Download Chapter 3c - I Teach Bio

PowerPoint® Lecture Slide Presentation
by Patty Bostwick-Taylor,
Florence-Darlington Technical College
Cells and
Tissues
3
PART C
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
 Gene—DNA segment that carries a blueprint for
building one protein
 Proteins have many functions
 Building materials for cells
 Act as enzymes (biological catalysts)
 RNA is essential for protein synthesis
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Role of RNA
 Transfer RNA (tRNA)
 Transfers appropriate amino acids to the
ribosome for building the protein
 Ribosomal RNA (rRNA)
 Helps form the ribosomes where proteins are
built
 Messenger RNA (mRNA)
 Carries the instructions for building a protein
from the nucleus to the ribosome
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Transcription and Translation
 Transcription
 Transfer of information from DNA’s base
sequence to the complimentary base
sequence of mRNA
 Three-base sequences on mRNA are called
codons
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Transcription and Translation
 Translation
 Base sequence of nucleic acid is translated to
an amino acid sequence
 Amino acids are the building blocks of
proteins
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
mRNA specifying
one polypeptide
is made on
DNA template
Amino acids
mRNA leaves
nucleus and
attaches to
ribosome, and
translation
begins
mRNA
Nuclear pore
Correct amino
acid attached
to each species
of tRNA by an
enzyme
Nuclear membrane
Synthetase
enzyme
Growing polypeptide chain
As the ribosome
moves along the
mRNA, a new amino
acid is added to
the growing protein
chain
Met
Gly
Ser
Phe
Released tRNA
reenters the
cytoplasmic
pool, ready to
be recharged
with a new
amino acid
Peptide bond
Ala
Incoming tRNA
recognizes a
complementary
mRNA codon calling
for its amino acid by
binding via its
anticodon to the
codon
tRNA “head” bearing
anticodon
Large ribosomal subunit
C G G
AU U U C G C C A U A G U C C
Portion of
mRNA already
Small ribosomal
translated
subunit
Codon Direction of ribosome
advance; ribosome moves
the mRNA strand along
sequentially as each codon
is read
Figure 3.16
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
DNA
Cytoplasm
(site of translation)
mRNA specifying
one polypeptide
is made on
DNA template
mRNA
Nuclear pore
Nuclear membrane
Figure 3.16, step 1
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
mRNA specifying
one polypeptide
is made on
DNA template
mRNA leaves
nucleus and
attaches to
ribosome, and
translation
begins
mRNA
Nuclear pore
Nuclear membrane
Large ribosomal subunit
U A G U CC
Codon
Small ribosomal
subunit
Figure 3.16, step 2
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
mRNA specifying
one polypeptide
is made on
DNA template
Amino acids
mRNA leaves
nucleus and
attaches to
ribosome, and
translation
begins
mRNA
Nuclear pore
Correct amino
acid attached
to each species
of tRNA by an
enzyme
Nuclear membrane
Synthetase
enzyme
Large ribosomal subunit
U A G U CC
Codon
Small ribosomal
subunit
Figure 3.16, step 3
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
mRNA specifying
one polypeptide
is made on
DNA template
Amino acids
mRNA leaves
nucleus and
attaches to
ribosome, and
translation
begins
mRNA
Nuclear pore
Correct amino
acid attached
to each species
of tRNA by an
enzyme
Nuclear membrane
Synthetase
enzyme
Incoming tRNA
recognizes a
complementary
mRNA codon calling
for its amino acid by
binding via its
anticodon to the
codon
tRNA “head” bearing
anticodon
Large ribosomal subunit
U A G U CC
Codon
Small ribosomal
subunit
Figure 3.16, step 4
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
mRNA specifying
one polypeptide
is made on
DNA template
Amino acids
mRNA leaves
nucleus and
attaches to
ribosome, and
translation
begins
mRNA
Nuclear pore
Correct amino
acid attached
to each species
of tRNA by an
enzyme
Nuclear membrane
Synthetase
enzyme
Growing polypeptide chain
As the ribosome
moves along the
mRNA, a new amino
acid is added to
the growing protein
chain
Met
Gly
Ser
Phe
Peptide bond
Ala
Incoming tRNA
recognizes a
complementary
mRNA codon calling
for its amino acid by
binding via its
anticodon to the
codon
tRNA “head” bearing
anticodon
Large ribosomal subunit
C G G
G C C A U A G U CC
Codon
Small ribosomal
subunit
Direction of ribosome
advance; ribosome moves
the mRNA strand along
sequentially as each codon
is read
Figure 3.16, step 5
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Nucleus
(site of transcription)
Cytoplasm
(site of translation)
DNA
mRNA specifying
one polypeptide
is made on
DNA template
Amino acids
mRNA leaves
nucleus and
attaches to
ribosome, and
translation
begins
mRNA
Nuclear pore
Correct amino
acid attached
to each species
of tRNA by an
enzyme
Nuclear membrane
Synthetase
enzyme
Growing polypeptide chain
As the ribosome
moves along the
mRNA, a new amino
acid is added to
the growing protein
chain
Met
Gly
Ser
Phe
Released tRNA
reenters the
cytoplasmic
pool, ready to
be recharged
with a new
amino acid
Peptide bond
Ala
Incoming tRNA
recognizes a
complementary
mRNA codon calling
for its amino acid by
binding via its
anticodon to the
codon
tRNA “head” bearing
anticodon
Large ribosomal subunit
C G G
AU U U C G C C A U A G U CC
Portion of
mRNA already
Small ribosomal
translated
subunit
Codon
Direction of ribosome
advance; ribosome moves
the mRNA strand along
sequentially as each codon
is read
Figure 3.16, step 6
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Body Tissues
 Tissues
 Groups of cells with similar structure and
function
 Four primary types
 Epithelial tissue (epithelium)
 Connective tissue
 Muscle tissue
 Nervous tissue
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Epithelial Tissues
 Locations
 Body coverings
 Body linings
 Glandular tissue
 Functions
 Protection
 Absorption
 Filtration
 Secretion
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Epithelium Characteristics
 Cells fit closely together and often form sheets
 The apical surface is the free surface of the tissue
 The lower surface of the epithelium rests on a
basement membrane
 Avascular (no blood supply)
 Regenerate easily if well nourished
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Epithelium Characteristics
Figure 3.17a
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Classification of Epithelia
 Number of cell layers
 Simple—one layer
 Stratified—more
than one layer
Figure 3.17a
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Classification of Epithelia
 Shape of cells
 Squamous
 flattened
 Cuboidal
 cube-shaped
 Columnar
 column-like
Figure 3.17b
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Simple Epithelia
 Simple squamous
 Single layer of flat cells
 Usually forms membranes
 Lines body cavities
 Lines lungs and capillaries
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Simple Epithelia
Figure 3.18a
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Simple Epithelia
 Simple cuboidal
 Single layer of cube-like cells
 Common in glands and their ducts
 Forms walls of kidney tubules
 Covers the ovaries
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Simple Epithelia
Figure 3.18b
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Simple Epithelia
 Simple columnar
 Single layer of tall cells
 Often includes mucus-producing goblet cells
 Lines digestive tract
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Simple Epithelia
Figure 3.18c
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Simple Epithelia
 Pseudostratified columnar
 Single layer, but some cells are shorter than
others
 Often looks like a double layer of cells
 Sometimes ciliated, such as in the respiratory
tract
 May function in absorption or secretion
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Simple Epithelia
Figure 3.18d
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Stratified Epithelia
 Stratified squamous
 Cells at the apical surface are flattened
 Found as a protective covering where friction
is common
 Locations
 Skin
 Mouth
 Esophagus
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Stratified Epithelia
Figure 3.18e
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Stratified Epithelia
 Stratified cuboidal—two layers of cuboidal cells
 Stratified columnar—surface cells are columnar,
cells underneath vary in size and shape
 Stratified cuboidal and columnar
 Rare in human body
 Found mainly in ducts of large glands
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Stratified Epithelia
 Transitional epithelium
 Shape of cells depends upon the amount of
stretching
 Lines organs of the urinary system
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Stratified Epithelia
Figure 3.18f
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Glandular Epithelium
 Gland
 One or more cells responsible for secreting a
particular product
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Glandular Epithelium
 Two major gland types
 Endocrine gland
 Ductless since secretions diffuse into
blood vessels
 All secretions are hormones
 Exocrine gland
 Secretions empty through ducts to the
epithelial surface
 Include sweat and oil glands
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings