Cell Structure & Function

1. Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html

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

3. Cell Theory Cell Theory 1. All organisms are composed of cells. 2. Cells are basic unit of structure and function in living things 3. Cells arise only from pre-existing (OLD) cells.

4. Two Types of Cells Prokaryotic Eukaryotic

5. Prokaryote cells are smaller and simpler • Commonly known as bacteria • 10-100 microns in size • Single-celled(unicellular) or • Filamentous (strings of single cells)

6. These are prokaryote E. coli bacteria on the head of a steel pin.

7. Prokaryotes • Are generally smaller than eukaryotic cells • Have no nucleus • Carry out all of life’s processes • Ex: bacteria

8. Eukaryotes • Are generally larger and more complex than prokaryotes • Contain dozens of membrane bound structures that are specialized • Nucleus separates DNA from rest of cell

9. Exploring the Cell There are 3 major types of microscopes • 1) Light Microscope • Magnifies 40 – 1,000 times depending on objective being used • Used to magnify objects that light can pass through. • Uses slides

10. 2) Scanning Electron Microscope • Uses electrons to illuminate objects (3D view) • Can magnify from 30,000 to 9 million times • Mostly large institutions have them • Costly to own and maintain • Can only be used to look at dead specimens

12. Transmission Electron Microscope • TEM- thin slices need to be made to have clear images, images are 2-D • Useful for studying internal structures

13. Organelles are membrane-bound cell parts • Mini “organs” that have unique structures and functions • Located in cytoplasm

14. Cell Structures • Cell membrane • delicate lipid and protein skin around cytoplasm • found in all cells

15. Nucleus • a membrane-bound sac evolved to store the cell’s chromosomes(DNA) • has pores: holes

16. Nucleolus • inside nucleus • location of ribosome factory • made or RNA

17. mitochondrion • makes the cell’s energy • the more energy the cell needs, the more mitochondria it has

18. Ribosomes • build proteins from amino acids in cytoplasm • may be free-floating, or • may be attached to ER • made of RNA

19. Endoplasmic reticulum • may be smooth: builds lipids and carbohydrates • may be rough: stores proteins made by attached ribosomes

20. Golgi Complex • takes in sacs of raw material from ER • sends out sacs containing finished cell products

21. Lysosomes • sacs filled with digestiveenzymes • digest worn out cell parts • digest food absorbed by cell

22. Centrioles • pair of bundled tubes • organize cell division

23. Cytoskeleton • made of microtubules • found throughout cytoplasm • gives shape to cell & moves organelles around inside.

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

25. Structures found in plant cells • Cell wall • very strong • made of cellulose • protects cell from bursting • glued to other cells next door

26. Vacuole • huge water-filled sac • keeps cell pressurized • stores starch

27. Chloroplasts • filled with chlorophyll • turn solar energy into food energy

28. How are plant and animal cells different?