Figure 3.1 Anatomy of the generalized animal cell nucleus.
Nuclear envelope
Chromatin
Nucleolus
Nuclear
pores
Nucleus
Cytoplasm
(a)
Plasma
membrane
Rough ER
(b)
© 2012 Pearson Education, Inc.
Nucleus
Figure 3.1a Anatomy of the generalized animal cell nucleus.
Nucleus
Cytoplasm
Plasma
membrane
(a)
© 2012 Pearson Education, Inc.
Figure 3.1b Anatomy of the generalized animal cell nucleus.
Nuclear envelope
Chromatin
Nucleolus
Nuclear
pores
Rough ER
(b)
© 2012 Pearson Education, Inc.
Nucleus
Figure 3.2 Structure of the plasma membrane.
Extracellular fluid
(watery environment)
Glycoprotein Glycolipid
Cholesterol
Sugar
group
Polar heads of
phospholipid
molecules
Bimolecular
lipid layer
containing
proteins
Nonpolar tails
of phospholipid
molecules
© 2012 Pearson Education, Inc.
Channel
Proteins Filaments of
cytoskeleton
Cytoplasm
(watery environment)
Figure 3.3 Cell junctions.
Microvilli
Tight
(impermeable)
junction
Desmosome
(anchoring
junction)
Plasma
membranes of
adjacent cells
Connexon
Gap
Underlying Extracellular
basement space between (communicating)
junction
membrane cells
© 2012 Pearson Education, Inc.
Figure 3.4 Structure of the generalized cell.
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
© 2012 Pearson Education, Inc.
Figure 3.5 Synthesis and export of a protein by the rough ER.
Ribosome
mRNA
Rough ER
2
1
3
1 As the protein is synthesized on the
ribosome, it migrates into the rough ER
cistern.
2 In the cistern, the protein folds into its
functional shape. Short sugar chains
may be attached to the protein (forming
a glycoprotein).
Protein
3 The protein is packaged in a tiny
Transport
vesicle buds off
4
membranous sac called a transport
vesicle.
4 The transport vesicle buds from the
rough ER and travels to the Golgi
apparatus for further processing.
Protein inside
transport vesicle
© 2012 Pearson Education, Inc.
Figure 3.6 Role of the Golgi apparatus in packaging the products of the rough ER.
Rough ER
Cisterna
Proteins in cisterna
Membrane
Lysosome fuses with
ingested substances
Transport
vesicle
Golgi vesicle containing
digestive enzymes
becomes a lysosome
Pathway 3
Pathway 2
Golgi
apparatus
Pathway 1
Golgi vesicle containing
proteins to be secreted
becomes a secretory
vesicle
© 2012 Pearson Education, Inc.
Secretory vesicles
Proteins
Secretion by
exocytosis
Golgi vesicle containing
membrane components
fuses with the plasma
membrane
Plasma membrane
Extracellular fluid
Figure 3.7 Cytoskeletal elements support the cell and help to generate movement.
(b) Intermediate filaments
(a) Microfilaments
(c) Microtubules
Tubulin subunits
Fibrous subunits
Actin subunit
7 nm
Microfilaments form the blue
network surrounding the pink
nucleus.
© 2012 Pearson Education, Inc.
10 nm
Intermediate filaments form
the purple batlike network.
25 nm
Microtubules appear as gold
networks surrounding the
cells’ pink nuclei.
Figure 3.7a Cytoskeletal elements support the cell and help to generate movement.
(a) Microfilaments
Actin subunit
7 nm
Microfilaments form the blue
network surrounding the pink
nucleus.
© 2012 Pearson Education, Inc.
Figure 3.7b Cytoskeletal elements support the cell and help to generate movement.
(b) Intermediate filaments
Fibrous subunits
10 nm
Intermediate filaments form
the purple batlike network.
© 2012 Pearson Education, Inc.
Figure 3.7c Cytoskeletal elements support the cell and help to generate movement.
(c) Microtubules
Tubulin subunits
25 nm
Microtubules appear as gold
networks surrounding the
cells’ pink nuclei.
© 2012 Pearson Education, Inc.
Figure 3.8 Cell diversity.
Fibroblasts
Rough ER and Golgi
apparatus
No organelles
Nucleus
Erythrocytes
(a) Cells that connect body parts
Nucleus
Intermediate
filaments
Epithelial
cells
(b) Cells that cover and line body organs
Skeletal
muscle cell
Nuclei
Contractile
filaments
Smooth
muscle cells
(c) Cells that move organs and body parts
Fat cell
Lipid droplet
Lysosomes
Macrophage
Pseudo
pods
Nucleus
(d) Cell that stores
nutrients
(e) Cell that fights
disease
Processes
Rough ER
Nerve cell
Nucleus
(f) Cell that gathers information and controls body
functions
Flagellum
Nucleus
Sperm
(g) Cell of reproduction
© 2012 Pearson Education, Inc.
Figure 3.8a Cell diversity.
Fibroblasts
Rough ER and Golgi
apparatus
No organelles
Nucleus
Erythrocytes
(a) Cells that connect body parts
© 2012 Pearson Education, Inc.
Figure 3.8b Cell diversity.
Epithelial
cells
Nucleus
Intermediate
filaments
(b) Cells that cover and line body organs
© 2012 Pearson Education, Inc.
Figure 3.8c Cell diversity.
Skeletal
muscle cell
Contractile
filaments
Nuclei
Smooth
muscle cells
(c) Cells that move organs and body parts
© 2012 Pearson Education, Inc.
Figure 3.8d Cell diversity.
Fat cell
Lipid droplet
Nucleus
(d) Cell that stores
nutrients
© 2012 Pearson Education, Inc.
Figure 3.8e Cell diversity.
Lysosomes
Macrophage
Pseudopods
(e) Cell that fights
disease
© 2012 Pearson Education, Inc.
Figure 3.8f Cell diversity.
Processes
Rough ER
Nerve cell
Nucleus
(f) Cell that gathers information and controls body
functions
© 2012 Pearson Education, Inc.
Figure 3.8g Cell diversity.
Flagellum
Nucleus
Sperm
(g) Cell of reproduction
© 2012 Pearson Education, Inc.
Focus on Careers 3 Forensic Scientist
© 2012 Pearson Education, Inc.
Figure 3.9 Diffusion.
© 2012 Pearson Education, Inc.
Figure 3.10 Diffusion through the plasma membrane.
Extracellular fluid
Lipidsoluble
solutes
Lipidinsoluble
solutes
Small lipidinsoluble
solutes
Water
molecules
Lipid
bilayer
Cytoplasm
(a) Simple diffusion
of fat-soluble
molecules
directly through
the phospholipid
bilayer
© 2012 Pearson Education, Inc.
(b) Carrier-mediated facilitated
diffusion via protein carrier
specific for one chemical;
binding of substrate causes
shape change in transport
protein
(c) Channel-mediated (d)
facilitated diffusion
through a channel
protein; mostly ions
selected on basis of
size and charge
Osmosis, diffusion
of water through a
specific channel
protein (aquaporin)
or through the lipid
bilayer
Figure 3.10a Diffusion through the plasma membrane.
Extracellular fluid
Lipidsoluble
solutes
Cytoplasm
(a) Simple diffusion
of fat-soluble
molecules
directly through
the phospholipid
bilayer
© 2012 Pearson Education, Inc.
Figure 3.10b Diffusion through the plasma membrane.
Lipidinsoluble
solutes
© 2012 Pearson Education, Inc.
(b) Carrier-mediated facilitated
diffusion via protein carrier
specific for one chemical;
binding of substrate causes
shape change in transport
protein
Figure 3.10c Diffusion through the plasma membrane.
Small lipidinsoluble
solutes
(c) Channel-mediated
facilitated diffusion
through a channel
protein; mostly ions
selected on basis
of size and charge
© 2012 Pearson Education, Inc.
Figure 3.10d Diffusion through the plasma membrane.
Water
molecules
Lipid
bilayer
© 2012 Pearson Education, Inc.
(d) Osmosis, diffusion
of water through a
specific channel
protein (aquaporin)
or through the lipid
bilayer
Figure 3.11 Operation of the sodium-potassium pump, a solute pump.
© 2012 Pearson Education, Inc.
Figure 3.12 Exocytosis.
Extracellular
fluid
Plasma
membrane
SNARE
(t-SNARE)
1 The membranebound vesicle
Vesicle
SNARE
migrates to the
(v-SNARE) plasma membrane.
Molecule
to be
secreted
Secretory
vesicle
Cytoplasm
Fusion pore formed
Fused
SNAREs
2 There,
v-SNAREs bind
with t-SNAREs, the
vesicle and plasma
membrane fuse,
and a pore opens
up.
3 Vesicle
contents are
released to the
cell exterior.
(a) The process of exocytosis
(b) Electronmicrograph of a secretory vesicle
in exocytosis (100,000×)
© 2012 Pearson Education, Inc.
Figure 3.12a Exocytosis.
Extracellular
fluid
Plasma
membrane
SNARE
(t-SNARE)
Vesicle
SNARE
(v-SNARE)
Molecule
to be
secreted
Secretory
vesicle
1 The membranebound vesicle
migrates to the
plasma membrane.
Cytoplasm
Fusion pore formed
Fused
SNAREs
2 There,
v-SNAREs bind
with t-SNAREs, the
vesicle and plasma
membrane fuse,
and a pore opens
up.
3 Vesicle
contents are
released to the
cell exterior.
(a) The process of exocytosis
© 2012 Pearson Education, Inc.
Figure 3.12b Exocytosis.
© 2012 Pearson Education, Inc.
Figure 3.13 Events and types of endocytosis.
Extracellular
fluid
Plasma
membrane
Lysosome
Cytosol
Vesicle
1 Vesicle
fusing with
lysosome
for digestion
Ingested
substance
Release of
contents to
cytosol
2 Transport to plasma
membrane and exocytosis
of vesicle contents
Detached vesicle
containing ingested
material
Pit
(a)
© 2012 Pearson Education, Inc.
Extracellular
fluid
Pseudopod
(b)
Membrane
receptor
3 Membranes and
receptors (if present)
recycled to plasma
membrane
(c)
Cytoplasm
Bacterium
or other
particle
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid
Plasma
membrane
Lysosome
Cytosol
Vesicle
1 Vesicle
fusing with
lysosome
for digestion
Ingested
substance
Release of
contents to
cytosol
2 Transport to plasma
membrane and exocytosis
of vesicle contents
Detached vesicle
containing ingested
material
Pit
(a)
© 2012 Pearson Education, Inc.
3 Membranes and
receptors (if present)
recycled to plasma
membrane
Figure 3.13b Events and types of endocytosis.
Extracellular
fluid
Pseudopod
(b)
© 2012 Pearson Education, Inc.
Cytoplasm
Bacterium
or other
particle
Figure 3.13c Events and types of endocytosis.
Membrane
receptor
(c)
© 2012 Pearson Education, Inc.
Figure 3.14 Replication of the DNA molecule during interphase.
C
T
G
A
G
C
T
A
Key:
C
G
= Adenine
C
G
T
A
= Thymine
= Cytosine
= Guanine
T
A
C
G
T
A
C
G
G
G
T
C
A
T
T
A
T
T
C
G
G
T
A
A
C
C
G
© 2012 Pearson Education, Inc.
A
C
G
T
Old
(template)
strand
T
A
A
T
A
G
C
A
Newly
synthesized
strand
C
G
A
New
Old (template)
strand strand
forming
DNA of one chromatid
Figure 3.15 Stages of mitosis.
Centrioles
Chromatin
Centrioles
Forming
mitotic
spindle
Plasma
membrane
Nuclear
envelope
Nucleolus
Interphase
Chromosome,
consisting of two
sister chromatids
Early prophase
Metaphase
plate
Spindle
microtubules
Centromere
Centromere
Fragments of
nuclear envelope
Spindle
pole
Late prophase
Nucleolus
forming
Cleavage
furrow
Spindle
Sister
chromatids
Metaphase
© 2012 Pearson Education, Inc.
Daughter
chromosomes
Anaphase
Nuclear
envelope
forming
Telophase and cytokinesis
Figure 3.15 Stages of mitosis (1 of 6).
Centrioles
Plasma
membrane
© 2012 Pearson Education, Inc.
Interphase
Chromatin
Nuclear
envelope
Nucleolus
Figure 3.15 Stages of mitosis (2 of 6).
Centrioles
Forming
mitotic
spindle
Chromosome,
consisting of two
sister chromatids
© 2012 Pearson Education, Inc.
Early prophase
Centromere
Figure 3.15 Stages of mitosis (3 of 6).
Spindle
microtubules
Centromere
Fragments of
nuclear envelope
Late prophase
© 2012 Pearson Education, Inc.
Spindle
pole
Figure 3.15 Stages of mitosis (4 of 6).
Spindle
Metaphase
© 2012 Pearson Education, Inc.
Metaphase
plate
Sister
chromatids
Figure 3.15 Stages of mitosis (5 of 6).
Daughter
chromosomes
Anaphase
© 2012 Pearson Education, Inc.
Figure 3.15 Stages of mitosis (6 of 6).
Nucleolus
forming
Cleavage
furrow
Nuclear
envelope
forming
Telophase and cytokinesis
© 2012 Pearson Education, Inc.
A Closer Look 3.1 IV Therapy and Cellular “Tonics”
© 2012 Pearson Education, Inc.
Figure 3.16 Protein synthesis.
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
1 mRNA specifying
one polypeptide is
made on DNA template.
2 mRNA leaves
nucleus and attaches to
ribosome, and
translation begins.
Amino
acids
mRNA
Nuclear pore
Correct amino
acid attached
to each species
of tRNA by an
enzyme
Nuclear membrane
4 As the ribosome
moves along the
mRNA, a new amino
acid is added to the
growing protein chain.
5 Released tRNA
reenters the cytoplasmic
pool, ready to be
recharged with a new
amino acid.
Growing
Met polypeptide
chain
Gly
Ser
Phe
Ala
Synthetase
enzyme
lle
3 Incoming tRNA
recognizes a
complementary mRNA
codon calling for its amino
acid by binding via its
anticodon to the codon.
tRNA “head”
bearing anticodon
Peptide bond
Large ribosomal subunit
C G G
G C CA U AG UC
Codon
Direction of ribosome
advance; ribosome
Portion of
Small ribosomal subunit moves the mRNA strand
along sequentially
mRNA already
as each codon is read.
translated
© 2012 Pearson Education, Inc.
Figure 3.17 Classification and functions of epithelia.
Apical surface
Squamous
Basal
surface
Simple
Cuboidal
Apical surface
Basal
surface
Columnar
Stratified
(a) Classification based on number of cell layers
(b) Classification based on cell shape
Number of layers
Cell shape
One layer: simple epithelial tissues
More than one layer: stratified epithelial tissues
Squamous
Diffusion and filtration
Secretion in serous membranes
Protection
Cuboidal
Secretion and absorption; ciliated types
propel mucus or reproductive cells
Protection; these tissue types are rare
in humans
Columnar
Secretion and absorption; ciliated types
propel mucus or reproductive cells
Transitional
(c) Function of epithelial tissue related to tissue type
© 2012 Pearson Education, Inc.
Protection; stretching to accomodate
distension of urinary structures
Figure 3.17a Classification and functions of epithelia.
Basal
surface
Apical surface
Simple
Apical surface
Basal
surface
Stratified
(a) Classification based on number of cell layers
© 2012 Pearson Education, Inc.
Figure 3.17b Classification and functions of epithelia.
© 2012 Pearson Education, Inc.
Figure 3.17c Classification and functions of epithelia.
© 2012 Pearson Education, Inc.
Figure 3.18a Types of epithelia and their common locations in the body.
Air sacs of
lungs
Nucleus of
squamous
epithelial cell
Basement
membrane
(a) Diagram: Simple squamous
© 2012 Pearson Education, Inc.
Nuclei of
squamous
epithelial
cells
Photomicrograph: Simple
squamous epithelium forming part
of the alveolar (air sac) walls (185×).
Figure 3.18b Types of epithelia and their common locations in the body.
Simple
cuboidal
epithelial
cells
Nucleus of
simple
cuboidal
epithelial
cell
Basement
membrane
Basement
membrane
Connective
tissue
(b) Diagram: Simple cuboidal
© 2012 Pearson Education, Inc.
Photomicrograph: Simple cuboidal
epithelium in kidney tubules (250×).
Figure 3.18c Types of epithelia and their common locations in the body.
Simple
columnar
epithelial
cell
Nucleus of simple
columnar epithelial cell
Goblet cell
Basement
membrane
Connective
tissue
Basement
membrane
(c) Diagram: Simple columnar
© 2012 Pearson Education, Inc.
Photomicrograph: Simple columnar
epithelium of the small intestine
(430×).
Figure 3.18d Types of epithelia and their common locations in the body.
Cilia
Pseudostratified
epithelial
layer
Pseudostratified
epithelial
layer
Basement
membrane
(d) Diagram: Pseudostratified (ciliated)
columnar
© 2012 Pearson Education, Inc.
Basement
membrane
Connective
tissue
Photomicrograph: Pseudostratified
ciliated columnar epithelium lining
the human trachea (430×).
Figure 3.18e Types of epithelia and their common locations in the body.
Nuclei
Stratified
squamous
epithelium
Stratified
squamous
epithelium
Basement
membrane
(e) Diagram: Stratified squamous
© 2012 Pearson Education, Inc.
Photomicrograph: Stratified
squamous epithelium lining of
the esophagus (140×).
Basement
membrane
Connective
tissue
Figure 3.18f Types of epithelia and their common locations in the body.
Basement
membrane
Transitional
epithelium
Basement
membrane
Transitional
epithelium
Connective
tissue
(f) Diagram: Transitional
© 2012 Pearson Education, Inc.
Photomicrograph: Transitional epithelium lining of
the bladder, relaxed state (215×); surface rounded
cells flatten and elongate when the bladder fills
with urine.
Figure 3.19a Connective tissues and their common body locations.
Bone cells in
lacunae
Central canal
Lacunae
Lamella
(a) Diagram: Bone
© 2012 Pearson Education, Inc.
Photomicrograph: Cross-sectional view
of ground bone (300×).
Figure 3.19b Connective tissues and their common body locations.
Chondrocyte
(Cartilage cell)
Chondrocyte
in lacuna
Lacunae
Matrix
(b) Diagram: Hyaline cartilage
© 2012 Pearson Education, Inc.
Photomicrograph: Hyaline cartilage
from the trachea (500×).
Figure 3.19c Connective tissues and their common body locations.
Chondrocytes
in lacunae
Chondrocites in
lacunae
Collagen fiber
Collagen
fibers
(c) Diagram: Fibrocartilage
© 2012 Pearson Education, Inc.
Photomicrograph: Fibrocartilage of an
intervertebral disc (110×).
Figure 3.19d Connective tissues and their common body locations.
Ligament
Tendon
Collagen
fibers
Collagen
fibers
Nuclei of
fibroblasts
Nuclei of
fibroblasts
(d) Diagram: Dense fibrous
© 2012 Pearson Education, Inc.
Photomicrograph: Dense fibrous connective tissue
from a tendon (500×).
Figure 3.19e Connective tissues and their common body locations.
Mucosa
epithelium
Lamina
propria
Elastic
fibers
Collagen
fibers
Fibroblast
nuclei
Fibers of
matrix
Nuclei of
fibroblasts
(e) Diagram: Areolar
© 2012 Pearson Education, Inc.
Photomicrograph: Areolar connective tissue, a
soft packaging tissue of the body (300×).
Figure 3.19f Connective tissues and their common body locations.
Nuclei of
fat cells
Vacuole
containing
fat droplet
Nuclei of
fat cells
Vacuole
containing
fat droplet
(f) Diagram: Adipose
© 2012 Pearson Education, Inc.
Photomicrograph: Adipose tissue from the
subcutaneous layer beneath the skin (430×).
Figure 3.19g Connective tissues and their common body locations.
Spleen
White blood cell
(lymphocyte)
Reticular
cell
Blood
cell
Reticular fibers
Reticular
fibers
(g) Diagram: Reticular
© 2012 Pearson Education, Inc.
Photomicrograph: Dark-staining network
of reticular connective tissue (430×).
Figure 3.19h Connective tissues and their common body locations.
Blood cells
in capillary
Neutrophil
(white blood
cell)
White
blood cell
Red blood
cells
Red
blood cells
Monocyte
(white blood
cell)
(h) Diagram: Blood
© 2012 Pearson Education, Inc.
Photomicrograph: Smear of human blood (1300×)
Figure 3.20a Types of muscle tissue and their common locations in the body.
Nuclei
Part of muscle
fiber
(a) Diagram: Skeletal muscle
© 2012 Pearson Education, Inc.
Photomicrograph: Skeletal muscle (approx. 300×).
Figure 3.20b Types of muscle tissue and their common locations in the body.
Intercalated
discs
Nucleus
(b) Diagram: Cardiac muscle
© 2012 Pearson Education, Inc.
Photomicrograph: Cardiac muscle (430×).
Figure 3.20c Types of muscle tissue and their common locations in the body.
Smooth
muscle cell
Nuclei
(c) Diagram: Smooth muscle
© 2012 Pearson Education, Inc.
Photomicrograph: Sheet of smooth muscle (approx. 300×).
Figure 3.21 Nervous tissue.
Brain
Nuclei of
supporting
cells
Spinal
cord
Cell body
of neuron
Nuclei of
supporting
cells
Cell body
of neuron
Neuron
processes
Neuron
processes
Diagram: Nervous tissue
© 2012 Pearson Education, Inc.
Photomicrograph: Neurons (150×)
Figure 3.22 Summary of the major functions and body locations of the four tissue types: epithelial, connective, muscle,
and nervous tissues.
Nervous tissue: Internal communication
• Brain, spinal cord, and nerves
Muscle tissue: Contracts to cause movement
• Muscles attached to bones (skeletal)
• Muscles of heart (cardiac)
• Muscles of walls of hollow organs (smooth)
Epithelial tissue: Forms boundaries between different
environments, protects, secretes, absorbs, filters
• Lining of GI tract organs and other hollow organs
• Skin surface (epidermis)
Connective tissue: Supports, protects, binds
other tissues together
• Bones
• Tendons
• Fat and other soft padding tissue
© 2012 Pearson Education, Inc.
A Closer Look 3.2 Cancer—The Intimate Enemy
Chromosomes
1
mutation
2
mutations
3
mutations
4
mutations
Malignant
cell
Normal
cell
(a) Accumulation of mutations in the development of a cancer cell.
Colon wall
1
2
Cellular
changes:
Increased
Growth of polyp
cell division
DNA
changes:
Oncogene
activated
3
Growth of malignant
tumor (carcinoma)
Tumor suppressor Second tumor suppresgene inactivated sor gene inactivated
(b) Stepwise development of a typical colon cancer.
© 2012 Pearson Education, Inc.
A Closer Look 3.2a Cancer—The Intimate Enemy
© 2012 Pearson Education, Inc.
A Closer Look 3.2b Cancer—The Intimate Enemy
Colon wall
1
2
Cellular
changes:
Growth of polyp
Increased
cell division
DNA
changes:
Oncogene
activated
3
Growth of malignant
tumor (carcinoma)
Tumor suppressor Second tumor suppresgene inactivated
sor gene inactivated
(b) Stepwise development of a typical colon cancer.
© 2012 Pearson Education, Inc.