasm, others are attached to ER. Very Small in size.
Mitochondrion
Mitochondrion Sites of aerobic respiration. a. Most ATP of the cell is made in the mitochondria. b. Major energy production center in the cell. c. This organelle changes food energy into chemical energy. d. Made of 2 layers (outer and inner which has many folds. )
Golgi Complex/apparatus
Golgi Complex/apparatus Membrane bound channels in which materials are synthesized or packaged. a. Flattened stack of membranes. b. Modifies and packages molecules into small membrane bound sacs called vesicles. c. Vesicles are then moved around the cell or even exported outside of the cell.
Lysosomes (Suicide sacs) These structures contain digestive enzymes which take part in the digestion of food materials. They are small membrane bound structures which digest waste materials inside the cell. Only found in animal cells.
Vacuoles
Vacuoles These are spaces in the cytoplasm enclosed by a membrane. They contain water and other materials. a. Many one celled organisms have food vacuoles in which ingested food is stored and digested. b. Contractile vacuoles pump excess water into and out of the cell.
Cell Wall Prokaryotic cells and plant cells both have a rigid cell wall made up of polysaccharides. The cell wall provides and maintains the shape of these cells and serves a a protective barrier.
Chloroplasts
Chloroplasts. Chloroplasts are specialized organelles found in all higher plant cells. These organelles contain the plant cell's chlorophyll, hence provide the green color. They have a double outer membrane. Within the stroma are other membrane structures - the thylakoids and grana (singular = granum) where photosynthesis takes place. – A. Changes light energy into chemical energy – B. Only found in plants and other photosynthetic organisms.
Relationships of Organelles Explain two relationships of organelles in the cell.
Compare and Contrast: Compare how plants and animals obtain fuel/food. Compare how do plants and animals obtain gasses. Compare how plants and animals excrete waste.
- Slides: 26