The Cell Cytology History of the Cell Two

The Cell: Cytology

History of the Cell – Two Ages

1. Cell Theory Age: 3 Scientists

Robert Hooke: 1 st Microscope/the cell

Anton van Leeuwenhoek: animal cells

Marcello Malpighi: “Father Microscopy” medicinal use of microscopes

2. Age of Microbiology – 3 scientists

Joseph Lister – proposed aseptic surgery

Robert Koch: germ theory – microbes cause disease

Louis Pasteur: vaccines, Pasteurization, disproved spontaneous generation

Spontaneous Generation: living organisms arise from non-living entities

Cytology: the study of the cell

Cell Theory – 3 postulates 1. All cells come from pre-existing cells 2. Cells are the basic unit of life 3. All living organisms are composed of cells

Two Types of Cells 1. Prokaryotic Cells: small simple cells -lack a nucleus -lack complex organelles -contain ribosomes 2. Eukaryotic Cells: complex cells -membrane bound nucleus -DNA in nucleus -complex organelles

Plant Cells 2. Cell Wall (Rigid) 1. Chloroplasts 3. Central Vacuole 4. Rectangular Shape

Animal Cells 2. Cell Membrane 1. No Chloroplasts 3. Many small vacuoles 4. Many Shapes

Cellular Levels of Organization Cell Tissue Organ System Organism

Cell Organelles: Cell’s “organs” - Cells are fully functioning systems

1. Cell Membrane: FX: regulates what enters/leaves the cell

2. Nucleus: FX: A. store DNA B. control center of the cell 2 A: Nucleolus: makes ribosomes

3. Cytoplasm: gel like substance in the cell FX: site of all cell activities

4. Endoplasmic Reticulum Two Types 1. Rough ER: makes and transport proteins (has ribosomes) 2. Smooth ER: lipid synthesis

5. Ribosomes: small organelles FX: produce proteins -500, 000 per cell

6. Mitochondria: rod shaped; double membrane FX: Produce energy molecules – adenosine triphosphate (ATP) “Powerhouse” of the cell

7. Golgi Apparatus: flat sacs FX: Package, sort, and transport cellular products

8. Lysosome: FX: to break down foreign contaminants Filled with enzymes

9. Microtubules FX: support the cell shape Cytoskeleton

10. Centrioles: Cylindrical structures FX: assist in cell division