Cellular Structure Unit 3

1. Cellular StructureUnit 3 The cell is the smallest functional unit of life.

2. Unit Concepts • The cell theory • Prokaryotes versus Eukaryotes • Eukaryotic organelles • Cell Diversity

3. Our understanding of cells can be summed up by the Cell Theory. • All living things are composed of one or more cells • Cells are the basic unit of structure and function. • All cells arise from existing cells.

4. All living things are composed • of one or more cells. • Some creatures are single celled –unicellular. • Some creatures exist in colonies with other unicellular creatures – colonial. • Some creatures exist with many cells that communicate, and share the responsibilities required for life – multicellular.

5. 2. Cells are the basic unit of structure and function. • Cells extracted from an organism can be caused to grow and function normally. • Parts of cells only function when they are combined with the other parts of a cell. • Cells are the smallest “living” structure.

6. 3. All cell arise from existing cells. • In 1668, Francisco Redi used a rotting meat “model” to disprove spontaneous generation. • In 1855, Rudolph Virchow, a physician studying disease, reasoned that cells arise only from other cells. Sick people make other people sick! • Around 1861, Louis Pasteur proved beyond a doubt that biogenesis occurs. His research led to the process of Pasteurization used to can food and bottle milk.

7. Unit Concepts • The cell theory • Prokaryotes versus Eukaryotes • Eukaryotic organelles • Cell Diversity

8. All cells have 5 important features in common. • A cell membrane regulates what enters and leaves the cell. • Within the cell membrane, a thick gooey material known as cytoplasm suspends the organelles and contains the necessary building blocks for chemical reactions.. • A network of microtubules and microfilaments called the cytoskeleton provides for support and shape changing ability. • Nucleic acidsstore genetic information and regulate a cells activities. • Ribosomes read the nucleic acids to order amino acids into the necessary proteins.

9. Prokaryoticcells are more simple than Eukaryotic cells. • All prokaryotic cells are in Kingdom Eubacteria or Archaebacteria. • Prokaryotic cells contain the 5 essential cell parts and usually a cell wall. • Cell membrane • Cytoskeleton • Cytoplasm • Ribosomes • Nucleic Acids • Prokaryotic cells were the first to appear on Earth and continue to be the simplest cells.

10. Eukaryoticcells are more specialized than prokaryotes. • All eukaryotic cells are in Kingdom Protista, Fungi, Plantae, or Animalia. • Eukaryotes have all 5 essential cell parts as well as: • Nucleus • Membrane bound organelles • It is believed that Eukaryotic cells may have formed from the combining of simpler prokaryotic cells. These remnants of bacteria life are now integral parts of our cells (mitochondria and chloroplasts).

11. Prokaryotic cell vs. Eukaryotic cell

12. Unit Concepts • The cell theory • Prokaryotes versus Eukaryotes • Eukaryotic organelles • Cell Diversity

13. Eukaryoticcells have a defined nucleus and many additional cell parts called organelles.

14. The nucleusdirects the activities of a eukaryotic cell. • Chromosomes made of DNA and proteins are located here. • Chromosomes are divided into genes coding for each trait (eye color, hitchhiker’s thumb, etc.). • RNA (copies of the genes) leaves the nucleus through the nuclear pores.

15. There are many organelles within Eukaryotic cells that are formed or surrounded by phospholipid bilayer. • Endoplasmic Reticulum • Golgi Apparatus • Vesicles • Lysosomes • Specialized Organelles

16. The phospholipids naturally arrange themselves into cells (spheres) due to its polar / non-polar interactions with water.

17. The Endoplasmic reticulum (ER) is a system of tubes within the cell, that help to transport materials. • Rough ER is studded • with ribosomes. • B. RNA travels from the nucleus to the ribosomes(site of protein synthesis)then continues through the ER. • Newly formed proteins are pinched off the ER and form a vesicle. • A Vesicleis used to transport materials out of the cell, or to a different location.

18. The Golgi Apparatus is used for processing, packaging and secreting materials. • Proteins may arrive here after their creation in the ER. • Proteins may be processed in a way that alters their shape and functionality. • Proteins leave the Golgi in vesicles that may fuse with the cell membrane when materials need to exit the cell.

19. Lysosomes are sacs filled with digestive enzymes. • Formed when digestive enzymes are pinched off the Golgi. • Site of food digestion in the cell. • May be used to break down old, or non-functional cell parts.

20. Proteins being processed by the Golgi Apparatus

21. ER, Golgi, Vesicles, Lysosomes and Cell Membrane are all have a phospholipid bilayer outer membrane.

22. Mitochondriaare the power generators of both plant and animal cells. • Cells that require a lot of energy, like muscle cells, have thousands of Mitochondria. • Mitochondria are folded many times internally for extra surface area. • Convert carbohydrates into a useable form of energy called ATP.

23. Chloroplastsperform photosynthesis in photoautotrophic organisms. They have a tremendous amount of internal surface area. This allows for the maximum number of energy producing reactions.

24. Since mitochondria carry their own DNA and ribosomes, Lynn Margulis proposed that they may have once been independent organisms. EndosymbioticTheory

25. Unit Concepts • The cell theory (I) • Prokaryotes versus Eukaryotes (E) • Eukaryotic organelles (E) • Cell Diversity (C)

26. Members of each kingdom can be identified by the presence of 4 common characteristics.

27. Plant cells have three distinguishing characteristics that are different than animal cells. • Organelles called chloroplasts use light energy to produce carbohydrates from CO2 and H2O. • Plants have a cell wall composed of cellulose. • Plants have large central vacuoles that are involved in storage of water, proteins and toxins.