1. Cells and Tissues
Carry out all chemical activities needed to sustain life
Cells are the building blocks of all living things
Tissues are groups of cells that are similar in structure and function

2. Anatomy of the Cell Cells are not all the same
All cells share general structures
Cells are organized into three main regions
Nucleus
Cytoplasm
Plasma membrane
Figure 3.1a

3. The Nucleus Control center of the cell Contains genetic material (DNA)
Three regions
Nuclear membrane
Nucleolus
Chromatin
Figure 3.1b

4. Nuclear Membrane Nuclear Membrane Barrier of nucleus
Consists of a double phospholipid membrane
Contain nuclear pores that allow for exchange of material with the rest of the cell
Nucleoli
Nucleus contains one or more nucleoli
Sites of ribosome production
Ribosomes then migrate to the cytoplasm through nuclear pores

5. Chromatin Composed of DNA and protein Scattered throughout the nucleus
Chromatin condenses to form chromosomes when the cell divides

6. Plasma Membrane Barrier for cell contents Double phospholipid layer
Hydrophilic heads
Hydrophobic tails
Also contains protein, cholesterol, and glycoproteins
Microvilli
Finger-like projections that increase surface area for absorption

7. Plasma Membrane Extracellular fluid (watery environment) Glycoprotein
Glycolipid
Cholesterol
Sugar
group
Polar heads of
phospholipid
molecules
Bimolecular
lipid layer containing proteins
Channel
Nonpolar tails of phospholipid
molecules
Proteins
Filaments of
cytoskeleton
Cytoplasm
(watery environment)
Figure 3.2

8. Microvilli Tight (impermeable) junction Desmosome (anchoring junction)
Plasma
membranes of
adjacent cells
Connexon
Underlying
basement
membrane
Extracellular
space between
cells
Gap
(communicating)
junction
Figure 3.3

9. Cytoplasm Material outside the nucleus and inside the plasma membrane
Cytosol
Fluid that suspends other elements
Organelles
Metabolic machinery of the cell
“Little organs”
Inclusions
Non-functioning units (stored nutrients, cell products, etc.)

10. Figure 3.4 Chromatin Nuclear envelope Nucleolus Nucleus Plasma
membrane
Smooth endoplasmic
reticulum
Cytosol
Lysosome
Mitochondrion
Rough
endoplasmic
reticulum
Centrioles
Ribosomes
Golgi apparatus
Secretion being released
from cell by exocytosis
Microtubule
Peroxisome
Intermediate
filaments
Figure 3.4

11. Cytoplasmic Organelles
Ribosomes
Made of protein and RNA
Sites of protein synthesis
Found at two locations
Free in the cytoplasm
Attached to rough endoplasmic reticulum

12. Cytoplasmic Organelles
Endoplasmic reticulum (ER)
Fluid-filled tubules for carrying substances
Two types of ER
Rough Endoplasmic Reticulum
Studded with ribosomes
Site where building materials of cellular membrane are formed
Smooth Endoplasmic Reticulum
Functions in cholesterol synthesis and breakdown, fat metabolism, and detoxification of drugs

13. Cytoplasmic Organelles
Golgi apparatus
Modifies and packages proteins
Produces different types of packages
Secretory vesicles
Cell membrane components
Lysosomes

14. destined for exocytosis Secretion by exocytosis Extracellular fluid
Protein-
containing
vesicles pinch
off rough ER
and migrate to
fuse with
membranes of
Golgi
apparatus. 1
Rough ER ER
membrane
Phagosome
Plasma
mem-
brane
Proteins in
cisterna
Pathway C:
Lysosome containing
acid hydrolase
enzymes
Proteins are
modified within
the Golgi
compartments. 2
Vesicle becomes
lysosome
Proteins are
then packaged
within different
vesicle types,
depending on
their ultimate
destination. 3
Secretory
vesicle
Golgi
apparatus
Pathway B:
Vesicle membrane
to be incorporated
into plasma
membrane
Pathway A:
Vesicle contents
destined for exocytosis
Secretion by
exocytosis
Extracellular fluid
Figure 3.20

15. Cytoplasmic Organelles
Lysosomes
Contain enzymes that digest nonusable materials within the cell
Packaged by Golgi apparatus
Peroxisomes
Membranous sacs of oxidase enzymes
Detoxify harmful substances
Break down free radicals (highly reactive chemicals)
Replicate by pinching in half

16. Cytoplasmic Organelles
Mitochondria
“Powerhouses” of the cell
Change shape continuously
Carry out reactions where oxygen is used to break down food
Provides ATP for cellular energy

17. Cytoplasmic Organelles
Cytoskeleton
Network of protein structures that extend throughout the cytoplasm
Provides the cell with an internal framework
Figure 3.7a

18. (b) Intermediate filaments
(a) Microfilaments
(b) Intermediate filaments
(c) Microtubules
Tubulin subunits
Fibrous subunits
Actin subunit
7 nm
10 nm
25 nm
Microfilaments form the blue
network surrounding the pink
nucleus.
Intermediate filaments form
the purple batlike network.
Microtubules appear as gold
networks surrounding the
cells’ pink nuclei.
Figure 3.7a-c

19. Cytoplasmic Organelles
Centrioles
Rod-shaped bodies
Direct formation of mitotic spindle during cell division

20. Cellular Projections Not found in all cells Used for movement
Cilia moves materials across the cell surface
Flagellum propels the cell

21. Cell Diversity
Figure 3.8a–b

22. Cell Diversity
Figure 3.8c

23. Cell Diversity
Figure 3.8d–e

24. Cell Diversity
Figure 3.8f–g