1. A TOUR OF THE CELL OVERVIEW
CHAPTER 7
A TOUR OF THE CELL
OVERVIEW

2. I. HOW WE STUDY CELLS
A. MICROSCOPES PROVIDE WINDOWS TO THE WORLD OF THE CELL

3. II. A PANORAMIC VIEW OF THE CELL
A. PROKARYOTIC AND EUKARYOTIC CELLS DIFFER IN SIZE AND COMPLEXITY
ALL CELLS ARE BOUNDED BY PLASMA MEMBRANE
PROKARYOTIC: CELLS WITHOUT NUCLEI OR OTHER MEMBRANE ENCLOSED ORGANELLES. Ex. BACTERIA AND ARCHAEBACTERIA
EUKARYOTIC: CELLS WITH MEMBRANE ENCLOSED NUCLEI AND OTHER SPECIALIZED ORGANELLES IN THEIR CYTOPLASM Ex. ALL OTHER ORGANISMS

4. 7.4 PROKARYOTIC CELL

5. B. INTERNAL MEMBRANES COMPARTMENTALIZE THE FUNCTIONS OF A EUKARYOTIC CELL
THE PLASMA MEMBRANE: FUNCTIONS AS A SELECTIVE BARRIER (FIG. 7.6)

6. THERE ARE TWO MAIN TYPES OF EUKARYOTIC CELLS (FIG. 7.7 ANIMAL)

7. 7.8 PLANT

8. III. THE NUCLEUS AND RIBOSOMES
THE NUCLEUS CONTAINS A EUKARYOTIC CELL’S GENETIC LIBRARY
DNA IS ORGANIZED WITH PROTEINS INTO CHROMOSOMES, WHICH EXIST AS CHROMATIN IN NONDIVIDING CELLS
MACROMOLECULES PASS BETWEEN NUCLEUS AND CYTOPLASM THROUGH PORES IN THE NUCLEAR ENVELOPE

9. 7.9 NUCLEUS & ENVELOPE

10. B. RIBOSOMES BUILD A CELL’S PROTEINS
FREE RIBOSOMES IN THE CYTOSOL, AND BOUND RIBOSOMES ON THE OUTSIDE OF THE ENDOPLASMIC RETICULUM, SYNTHESIZE PROTEINS (FIG. 7.10)

11. IV. THE ENDOMEMBRANE SYSTEM
DEFINITION: THE COLLECTION OF MEMBRANES INSIDE AND AROUND A EUKARYOTIC CELL, RELATED EITHER THROUGH DIRECT PHYSICAL CONTACT OR BY THE TRANSFER OF MEMBRANOUS VESICLES

12. CISTERNAE: MEMBRANE ENCLOSED COMPARTMENTS.
A. THE ENDOPLASMIC RETICULUM MANUFACTURES MEMBRANES AND PERFORMS MANY OTHER BIOSYNTHETIC FUNCTIONS
CONTINOUS WITH THE NUCLEAR ENVELOPE, THE ENDOPLASMIC RETICULUM (ER) IS A NETWORK OF CISTERNAE.
CISTERNAE: MEMBRANE ENCLOSED COMPARTMENTS.
TRANSPORT VESSICLE: DISTRIBUTES ER’S PRODUCTS
TYPES OF ENDOPLASMIC RETICULUM
SMOOTH ER: LACKS RIBOSOMES; SYNTHESIZES STEROIDS, METABOLIZES CARBS.
ROUGH ER: HAS BOUND RIBOSOMES; PRODUCES PROTEINS

13. 7.11 ENDOPLASMIC RETICULUM

14. B. THE GOLGI APPARATUS FINISHES, SORTS, AND SHIPS CELL PRODUCTS
STACKS OF SEPARATE CISTERNAE MAKE UP THE GOLGI
PARTS OF GOLGI APPARATUS
CIS FACE: RECEIVES SECRETORY PROTEINS FROM THE ER IN TRANSPORT VESSICLES
TRANS FACE: MODIFIES, SORTS AND RELEASES PROTEINS IN TRANSPORT VESSICLES

15. 7.12 GOLGI APPARATUS

16. C. LYSOSOMES ARE DIGESTIVE COMPARTMENTS
LYSOSOMES ARE MEMBRANOUS SACS OF HYDROLYTIC ENZYMES
FUNCTION: BREAKDOWN CELL MACROMOLECULES FOR RECYCLING (7.13)

17. D. VACUOLES HAVE DIVERSE FUNCTIONS IN CELL MAINTENANCE
A PLANT CELL’S CENTRAL VACUOLE FUNCTIONS IN STORAGE, WASTE DISPOSAL, CELL GROWTH, AND PROTECTION

18. V. OTHER MEMBRANOUS ORGANELLES
A. MITOCHONDRIA AND CHLOROPLASTS ARE THE MAIN ENERGY TRANSFORMERS OF CELLS
MITOCHONDRIA: SITE OF CELLULAR RESPIRATION IN EUKARYOTES
STRUCTURE: OUTER MEMBRANE AND INNER MEMBRANE FOLDED INTO CRISTAE

19. 7.17 MITOCHONDRIA

20. CHLOROPLASTS: A TYPE OF PLASTID, CONTAINS CHLOROPHYLL AND OTHER PIGMENTS, WHICH FUNCTION IN PHOTOSYNTHESIS
STRUCTURE: TWO MEMBRANES SURROUND THE FLUID STROMA, WHICH CONTAINS THYLAKOIKS, OFTEN STACKED IN GRANA
DEFINITIONS:
CRISTAE: AN INFOLDING OF THE INNER MEMBRANE OF A MITOCHONDRION, THAT HOUSES THE ENZYME CATALYZING THE SYNTHESIS OF ATP
PLASTIDS: ONE OF A FAMILY OF CLOSELY RELATED PLANT ORGANELLES, INCLUDIND CHLOROPLASTS, CHROMOPLASTS, AND AMYLOPLASTS
STROMA: THE FLUID OF THE CHLOROPLAST SURROUNDING THE THYLAKOID MEMBRANE
THYLAKOIDS: A FLATTENED MEMBRANE SAC INSIDE THE CHLOROPLAST
GRANA: A STACKED PORTION OF THE THYLAKOID MEMBRANE IN THE CHLOROPLAST

21. 7.18 CHLOROPLAST

22. C. PEROXISOMES CONSUME OXYGEN IN VARIOUS METABOLIC FUNCTIONS
PEROXISOMES: ORGANELLES THAT BREAK DOWN VARIOUS SUBSTANCES; PRODUCE H202 AS WASTE

23. VI. THE CYTOSKELETON
A. PROVIDES STRUCTURAL SUPPORT TO CELLS FOR CELL MOTILITY AND REGULATION
STRUCTURE: MADE OF MICROTUBULES, MICROFILAMENTS, AND INTERMEDIATE FILAMENTS

24. 7.20 CYTOSKELETON

25. MICROTUBULES: HOLLOW CYLINDERS; SHAPE THE CELL, GUIDE MOVEMENT OF ORGANELLES, AID CHROMOSOME SEPARATION IN DIVIDING CELLS

26. CILIA AND FLAGELLA: MOTILE APPENDAGES CONTAINING MICROTUBULES DOUBLETS

27. MICROFILAMENTS: THIN RODS BUILT FROM THE PROTEIN ACTIN; FUNCTION IN MUSCLE CONTRACTION
INTERMEDIATE FILAMENTS: SUPPORT CELL SHAPE AND ORGANELLES IN PLACE

28. VII. CELL SURFACES AND JUNCTIONS
A. PLANT CELLS ARE ENCASED BY CELL WALLS
PLANT CELL WALLS ARE COMPOSED OF CELLULOSE FIBERS EMBEDDED IN OTHER POLYSACCHARIDES AND PROTEIN

29. 7.28 PLANT CELL WALLS

30. B. INTERCELLULAR JUNCTIONS HELP INTEGRATE CELLS INTO HIGHER LEVELS OF STRUCTURE AND FUNCTION
IN PLANTS
PLASMODESMATA: CYTOPLASMIC CHANNELS THAT PASS THROUGH ADJOINING CELL WALLS
IN ANIMALS
TIGHT JUNCTIONS: INTERCELLULAR JUNCTION THAT PREVENTS LEAKAGE OF MATERIAL BETWEEN CELLS
DESMOSOMES: FUNCTIONS AS AN ANCHOR; ACT AS SPOT WELDS TO HOLD TOGETHER TISSUES THAT UNDERGO CONSIDERABLE STRESS EX. SKIN/ HEART TISSUE
GAP JUNCTIONS: ALLOWS THE PASSAGE OF MATERIAL OR CURRENT BETWEEN CELLS (IONS AND SMALL MOLECULES) ; PREVENTS CYTOPLASMS OF EACH CELL FROM MIXING

31. 7.30 INTERCELLULAR JUNCTIONS IN ANIMALS