Chapter 3--Study Guide (6th edition)
1. Critically read Chapter 3 up to page 91 right
before section 3.3; do not need to read
section 3.3 (Membrane Transport) section
and beyond
2. Comprehend Terminology (those in bold in
the textbook)
3. Study-- Figure questions, Think About It
questions, and Before You Go On (sectionending) questions
4. Do end-of-chapter questions:
– Testing your recall– 2, 4, 8, 9, 11, 12, 13, 19
– True or false– 3, 5, 6, 7
1
I. 3.1 Concept of Cellular
Structure
2
§ Development of the Cell Theory
– Hooke: in 1665, observed cork (plant) and
coined the name the ______.
– Schwann: in 1800’s concluded: all animals are
made of ________
#1--All organisms are composed of cells
– Pasteur: work with bacteria circa 1859
• disproved idea of spontaneous generation
(living things arise from nonliving matter)
#2--“cells arise only from ____________”
was established by the end of the 19th
century.
3
Modern Cell Theory
1. All organisms composed of cells.
2. The simplest structural and functional unit of life
is ___________.
3. An organism’s structure/functions are due to the
activities of its cells.
4. Cells come from preexisting cells; all
life traces its ancestry to the same original
cells.
5. The cells of all species have fundamental
similarities.
4
§ Cell Shapes (Figure 3.1)
1. Squamous
2. Polygonal
3. Cuboidal
4. Columnar
5. Spheroid
6. Discoid
7. Stellate
8. Fusiform
9. Fibrous
5
§ Cell Size (1)
1. Human cell size
– most range from _____ µm in diameter
– egg cells (very large)100 µm diameter,
– muscle cell up to 30 cm long and nerve
cell over 1 meter long. Can you see
them with the naked eyes?
6
§ Cell Size (2)
2. How large a cell can be? Is there a
limit?
– as cell enlarges, volume increases
faster/slower (circle one) than
surface area; why?
– the need for increased nutrients and
waste removal exceeds ability of
membrane surface to exchange.
Why?
See Fig. 3.2
7
Cell Surface Area and Volume
Large cell:
Small cell:
8
§ Cell Size (3)
• As a cell doubles in diameter, its volume
increases __________, but its surface area
increases only fourfold.
• A cell that is too large may have too little
plasma membrane to serve the metabolic
needs of its increased volume of
cytoplasm.
9
§ General Cell Structures
1. Plasma (Cell) membrane
2. Cytoplasm = cytosol = intracellular fluid
(ICF); cytoplasm includes:
– Organelles and cytoskeleton
3. Extracellular fluid (ECF)
Fig. 3.5
10
ECF
A typical cell





11
§ Resolution
Resolution— the ability to reveal detail
• Naked eye— resolution 100 micrometer
• Light microscope— resolution 200 nm;
What can be seen?
– surface membrane, nucleus and
cytoplasm including ______________
• Electron microscopes— resolution 1 nm;
What can be seen?
– cell ultrastructures of the cytoplasm:
• Fig. 3.3 & 3.4
12
Resolution versus Magnification
2.0 mm
• Magnification– both were 750X
• Resolution– Light vs. T. Electron Microscope
13
Example– Ultrastructure of a WBC
14
II. 3.2 The Cell Surface
15
§ The Plasma Membrane
1. (Structure) Appears as a pair of dark
parallel lines around cell with a thickness of
@ 7.5 nm.
2. Membrane defines ________________
3. Functions of plasma membrane:
– Controls interactions with other cells
– Controls passage of materials in and out of cell
Fig. 3.6a
16
Two adjacent cells
17
§ Membrane Lipids (1)—fluid mosaic
theory (Fig. 3.6)
18
18
Lipids (98% of the cell mem.) (2)
1. Phospholipid bilayer (75%)—
– ________ heads on each side
– _________ tails in the center
2. Cholesterol (20%)—
– Location?
– Affects membrane fluidity; How?
3. Glycolipids (5%)—
– Structure-– Location? On extracellular face
– Functions – form glycocalyx etc.
19
§ Membrane Proteins (1)
• Mem proteins constitute
– about 2% of the molecules found in plasma
mem
– 50% of the mem weight since they are larger
1. Integral (transmembrane) proteins
– most are glycoproteins
– pass completely through membrane
– hydrophilic regions—
– hydrophobic regions– location?
– Drift about or anchored to the cytoskeleton
20
Fig. 3.7
; Transmembrane protein (A and B)
A
B
21
Membrane Proteins (2)
2. Peripheral proteins
– Location?
– Association with other proteins—
Fig. 3.6
22
Peripheral
protein
EXTRACELLULAR FLUID
Also Glycoprotein
B
A
C
Peripheral protein
Transmembrane
Proteins—A, B, C
Cytoskeleton
§ Membrane Protein (3)-- Functions
Chemical
messenger
Breakdown
products
(b) Enzyme
(a) Receptor
Ions
(d) Gated
ion channel
(c) Ion Channel
(e) Cell-identity
marker
(f) Cell-adhesion
molecule
(CAM)
§Second Messengers
1. A messenger (Epi.) binds
to a surface receptor
2. This activates ________
3. G protein binds to an
enzyme, adenylate
cyclase, which converts
ATP to cAMP
4. cAMP activates a kinase
in the cytosol
5. Kinases activates or
inactivates other enzymes
25
The muddiest points
of this chapter?
18-26