1. -Chapter 7 –The Cell Answer the “Key Concept” Questions for Each Section. Period 1 Lab (Quiz) date = Wednesday November 12 Test Date= Friday November 14 Quiz Vocab:Secs: 1-3 Period 4 Lab (Quiz) date = Thursday November 13 Test Date= Monday November 17 Period 7 Lab (Quiz) date = Friday November 14 Test Date= Monday November 17

2. Overview: The Fundamental Units of Life All organisms are made of cells The cell is the simplest collection of matter that can live Cell structure is correlated to cellular function All cells are related by their descent from earlier cells – New cells produced from existing cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

3. Eukaryotic cells have internal membranes that compartmentalize their functions The basic unit of every organism is one of two types of cells: prokaryotic or eukaryotic Bacteria = prokaryotic Protists, fungi, animals, and plants all consist of eukaryotic cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

4. Comparing Prokaryotic and Eukaryotic Cells Basic features of all cells: –Plasma membrane –Semifluid substance called cytosol (cytoplasm) –Chromosomes (carry genes) –Ribosomes (make proteins) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

5. Prokaryotic cells are characterized by having –No nucleus –DNA in an unbound region called the nucleoid –No membrane-bound organelles –Cytoplasm bound by the plasma membrane Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

6. Fig. 6-6 Fimbriae Nucleoid Ribosomes Plasma membrane Cell wall Capsule Flagella Bacterial chromosome (a)A typical rod- shaped bacterium (b)A thin section through the bacterium Bacillus coagulans (TEM) 0.5 µm

7. Eukaryotic cells are characterized by having –DNA in a nucleus that is bounded by a membranous nuclear envelope –Membrane-bound organelles –Cytoplasm in the region between the plasma membrane and nucleus Eukaryotic cells are generally much larger than prokaryotic cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

8. Fig. 6-9a ENDOPLASMIC RETICULUM (ER) Smooth ERRough ER Flagellum Centrosome CYTOSKELETON: Microfilaments Intermediate filaments Microtubules Microvilli Peroxisome Mitochondrion Lysosome Golgi apparatus Ribosomes Plasma membrane Nuclear envelope Nucleolus Chromatin NUCLEUS

9. Fig. 6-9b NUCLEUS Nuclear envelope Nucleolus Chromatin Rough endoplasmic reticulum Smooth endoplasmic reticulum Ribosomes Central vacuole Microfilaments Intermediate filaments Microtubules CYTO- SKELETON Chloroplast Plasmodesmata Wall of adjacent cell Cell wall Plasma membrane Peroxisome Mitochondrion Golgi apparatus

10. Inside The Cell What’s inside the cell? What does the cell need to sustain life? How are Cells different? Are cells independent or dependent or both? Are there levels of organization?

11. Characteristics of Cell Cells come in all types of shapes and sizes Spheres, Cubes and bricks Spikes, bulges and extensions Cells come in all different sizes Bacteria are about 1 micrometer Human egg cell is about 1 millimeter

12. Inside the Cell Cytoplasm – What is it? It’s the substance inside the cell. What’s it contain? 70 percent is water 30 percent is: Proteins, fats, carbohydrates, nucleic acids and ions. The exact composition varies among different cells. Why?

13. The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomes The nucleus contains most of the DNA in a eukaryotic cell Ribosomes use the information from the DNA to make proteins Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

14. The Nucleus: Information Central The nucleus contains most of the cell’s genes and is usually the most conspicuous organelle The nuclear envelope encloses the nucleus, separating it from the cytoplasm The nuclear membrane is a double membrane; each membrane consists of a lipid bilayer Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

15. In the nucleus, DNA and proteins form genetic material called chromatin Chromatin condenses to form discrete chromosomes The nucleolus is located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

16. Fig. 6-10 Nucleolus Nucleus Rough ER Nuclear lamina (TEM) Close-up of nuclear envelope 1 µm 0.25 µm Ribosome Pore complex Nuclear pore Outer membrane Inner membrane Nuclear envelope: Chromatin Surface of nuclear envelope Pore complexes (TEM)

17. Ribosomes: Protein Factories Ribosomes are particles made of ribosomal RNA and protein Ribosomes carry out protein synthesis in two locations: –In the cytosol (free ribosomes) –On the outside of the endoplasmic reticulum or the nuclear envelope (bound ribosomes) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

18. Fig. 6-11 Cytosol Endoplasmic reticulum (ER) Free ribosomes Bound ribosomes Large subunit Small subunit Diagram of a ribosome TEM showing ER and ribosomes 0.5 µm

19. The endomembrane system regulates protein traffic and performs metabolic functions in the cell Components of the endomembrane system: –Nuclear envelope –Endoplasmic reticulum –Golgi apparatus –Lysosomes –Vacuoles –Plasma membrane These components are either continuous or connected via transfer by vesicles Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

20. The Endoplasmic Reticulum: Biosynthetic Factory The endoplasmic reticulum (ER) accounts for more than half of the total membrane in many eukaryotic cells The ER membrane is continuous with the nuclear envelope There are two distinct regions of ER: –Smooth ER, which lacks ribosomes –Rough ER, with ribosomes studding its surface Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

21. Fig. 6-12 Smooth ER Rough ER Nuclear envelope Transitional ER Rough ER Smooth ER Transport vesicle Ribosomes Cisternae ER lumen 200 nm

22. Functions of Smooth ER The smooth ER –Synthesizes lipids –Metabolizes carbohydrates –Detoxifies poison –Stores calcium Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

23. Functions of Rough ER The rough ER –Has bound ribosomes, which secrete glycoproteins (proteins covalently bonded to carbohydrates) –Distributes transport vesicles, proteins surrounded by membranes –Is a membrane factory for the cell Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

24. The Golgi apparatus consists of flattened membranous sacs called cisternae Functions of the Golgi apparatus: –Modifies products of the ER –Manufactures certain macromolecules –Sorts and packages materials into transport vesicles The Golgi Apparatus: Shipping and Receiving Center Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

25. Fig. 6-13 cis face (“receiving” side of Golgi apparatus) Cisternae trans face (“shipping” side of Golgi apparatus) TEM of Golgi apparatus 0.1 µm