1. The Living Cell

2.  “Cell” –Named by Robert Hooke who used microscope to look at cork (1663) –Described by Anton van Leeuwenhoek who designed his own microscope to look at living cells (1676) –“Cell Theory” developed by Schleiden & Schwann (1838)

3. The Living Cell  Cell Theory –All living things are composed of cells –The cell is the fundamental unit of life –All cells arise from previous cells

4. The Living Cell  Cell membrane –Separates the “inside” from the “outside” –Made from a bilayer of phospholipid molecules –Allows certain certain molecules to pass through –Has protein protein receptors to assist other molecules –May be surrounded by a cell wall (in plants)

5. The Living Cell  Nucleus –Present in eukaryotes –Controls the cell’s heredity and chemistry –Contains DNA in chromosome pairs –“mitosis” results in 2 daughter cells with same DNA as original cell –“meiosis” results in the production of egg and sperm cells with ½ DNA as original cell

6. The Living Cell  Energy organelles –Chloroplasts Contains chlorophyll which absorbs energy from sunlight Site of photosynthesis Found in green plants –Mitochondria Site of respiration Release energy from food by metabolism Found in both plants and animals

7. The Living Cell  Photosynthesis vs. Respiration –Photosynthesis produces energy rich glucose –CO 2 + H 2 O C 6 H 12 O 6 + O 2 (carbon dioxide + water = glucose + oxygen) –Respiration releases energy from glucose –C 6 H 12 O 6 + O 2 CO 2 + H 2 O + energy sunlight

8. The Living Cell  Energy generation in cell  Glycolysis is 1 st step – breaks down glucose and produces ATP  Followed by Respiration, in presence of oxygen Fermentation, in absence of oxygen

9. The Living Cell  Other organelles –Endoplasmic reticulum Smooth Rough –Ribosomes –Nucleoli –Golgi apparatus –Lysosomes –Vesicles and vacuoles –Cytoskeleton –Centrioles

10. The Living Cell  Differences between plant and animal cells –Plant Cell wall Large central vacuole Chloroplasts –Animal None of the above Centrioles