Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
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 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 Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings