Cells and Organelles

1. Cells and Organelles Presented by: Mrs. Carmen Knopke

2. Ten levels of biological systems Adapted from Campbell, Reece & Mitchell, Biology 6th edition, 2002 with permission of Pearson Education, Inc.

3. 5 Characteristics of Living Things Maintains Homeostasis: Keeps a constant internal environment

4. 1) The prokaryotic cell: bacteria2) The Eukaryotic cell: Contain membrane bound organelles

5. The prokaryotic cell

6. Characteristics of Prokaryotes • 1) No membrane bound organelles • 2) Simple and small unicellular organisms • 3) Simple DNA • 4) Reproduce by slitting called Binary fission

8. Azotobacter chroococum 40X, 40X HM

9. Staphylococcus aureus 100X, 40X (enlarged to 100X)

10. Archaebacteria (mixed) 100X

11. Mycobacterium tuberculosis 100X

12. Sarcina lutea 100X Neisseria gonorrhoeae 100X Diplococcus pneumoniae 100X Staphylococcus aureus 100X

13. Bacillus megaterium 100X Corynebacterium diptheriae 100X Clostridium perfringens 100X Shigella dysenteriae 100X

14. Spirillum serpens 100X

15. Spirochaete 100X

16. The eukaryotic cell

17. Bigger and more complex than Prokaryotic Cells2) Contain membrane-bound organelles

18. There are 4 types of eukaryotic cells1) PLANT2) ANIMAL3)FUNGI 4) PROTIST

19. Nucleus Nucleoli Rough endoplasmic reticulum Smooth endoplasmic reticulum Golgi complex Lysosomes Peroxisomes Mitochondria Chloroplasts Ribosomes Major cellular organelles

21. Structure and function Adapted from Campbell, Reece & Mitchell, Biology 6th edition, 2002 with permission of Pearson Education, Inc.

22. Function of the Cell Wall • Protect the intracellular contents • Bestows rigidity • Provides porous medium for circulation and distribution of water, minerals, and other nutrients • Houses specialized molecules that regulate growth and protect plant from disease

24. Location • Surrounds the cell membrane on plant cells Plant Wall Cell Structure

25. Where is this Structure Found in the Body? • Nowhere in living organisms • Only found in the stomach after eating a salad or some other plant matter

26. Function • The membrane is the flexible boundary between the cell and its environment • The plasma membrane allows steady supply of nutrients to come into the cell • Semi-permeable • Allows some molecules to pass through while keeping others out

27. Structure • Phosholipid bilayer • Two layers of phospholipids • Interior: fatty acid tails • Exterior: phospholipid heads • Creates a water-soluble barrier (hydrophilicheads) in the outer surfaces and a water-insoluble in the middle (hydrophobictails)

29. Structure in relation to function • It gives the cell shape by attaching itself to the cytoskeleton. • It forms tissue by attaching itself to the extra-cellular matrix to group cells together. • Help transfer molecules in and out of cell • Accepts chemical signals such as nerve impulses and hormone activity. • Help metabolism (enzyme activity inside the cell) to serve as a defense mechanism for the cell.

30. What cells to find them in • Cell membrane is found in every living cell!

31. Definition • Cytoplasm is a jelly-like material that fills a cell • Consists of cytosol and the all cellular organelles except the nucleus • It is known as the “molecular soup” in which organelles are suspended and held together by the fatty membrane • A common analogy is that it is jello that holds still and suspends all that is in it

32. Structure • The cytoplasm is a jelly like material that is made up of mostly water, mostly clear in color • Because it liquefies when it is shaken or stirred it is more like a gel then a watery substance • Cytoplasm contains cytosol, which is made up of water, salts, organic molecules and many enzymes

33. Structure to Function • Cytoplasm has three main functions, energy, storage, and manufacturing. • Each of the organelles it holds performs a specific cellular function • The cytoplasm is composed of components that benefit the cell and keep the organelles separate from one another • Its many enzymes catalyze reactions in the cytoplasm

34. Cells in Body • Cytoplasm can be found in eukaryotic cells, which are plant cells, and in the prokaryotic cells, which are plant cells • The cytoplasm in animal cells is much larger than that found in the plant cell

35. The Function of the Nucleus • The Nucleus is the control center of the cell; it is able to control process that occur in the cell • The Nucleus holds and duplicates the DNA required for cell division • The Nucleus is where the synthesis of ribonucleic acid (RNA) occurs

36. The Location of the Nucleus • The nucleus is found only all eukaryotic cells • In animal cells, the nucleus is found near the center of the cell. In plant cells the large vacuole pushes it to the side • The nucleus is one of the only organelles visible from a standard microscope

37. Nucleus Location Animal Cell Plant Cell

38. Structure • The Nucleus is usually round in shape • It is surrounded by a nuclear envelope, quite similar to the cell membrane • The nuclear envelope has holes known as nuclear pores

39. Which Cells in the Body Have a Nucleus? • Most cells in the human body have a nucleus • One exception is the blood cell (Erythrocyte) • Because these cells have no nucleus, they have no DNA

40. Cell Power House • Organelle found in most eukaryotic cells • Mitochondria are sometimes described as "cellular power plants" • They convert organic materials into energy in the form of ATP via the process of oxidative phosphorylation • Hence fuel the energy-hungry reactions of life • They take in fuel molecules derived from sugars and fats, harvest the energy in their chemical bonds with the aid of oxygen, and spit out ATP

44. Mitochondria Structure • A mitochondrion contains of: • Outer and inner membranes • It is Composed of phospholipid bilayers and proteins. • The two membranes have different properties. • Due to this membrane organization there are 5 distinct compartments within the mitochondria • The intermembrane space • The cristae space • The matrix

46. Enzymes (Illustration – Eric R. Russell)

47. Relation Between Structure and Function: Matrix • The matrix contains soluble enzymes that catalyze the oxidation of pyruvate and other small organic molecules. • The matrix of the mitochondria also contains the mitochondria's DNA and ribosomes. • Mitochondria replicate their DNA and divide mainly in response to the energy needs of the cell

48. Relation Between Structure and Function: Cristea • Due to the cristae: • Reactions have a greater surface area to take place in. • If the cristae were not there, the inner membrane would be reduced to a single spherical shape, offering a smaller area for these reactions to occur. • With the cristae, the surface area for these proteins is greatly increased, and so are a necessity for the mitochondria to function efficiently.

49. Creating Energy • A dominant role for the mitochondria is the production of ATP • Reflected by the large number of proteins in the inner membrane for this task. • This is done by oxidizing the major products of glycolysis: • pyruvate and NADH

50. Cell Organelles:The Chloroplast Nancy Nguyen George Mavritsakis