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

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 Figure 3.16

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 UG C CAU

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 UG C CAU

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 UG C CAU

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 CGG GCUCAG C CAU

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis 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

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Glandular Epithelium  Gland  One or more cells responsible for secreting a particular product

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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