1. Saturday, October 10, 2015 1 The Cell Packet #11

2. Saturday, October 10, 2015 2 Cytology The study of cells. There are two basic types – Prokaryotic cells – Eukaryotic cells

3. Saturday, October 10, 2015 3 The Discovery Cells discovered by Robert Hooke in 1665 – However the subcellular structures could not be seen--the organelles It wasn’t until the 1950’s, with the invention of the electron microscope that cell biology really took off

4. Saturday, October 10, 2015 4 Organelles Isolation Can be isolated by a process called cell fractionation – Taking cells apart and separating the major organelles so that their individual function can be isolated – Centrifuge Is the instrument that is used to fractionize cells Spins fast as much as 80,000 revolutions per minute and apply forces on particles up to 500,000 times the force of gravity

5. Saturday, October 10, 2015 5

6. Saturday, October 10, 2015 6 Organelle Isolation II Micromanipulation – Another technique for the removal of parts of the cell – Can also insert material into a living cell – Done while looking through a microscope In-Vitro Fertilization In-Vivo Fertilization Cell Cultures** – Isolate one type of cell and you grow it in large numbers--bacteria for example

7. Saturday, October 10, 2015 7 Cell Theory Observations and conclusions from various scientists – All living things are composed of cells – Cells are the basic units of structure and function in living things – All cells come from preexisting cells

8. Saturday, October 10, 2015 8

9. Saturday, October 10, 2015 9 Prokaryotic versus Eukaryotic Prokaryotic – No nuclear membrane No nucleus Lack membrane bound organelles – No chromosomes--circular strands of DNA – May contain chlorophyll but not chloroplasts – Small Ribosomes – Cell wall is present** – No mitosis or meiosis occurs

10. Saturday, October 10, 2015 10 Prokaryotic versus Eukaryotic II Eukaryotic Cells – Nuclear membrane is present Nucleus is present Membrane bound organelles – Chlorophyll when present, contained in chloroplasts – Ribosomes are larger – Cell wall is present in some – Mitosis and meiosis occurs

11. Saturday, October 10, 2015 11

12. Saturday, October 10, 2015 12 Eukaryotic Cells Most organisms are composed of eukaryotic cells. There are two basic types – Plant cells – Animal cells

13. Saturday, October 10, 2015 13 Plant Cells Cell wall that contains cellulose Large vacuole filled with cell sap Larger than animal cells Shape** Cilia and flagella absent in higher plants

14. Saturday, October 10, 2015 14 Animal Cells No cellulose cell wall-only membrane Some vacuoles but usually small and numerous Cytoplasm throughout the cell Nucleus anywhere in cytoplasm by often central Cilia common in higher animals

15. Saturday, October 10, 2015 15 Cell Specialization {Animal Cell} Cells are often uniquely suited to perform a particular function within the organism – Nerve Cells – Muscle Cells – Rods and Cones in the eye – Sex cells – Determined by complex processes of turning on and off genes.

16. Saturday, October 10, 2015 16

17. Saturday, October 10, 2015 17

18. Saturday, October 10, 2015 18 Plant Cell vs. Animal Cell Similarities – Both Eukaryotic Cells – Have membrane bound organelles Differences – Plant cells are “generally” larger than animal cells – Plant cells have a cell wall of cellulose Adds stability and protection to the plant cell – Plant cells have vacuoles That are used as space fillers Fulfils digestive functions in plants--similar to lysosomes that are also found in plant cells. – Animal cells have centrioles

19. Saturday, October 10, 2015 19 Cell Structure and Function I Chromatin – The complex of DNA and histome proteins which make up chromosomes in eukaryotic cells Chromosomes – Long threadlike association of genes composed of chromatin and found inside the nucleus of the cell Nucleolus – The region of the eukaryotic nucleus that engaged in ribosome synthesis

20. Cell Structure and Function II Nucleus Structure – Contains a eukaryotic cell’s genetic library Nucleus Function – In eukaryotic cells, this is a membrane bound organelle that contains the cell’s genetic material – Acts as the control center for the cell – Produce ribosomes and RNA* – Play an essential role in cell division Nuclear Envelope – Surrounds the nucleus – Contains nuclear pores Allow things in and out of the nucleus Saturday, October 10, 2015 20

21. Saturday, October 10, 2015 21

22. Saturday, October 10, 2015 22 Cell Structure and Function II Rough or Smooth? Rough Endoplasmic Reticulum – Functions in the synthesis and transport of proteins – This is where we find ribosomes Smooth Endoplasmic Reticulum – Functions in the synthesis and transport of lipids – There are no bound organelles—that is why they look so smooth Ribosomes – Cytoplasmic organelle that is the site for protein synthesis – Small complex particles consisting of proteins and RNA

23. Saturday, October 10, 2015 23

24. Saturday, October 10, 2015 24

25. Saturday, October 10, 2015 25 Cell Structure and Function III Golgi Apparatus – Stack of membranous sacs – Packages and distributes lipids and proteins that form in the ER – If we have time we will have a closer look at this process – Something inportant—know the ends and structure Cis—entry; Trans—exit—People always forget this – Vesicles enter and leave here Lysosome – Contains digestive enzymes that degrades the cell and other malfunctioning organelles

26. Saturday, October 10, 2015 26

27. Saturday, October 10, 2015 27 Cell Structure and Function IV Peroxisome – Contains enzymes that carry out redox reactions and is key in detoxification of drunks Mitochondria – This is where we produce our energy—AKA ATP – We’ll get all up in the Kreb’s cycle soon

28. Saturday, October 10, 2015 28

29. Saturday, October 10, 2015 29 For Biology 1 Honors Only Cells are composed of filaments – Microtubules – Microfilaments – Intermediate filaments Details to come in AP Biology

30. Saturday, October 10, 2015 30 Other Important Features in the Cell Chloroplasts – In plants—used in photosynthesis – We’ll get to know this process later as well

31. Saturday, October 10, 2015 31

32. Saturday, October 10, 2015 32 Cell to Cell Connections Tight Junctions Gap Junctions Desomeres – Details to come in AP Biology

33. Saturday, October 10, 2015 33

34. Saturday, October 10, 2015 34

35. Saturday, October 10, 2015 35 Components of the Cell Membrane Microfilaments, Microtubules and Intermediate filaments—we have already touched—but what else is there? Glycoproteins Carbohydrates Cholesterol – Used in rigidity and fluidity of the membrane Peripheral Protein (small) and Integral (big) proteins—useful in hormonal signals—later IT IS IMPORTANT TO KNOW WHAT EVERYTIHNG LOOKS LIKE AND WHERE THEY ARE IN THE CELL MEMBRANE

36. Saturday, October 10, 2015 36

37. Saturday, October 10, 2015 37 Diffusion Ok, now that we know some of the ways proteins enter organelles (from earlier), let’s have a closer look at some mechanisms in which how molecules and proteins are transported across the membranes of these organelles. Firstly let’s define the word Diffusion – The three types of diffusion Regular Diffusion—we travel down the concentration gradient—no energy is required Facilitated Diffusion—we travel down the concentration gradient using a protein molecule--no energy is required Active Transport—flow of molecules against the concentration gradient with the use of a protein molecule--ATP (energy) is required.

38. Saturday, October 10, 2015 38

39. Saturday, October 10, 2015 39 Diffusion II Which of the two previous are considered passive transport and why? – Regular and facilitated—reason is because there is no use of energy Examples – Active transport—transport of proteins through nuclear pores

40. Saturday, October 10, 2015 40 Diffusion III Migration of substances from regions or high concentration to regions of low concentration. – Occurs in our lungs--CO2 out O2 in Regular Diffusion

41. Saturday, October 10, 2015 41 Diffusion IV Special Diffusion Osmosis – Notes from Previous Lecture Solution –Solvent--Major –Solute--minor – Transfer of a liquid solvent through a semi permeable membrane that does not allow dissolved solids (solutes) to pass. – Osmosis refers only to the transfer of the solvent. – High Concentration to an area of low concentration.

42. Saturday, October 10, 2015 42

43. Saturday, October 10, 2015 43