PowerPoint® Lecture Slide Presentation
by Patty Bostwick-Taylor,
Florence-Darlington Technical College
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
PART C 3
Cells and
Tissues
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
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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
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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
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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
Figure 3.16
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
mRNA leaves nucleus and attaches to ribosome, and translation begins
Synthetase enzyme
Amino acids
Cytoplasm (site of translation )
Correct amino acid attached to each species of tRNA by an enzyme
Growing polypeptide chain
Nuclear pore
Nuclear membrane
mRNA
As the ribosome moves along the mRNA, a new amino acid is added to the growing protein chain
Released tRNA reenters the cytoplasmic pool, ready to be recharged with a new amino acid
Direction of ribosome advance; ribosome moves the mRNA strand along sequentially as each codon is read
Small ribosomal subunit
Portion of mRNA already translated
tRNA “head” bearing anticodon
Large ribosomal subunit
Peptide bond
Incoming tRNA recognizes a complementary mRNA codon calling for its amino acid by binding via its anticodon to the codon
Codon
Ala
Phe
Ser
Gly
Met
C G G
G U U U C U C C A A G C C A U
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Figure 3.16, step 1
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
Cytoplasm (site of translation )
Nuclear pore
Nuclear membrane
mRNA
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Figure 3.16, step 2
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
mRNA leaves nucleus and attaches to ribosome, and translation begins
Cytoplasm (site of translation )
Nuclear pore
Nuclear membrane
mRNA
Small ribosomal subunit
Large ribosomal subunit
Codon
U G C C A U
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Figure 3.16, step 3
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
mRNA leaves nucleus and attaches to ribosome, and translation begins
Synthetase enzyme
Amino acids
Cytoplasm (site of translation )
Correct amino acid attached to each species of tRNA by an enzyme
Nuclear pore
Nuclear membrane
mRNA
Small ribosomal subunit
Large ribosomal subunit
Codon
U G C C A U
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Figure 3.16, step 4
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
mRNA leaves nucleus and attaches to ribosome, and translation begins
Synthetase enzyme
Amino acids
Cytoplasm (site of translation )
Correct amino acid attached to each species of tRNA by an enzyme
Nuclear pore
Nuclear membrane
mRNA
Small ribosomal subunit
tRNA “head” bearing anticodon
Large ribosomal subunit
Incoming tRNA recognizes a complementary mRNA codon calling for its amino acid by binding via its anticodon to the codon
Codon
U G C C A U
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Figure 3.16, step 5
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
mRNA leaves nucleus and attaches to ribosome, and translation begins
Synthetase enzyme
Amino acids
Cytoplasm (site of translation )
Correct amino acid attached to each species of tRNA by an enzyme
Growing polypeptide chain
Nuclear pore
Nuclear membrane
mRNA
As the ribosome moves along the mRNA, a new amino acid is added to the growing protein chain
Direction of ribosome advance; ribosome moves the mRNA strand along sequentially as each codon is read
Small ribosomal subunit
tRNA “head” bearing anticodon
Large ribosomal subunit
Peptide bond
Incoming tRNA recognizes a complementary mRNA codon calling for its amino acid by binding via its anticodon to the codon
Codon
Ala
Phe
Ser
Gly
Met
C G G
G C U C A G C C A U
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Protein Synthesis
Figure 3.16, step 6
Nucleus (site of transcription)
DNA
mRNA specifying one polypeptide is made on DNA template
mRNA leaves nucleus and attaches to ribosome, and translation begins
Synthetase enzyme
Amino acids
Cytoplasm (site of translation )
Correct amino acid attached to each species of tRNA by an enzyme
Growing polypeptide chain
Nuclear pore
Nuclear membrane
mRNA
As the ribosome moves along the mRNA, a new amino acid is added to the growing protein chain
Released tRNA reenters the cytoplasmic pool, ready to be recharged with a new amino acid
Direction of ribosome advance; ribosome moves the mRNA strand along sequentially as each codon is read
Small ribosomal subunit
Portion of mRNA already translated
tRNA “head” bearing anticodon
Large ribosomal subunit
Peptide bond
Incoming tRNA recognizes a complementary mRNA codon calling for its amino acid by binding via its anticodon to the codon
Codon
Ala
Phe
Ser
Gly
Met
C G G
G U U U C U C C A A G C C A U
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
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Epithelial Tissues
Locations
Body coverings
Body linings
Glandular tissue
Functions
Protection
Absorption
Filtration
Secretion
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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
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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
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Classification of Epithelia
Shape of cells
Squamous
flattened
Cuboidal
cube-shaped
Columnar
column-like
Figure 3.17b
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Simple Epithelia
Simple squamous
Single layer of flat cells
Usually forms membranes
Lines body cavities
Lines lungs and capillaries
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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
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Simple Epithelia
Figure 3.18b
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Simple Epithelia
Simple columnar
Single layer of tall cells
Often includes mucus-producing goblet cells
Lines digestive tract
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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
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Simple Epithelia
Figure 3.18d
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Stratified Epithelia
Stratified squamous
Cells at the apical surface are flattened
Found as a protective covering where friction
is common
Locations
Skin
Mouth
Esophagus
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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
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Stratified Epithelia
Transitional epithelium
Shape of cells depends upon the amount of
stretching
Lines organs of the urinary system
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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