Cells!

1. Cells! http://koning.ecsu.ctstateu.edu/cell/cell.html

2. Early Microscopes/Cell Discoveries Mid 1600’s: scientists use microscopes to observe living things. 1665, Englishman Robert Hooke • Used an early compound microscope • Nonliving thin slice of cork, a plant material. • Made of thousands of tiny, empty chambers • Called them “cells”. Holland: Anton van Leeuwenhoek • examined pond water, saw living things! • his own mouth • Discovered what we know today as “bacteria”

3. Early Microscopes/Cell Discoveries In 1838, German botanist Matthias Schleiden • All plants are made of cells. The next year, 1839 German biologist Theodor Schwann • All animals were made of cells. In 1855, German physician Rudolf Virchow • New cells could be produced only from the division of existing cells,

4. Cell Theory • 1) • 2) • 3) Why a theory??

5. Definition of Cell A cell is the smallest unit that is capable of performing life functions.

6. Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

7. Two Types of Cells Prokaryotic Eukaryotic

8. Prokaryotic • Do not have structures surrounded by membranes • Few internal structures • One-celled organisms • Ex: Bacteria http://library.thinkquest.org/C004535/prokaryotic_cells.html

9. ALL LIVING THINGS ARE MADE OF CELLS Cells __________ a NUCLEUS AND ORGANELLES surroundedby MEMBRANES = _________________ Cells __________ a _____________ OR ORGANELLES surroundedby _______________ = ________________ Bacterial Cell http://www.earthlife.net/prokaryotes/welcome.html http://summit.k12.co.us/schools/shs/computer/tkelley/types.html

10. Eukaryotic • Contain organelles surrounded by membranes • Have DNA in nucleus • Most living organisms Plant Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html

11. “Typical” Animal Cell http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

12. “Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif

13. Cell Parts Organelles -A minute structure within a plant or animal cell that has a particular job or function. -Cells are like factories

14. Structure and Function STRUCTURE= How it is built/constructed FUNCTION= What it DOES and How it WORKS. How does its Structure dictate it’s Function?

15. Cytoplasm • Portion of cell outside of nucleus • Holds the organelles • Gel-like mixture • Surrounded by cell membrane • “cyto”= • “plasm” =

16. NUCLEUS Largest organelle in animal cells Image from: http://www.mccc.edu/~chorba/celldiagram.htm

17. NUCLEUS • Surrounded by NUCLEAR ENVELOPE (also called NUCLEAR MEMBRANE) DOUBLE MEMBRANE Image from: http://www.agen.ufl.edu/~chyn/age2062/lect/lect_06/5_11.GIF

18. NUCLEUS NUCLEAR PORES Openings to allow molecules to move in and out of nucleus Image from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookCELL2.html

19. WHAT DOES IT DO? Contains genetic material (DNA) DNA is scrunched up as CHROMOSOMES in dividing cells DNA is spread out as CHROMATINin non-dividing cells

20. WHAT DOES IT DO? Control center of cell Image from: Genetic code tells the cell’s parts what to do, gives instructions. Image from: http://web.jjay.cuny.edu/~acarpi/NSC/12-dna.htm

21. NUCLEOLUS Image from: http://lifesci.rutgers.edu/~babiarz/histo/cell/nuc3L.jpg Dark spot in nucleus = __________ Makes _______________

22. NUCLEUS NUCLEOLUS • Surrounded by ______________ MEMBRANE called the NUCLEAR __________________ • ___________ CENTER OF CELL • Nuclear ___________ allow molecules in & out • CONTAINS CELL’S GENETIC MATERIAL (_______) • Dark spot = NUCLEOLUS makes ___________________ (RNA) DNA is scrunched up as ______________ in dividing cells. DNA is spread out as ________________ in non-dividing cells.

23. Review: Nucleus • Directs cell activities • Separated from cytoplasm by nuclear membrane • Contains genetic material – DNA • Double membrane • Nickname: “The Control Center” • Function: holds the DNA • Parts: • Nucleolus (noo KLEE uh lus) • Dark spot in middle of nucleus that helps make ribosomes

25. Organelles That Store, Clean Up, and Support • Vacuoles • Lysosomes • Cystoskeleton

26. Vacuoles: • The cells ‘storage units’, • Store:

27. VACUOLES Large in plant cells Image from: http://www.biologycorner.com/resources/plant_cell.gif http://library.thinkquest.org/3564/Cells/cell93.gif

28. VACUOLES • Storage space for WATER, salts, proteins (enzymes), carbohydrates, and waste • Small in ANIMAL CELLS • NO VACUOLES in bacteria

29. Vacuoles in plants • In many plant cells, there is a single, large central vacuole filled with liquid. • Increases their ability to support heavy structures such as leaves and flowers. -It’s what makes lettuce crisp • When no water, it wilts

30. Vacuoles and Vesicles Nearly all eukaryotic cells contain smaller membrane-enclosed structures called _____________. Vesicles are used to store and move materials between cell organelles, as well as to and from the cell surface.

31. VACUOLES VESICLES Storage space for: _______________ Huge in __________cells , small in _____________ cells, Not in _________________ _____________________ are used to store and move materials between organelles

32. Lysosomes: • the ‘cleanup crews’ of the cell • Small organelles filled with _________________. • Breaks down “food:” lipids, proteins, and carbohydrates, into small molecules to be used by rest of cell. • Also breaks down “old” organelles.

33. LYSOSOMES • Can remove junk too Image modified from: http://www.people.virginia.edu/~rjh9u/lysosome.html

34. LYSOSOMES Found in Animal cells and sometimes in Plant cells, although rare Sac containing _________________________ FUNCTION: Breaks down __________, _________________, ____________

35. The Cytoskeleton: • Complex network of protein filaments

36. The Cytoskeleton: • Support, maintains cell shape • Transports materials within the cell, like a conveyor belt • Helps cells move • Made of proteins • Microfilaments and microtubules are two of the principal protein filaments that make up the cytoskeleton. • Microtubules are polymers, circular chains of a protein known as tubulin.

37. Microfilaments • Threadlike structures made up of a protein called actin. • Extensive networks • Produce a tough, flexible framework that supports the cell. • Help cells move. • Microfilament assembly and disassembly is responsible for the cytoplasmic movements that allow cells, such as amoebas, to crawl along surfaces

38. Microtubules • Hollow structures made up of proteins known as tubulins. • Play critical roles in maintaining cell shape.

39. Green---Nuclei Purple----Microfilaments Yellow----Microtubules

40. Microtubules • Important in cell division • In animal cells, structures known as centrioles are also formed from tubulins. • Centriolesare located near the nucleus and help to organize cell division. • Centrioles are not found in plant cells. • Microtubules also help to build projections from the cell surface • cilia and flagella • enable cells to swim rapidly through liquids.

41. CENTRIOLES-organize cell division in animals cells Help separate/sort chromosomes

42. Organelles That Store, Clean Up, and Support What are the functions of vacuoles, lysosomes, and the cytoskeleton? Vacuoles store materials like water, salts, proteins, and carbohydrates. Lysosomes break down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell. They are also involved in breaking down organelles that have outlived their usefulness. The cytoskeleton helps the cell maintain its shape and is also involved in movement.

43. Organelles That Build Proteins • Ribosomes • Endoplasmic Reticulum (ER) • Golgi Apparatus

44. Organelles That Build Proteins Protein Purpose/Function: • Control rate of reactions • Regulate cell processes (Enzymes in lysosomes) • Form cellular structures (Cytoskeleton) • Transport materials in and out of cell (Cell Membrane proteins) • Help fight disease • Made of H O N C Cells need to build new molecules all the time, especially proteins Big part of the cell is devoted to their ______________________ and ____________________________. • Because proteins carry out so many of the essential functions of living things

45. Ribosomes Made of small particles of ________________ and ______________ found throughout the cytoplasm in all cells and on Rough ER Produce/Assemble proteins by following coded instructions from DNA. Proteins targeted for export to the cell membrane or to specilazed locations within the cell, complete their assembly on ribosomes BOUND to the RoughEndoplasmic Reticulum

46. RIBOSOMES • Protein factory for cell • Join amino acids to make polypeptide chains which make up proteins.  Image by: RIedell Image from: http://www.ust.hk/roundtable/hi-tech.series/1_b1.jpg

47. RIBOSOMES Can be __________________ or __________ to Rough ER MADE OF ______________ & ________ FUNCTION: _____________________ Found in _____________ types of cells

48. Endoplasmic Reticulum Internal membrane system • In Eukaryotic cells Assemble: Assemble some ___________________and other materials that are exported from the cell.

49. Rough Endoplasmic Reticulum , ER Involved in the synthesis of proteins Given this name because of the ribosomes found on its surface Newly made proteins leave these ribosomes and are inserted into the rough ER, where they may be chemically modified.

50. Smooth Endoplasmic Reticulum, ER The other portion of the ER Ribosomes are not found on its surface…so Smooth Contains collections of enzymes that perform specialized tasks • S • D