1. Cell Structure and Function
By Mrs. Leesa Peery

2. Outline Cell Theory Cell Size Prokaryotic Cells Eukaryotic Cells
Organelles
Nucleus
Endomembrane System
Cytoskeleton
Centrioles, Cilia, and Flagella

3. Cell Theory
Cell theory states all organisms are composed of cells and that cells come only from preexisting cells.
One of the unifying concepts of biology.

4. Cell Size Most cells are much smaller than one millimeter.
Some are as small as one micrometer.

5. Small cells are likely to have an adequate surface area for exchanging wastes for nutrients.
Cells that specialize in absorption have modifications that greatly increase the surface area per volume of the cell.

6. Organism Sizes

7. Prokaryotic Cells Lack a membrane-bound nucleus. Structurally simple.
Can be divided into two domains:
Bacteria
Archaea

8. Bacteria
Three Shapes
Bacillus (rod)
Coccus (spherical)
Spirilla (spiral)
Archaea
Live in extreme habitats.

9. Prokaryotic Cells

10. Prokaryotic Cells Cell Envelopes
Include plasma membrane, cell wall, and glycocalyx (layer of polysaccharides outside cell wall).
Capsule – Well-organized layer.
Form internal pouches (mesosomes).

11. Prokaryotic Cells Cytoplasm
Cytoplasm is a semifluid solution encapsulated by plasma membrane.
Inclusion Bodies - Stored granules of various substances.

12. Prokaryotic Cells
Appendages
Flagella
Fimbriae
Sex Pili

13. Eukaryotic Cells Members of domain Eukarya.
Contain membrane-bounded nucleus.
Contain specialized organelles.
Contain plasma membrane.

14. Eukaryotic Cell Plasma Membrane

15. Organelles
Organelles of endomembrane system communicate with one another.
Basically self-sufficient
Compartmentalization allows eukaryotic cells to be larger than prokaryotic cells.

16. Animal Cell Anatomy

17. Plant Cell Anatomy

18. Nucleus Contains chromatin in semifluid nucleoplasm.
Condense to form chromosomes.
Separated from cytoplasm by double-membrane nuclear envelope.
Nuclear pores permit passage in and out of the nucleus.

19. Anatomy of Nucleus

20. Ribosomes
Composed of large and small subunits that serve in protein synthesis.
Subunits made in nucleolus.
Occur singly and in groups, and may become attached to endoplasmic reticulum.

21. Endomembrane System
Consists of nuclear envelope, membranes of endoplasmic reticulum, Golgi apparatus, and several types of vesicles.
Restrict enzymatic reactions to specific compartments within cell.

22. Endomembrane System Endoplasmic Reticulum
Rough - Studded with ribosomes.
Smooth - No ribosomes.

23. Endoplasmic Reticulum

24. Endomembrane System
Golgi Apparatus
Consists of flattened, curved saccules.
Modifies proteins and lipids and packages them in vesicles.

25. Golgi Apparatus

26. Endomembrane System Lysosomes
Membrane-bounded vesicles produced by the Golgi apparatus.
Engage in digestion of molecules and apoptosis (programmed cell death).

28. Peroxisomes
Peroxisomes are membrane-bounded vesicles that enclose enzymes.
Enzymes are cell-specific

29. Vacuoles Vacuoles are membranous sacs that are larger than vesicles.
Store substances
Plants cells typically have a central vacuole that functions in storage of nutrients and waste products.

30. Energy-Related Organelles
Chloroplasts use solar energy to synthesize carbohydrates.
Photosynthesis
Cellular Respiration
Adenosine triphosphate (ATP) is used for all energy-requiring processes in cells.

31. Energy-Related Organelles
Chloroplasts are green due to the green pigment chlorophyll.
Stroma
Granum

32. Chloroplast Structure

33. Energy-Related Organelles
Mitochondria are involved in cellular respiration.
Produce most of ATP utilized by the cell.
Cristae - Inner membrane that encloses matrix.
Matrix - Enzymes that break down nutrient molecules.

34. Mitochondrion Structure

35. Cytoskeleton
Cytoskeleton serves as internal skeleton that maintains cell shape and assists in movement of its parts.
Actin Filaments
Pseudopods
Intermediate Filaments
Microtubules

36. Centrioles, Cilia, and Flagella
Centrioles are short cylinders with a pattern of microtubule triplets that may give rise to basal bodies of cilia and flagella.

37. Cilia and Flagella
Cilia and flagella are hairlike projections with a pattern of microtubules that aid in cell movement.
In eukaryotes, cilia are much shorter than flagella.

39. Review Cell Theory Cell Size Prokaryotic Cells Eukaryotic Cells
Organelles
Nucleus
Endomembrane System
Cytoskeleton
Centrioles, Cilia, and Flagella