1. Ch 4: A Tour of the Cell
Figure 4.6a

2. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

3. Plasma Membrane
The plasma membrane separates the living cell from its nonliving surroundings.

4. Cell Surfaces
Most cells secrete materials for coats of one kind or another
That are external to the plasma membrane.
Extracellular coats
help protect and support cells
facilitate interactions between cellular neighbors in tissues

5. Plant cells and bacterial cells have cell walls,
Which help protect the cells, maintain their shape, and keep the cells from absorbing too much water.
Animal cells have an extracellular matrix,
Which helps hold cells together in tissues and protects and supports them (not shown).

6. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

7. The Nucleus: Genetic Control of the Cell
The nucleus is the manager of the cell.
Genes in the nucleus store information necessary to produce proteins.
Prokaryotes do not have nuclei.
Their genes (on DNA) are in the nucleoid region

8. Structure and Function of the Nucleus
The nucleus is bordered by a double membrane called the nuclear envelope.
It contains chromatin and a nucleolus.
Chromatin: long strands of DNA and associated proteins. The DNA stores the genetic information (genes).
Nucleolus: assembles ribosomes

9. Ribosomes: Protein Synthesis
Ribosomes are responsible for protein synthesis.

10. How DNA Controls the Cell
DNA controls the cell by transferring its coded information into RNA.
The information in the RNA is used to make proteins.

11. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

12. The Endomembrane System: Manufacturing, Distributing, and Storing Cellular Products
Not found in bacterial cells!

13. The Endoplasmic Reticulum
The endoplasmic reticulum (ER)
Produces an enormous variety of molecules.
Is composed of smooth and rough ER.

14. Smooth ER
The smooth ER lacks the surface ribosomes of rough ER and produces lipids, including steroids.

15. Rough ER
The “roughness” of the rough ER is due to ribosomes that stud the outside of the ER membrane.
The functions of the rough ER include:
Producing two types of membrane proteins
Membrane proteins
Secretory proteins
Producing new membrane

16. Rough ER
The “roughness” of the rough ER is due to ribosomes that stud the outside of the ER membrane.
The functions of the rough ER include:
Producing two types of membrane proteins
Membrane proteins
Secretory proteins
Producing new membrane

17. After the rough ER synthesizes a molecule, it packages the molecule into transport vesicles. These vesicles head off to the Golgi Apparatus…

18. The Golgi Apparatus The Golgi apparatus
Works in partnership with the ER.
Refines, stores, and distributes the chemical products of cells.

19. Lysosomes
A lysosome is a membrane-enclosed sac that contains digestive enzymes to break down macromolecules.

20. Vacuoles Vacuoles are membranous sacs.
Contractile vacuoles of protists get rid of excess water.
Central vacuoles of plants store nutrients, absorb water, contain some pigments or poisons.

21. A review of the endomembrane system
An amazing system that manufactures, distributes, and stores cellular products!

22. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

23. Energy Conversion: Chloroplasts & Mitochondria
Cells require a constant energy supply to do all the work of life.
Not found in bacterial cells!

24. Chloroplasts
Chloroplasts are the sites of photosynthesis, the conversion of light energy to chemical energy.
All little green circles are chloroplasts
Cell walls

25. Mitochondria
Mitochondria are the sites of cellular respiration, which involves the production of ATP from food molecules.

26. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

27. The Cytoskeleton: Cell Shape and Movement
The cytoskeleton consists of a network of fibers.
Also, recently found in bacterial cells!

28. Cytoskeleton Can change cell shape to allow movement
Mechanical support to maintain cell shape

29. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

30. Cilia and Flagella Cilia and flagella are motile appendages.
Not found on most plant cells!

31. Flagella propel the cell in a whiplike motion.
Cilia move in a coordinated back-and-forth motion.

32. Structure Meets Function in a Cell
Plasma Membrane and Cell Surface
Nucleus and Ribosomes
Endomembrane System
Endoplasmic Reticulum (ER)
Golgi Body
Lysosomes
Vacuoles
Energy Conversion: Chloroplasts and Mitochondria
Cytoskeleton
Cilia and Flagella
Plastids

33. Plastids Membrane-bound organelles found only in plants
Amyloplast
stores starch (stained blue with iodine)
All little green circles are chloroplasts
Chromoplast stores pigments
(little orange circles)
Cell walls
Chloroplast performs photosynthesis