1. CH 3 Eukaryotic Cell Structure
Photo Credit: © Quest/Science Photo Library/Photo Researchers, Inc.

2. Eukaryotic Cell Structures
Structures within a eukaryotic cell that perform important cellular functions are known as organelles.
Cell biologists divide the eukaryotic cell into two major parts: the nucleus and the cytoplasm.
The Cytoplasm is the portion of the cell outside the nucleus.

3. Eukaryotic Cell Structures
Plant Cell
Nucleolus
Nucleus
Smooth endoplasmic reticulum
Nuclear envelope
Ribosome (free)
Rough endoplasmic reticulum
Ribosome (attached)
Cell wall
Golgi apparatus
Cell membrane
Chloroplast
Mitochondrion
Vacuole

4. Eukaryotic Cell Structures
Animal Cell
Smooth endoplasmic reticulum
Nucleolus
Nucleus
Ribosome (free)
Nuclear envelope
Cell membrane
Rough endoplasmic reticulum
Ribosome (attached)
Centrioles
Golgi apparatus
Mitochondrion

5. Comparing the Cell to a Factory

6. Organelles
Specialized structures

7. Cytoplasm Portion of the cell outside the nucleus
Consists mostly of water

8. Nucleus
Main Office
Contains nearly all the cell’s DNA & w/ coded instructions for making proteins & other important molecules

9. The Nucleus Chromatin Nuclear envelope Nucleolus Nuclear pores Nucleus
The nucleus controls most cell processes and contains the hereditary information of DNA. The DNA combines with protein to form chromatin, which is found throughout the nucleus. The small, dense region in the nucleus is the nucleolus.
Nuclear pores

10. Nucleus Nuclear Envelope Surrounds the nucleus
Composed of two membranes
Allows messages to enter & leave the main office

11. Nucleus Chromatin Granular material seen in the nucleus
Consists of DNA bound to protein
Condenses to form chromosomes when a cell divides

12. Nucleus Nucleolus Small, dense region in the nuclei
Where assembly of ribosomes begins

13. Ribosomes Small machine in the factory
Proteins are assembled on the ribosomes
Small particles of RNA and protein are found throughout the cytoplasm

14. Endoplasmic Reticulum (ER)
The site where lipid components of the cell membrane are assembled, along w/ proteins & other materials that are exported from the cell
There are 2 types of ER:

15. 1. Rough Endoplasmic Reticulum
Rough ER
Portion of ER involved in the synthesis of proteins
Named b/c ribosomes attach to it
Newly made proteins leave these ribsomes & are inserted into the rough ER, for chemical modification

16. 2. Smooth Endoplasmic Reticulum
Contains enzymes that perform specialized tasks

17. Golgi Apparatus Customization Shop – finishing touches & then shipped
Modifies, sorts, & packages proteins & other materials from the ER for storage in the cell or secretion outside the cell

18. Lysosomes Clean up crew, removes “junk”
Small organelles filled w/ enzymes
Functions include digestion or breakdown of carbohydrates, lipids & proteins

19. Vacuoles Storage center
Sac-like structure that stores water, salts, proteins & carbohydrates

20. Vacuoles
In many plant cells there is a single, large central vacuole filled with liquid.
Vacuole

21. Vacuoles
Contractile vacuole
Vacuoles are also found in some unicellular organisms and in some animals.
The paramecium contains a contractile vacuole that pumps excess water out of the cell.

22. Mitochondria & Chloroplasts
Power plant
Organelles that convert chemical energy stored in food into compounds that are more convenient for the cell to use
Chloroplasts
Solar power plant
Organelles that capture the energy from sunlight & convert it into chemical energy in a process called photosynthesis

23. Mitochondria & Chloroplasts

24. Cytoskeleton Support beams
Network of protein filaments that helps the cell to maintain its shape
Also involved in movement
The cytoskeleton is made up of:
microfilaments
microtubules

25. Copyright Pearson Prentice Hall
Cytoskeleton
Cytoskeleton
Cell membrane
Endoplasmic reticulum
Microtubule
The cytoskeleton is a network of protein filaments that helps the cell to maintain its shape and is involved in many forms of cell movement. Microtubules are part of the cytoskeleton that help maintain cell shape.
Microfilament
Ribosomes
Mitochondrion
Copyright Pearson Prentice Hall

26. Cell Organelle Interactive
Cytoskeleton
Centrioles are located near the nucleus and help to organize cell division.
Cell Organelle Interactive
Plant and Animal Model Interactive

27. The Cell

28. Eukaryotic vs. Prokaryotic
Has a nucleus
Organelles to carry out specialized functions
Flagella or cilia
Single celled organism
Lacks a nucleus & other compartments
Can not carry out many specialized functions
Flagella

29. Comparison of Plant and Animal Cells
Plant has:
Chloroplast
Cell Wall
Regular/Box-like shape
Large Central Vacuole
Animal Cell has:
Centrioles
Irregular shape
Small vacuoles called vesicles

30. END OF SECTION