* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Class XIX Tissues and organ systems I – Epithelial tissues To Grow
Lipid signaling wikipedia , lookup
Interactome wikipedia , lookup
Biochemical cascade wikipedia , lookup
Expression vector wikipedia , lookup
Gene regulatory network wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Point mutation wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Signal transduction wikipedia , lookup
Endogenous retrovirus wikipedia , lookup
Biochemistry wikipedia , lookup
Paracrine signalling wikipedia , lookup
Protein–protein interaction wikipedia , lookup
Protein purification wikipedia , lookup
Gene therapy of the human retina wikipedia , lookup
Cryobiology wikipedia , lookup
Polyclonal B cell response wikipedia , lookup
Western blot wikipedia , lookup
Two-hybrid screening wikipedia , lookup
Class XIX Tissues and organ systems I – Epithelial tissues To Grow and Differentiate: We need to convert materials from the environment into components of organism ...what do we need to make? Structural elements of living organisms are composed of: 1. Nucleic acids (DNA, RNA and their variants) 2. Proteins 3. Fats 4. Carbohydrates 1. Carbon 2. Hydrogen 3. Oxygen 4. Nitrogen (5. Other elements) (N,P,F,C) (N,P,F,C) (N,P,F,C) (N,P) 1 Option 1: Make your molecules Option 2: Get your molecules PLANTS (make their own protein, fat, carbohydrate and nucleic acids) ANIMALS (get most of their own protein, fat, carbohydrate and nucleic acids) Can not make: -Essential amino acids (Met, Val, His, Thr, Phe, Leu, Ile, Typ, Lys) - Essential fatty acids (linoleic acid) -Require large amounts of minerals (Calcium, Iron, etc.) Therefore, animals need to ingest (eat) another living organisms which make or contains these substances ..once you eat, you’ll have to digest ! Almost all “polymers” in nature, need to be separated into monomers, if they are to be used for growth by animals. Fig. 21.2b (Campbell 5th ed.) 2 Fig. 21.4 What “digests” organic molecules? Detergent ACID Enzymes Fig. 21.11a (Enzymes: Mouth-saliva; Pancreas) (Acid: Stomach-acid; Enzymes: Pancreas) (Enzymes: Pancreas) (Detergent: Liver-bile; Enzymes: Pancreas) Table 21.11 3 Animals can’t “make” all of their own molecules, and in addition: Herbivores: digest all that they ingest effectively Carnivores: digest some of what they ingest effectively Fig 21.13a We use the molecules we digest to make 3 tissue types: -Ephitelial tissues (Endoderm derived) -Connetive tissues and Muscle tissue (Mesoderm derived) -Neuronal tissues (Ectoderm derived) 4 1. Epithelial tissues Fig. 20.4 1. Epithelial tissues Lumen (or exterior) symmetrically packed cells 2a. Connective tissues “binds and supports tissues” Fig. 20.5 5 2a. Connective tissues Organized as a mass 2b. Muscle tissue Fig. 20.6 “functions in movement” 2b. Muscle tissue organized in parallel sheets or “fibers” 6 3. Neural tissue Formed by neurons with branching extensions; function in transmitting neural signals 1. Epithelial tissues L. 17-1 1. Epithelial tissues stomach intestine mouth bladder eye L. 19-8 7 1. Epithelial tissues Intestine epithelium K+ L. 11-29 1. Epithelial tissues Stomach epithelium (parietal cells) L. 11-30 How can we “see” a parietal cell? 8 Using antibodies specific for parietal cells we can “see” these cells utilizing immunohistochemistry How can we “make” antibodies that recognize parietal cells? To be able to study these cells or to be able to make antibodies to proteins that are specifically found on “parietal” cells, we have to use “pure” parietal cells. But since these are normal cells, if we collect cells from the stomach and try to grow them in the laboratory (in tissue culture plates) they will dye. We therefore transfer an “oncogene” into a normal parietal cell or grow a cell from a “parietal cell cancer”. The cell then becomes immortal and it grows to form a uniform cell population. It becomes a “parietal cell-line” We can make cell-lines from cells of almost any tissue We can inject this cell into mice, which will make antibodies to proteins of the parietal cells. 9 We can then test the antibody the mouse makes by Western analysis (-) (+) Labeled antibody (w. radioactivity or fluorescence) specific for a protein found in parietal-cells (-) We think that the protein the antibodies recognize is a pump protein. How can we prove this is the case? (+) By “screening” a cDNA library we can identify the gene encoding the “parietal-cell specific protein” our antibody recognizes mRNA cDNA 10 By “screening” a cDNA library we can identify the gene encoding the “parietal-cell specific protein” our antibody recognizes By “screening” a cDNA library we can identify the gene encoding the “parietal-cell specific protein” our antibody recognizes By “screening” a cDNA library we can identify the gene encoding the “parietal-cell specific protein” our antibody recognizes 11 Once the cell harboring the plasmid is identified the plasmid can be purified.. ..and sequence analyzed 5’-ATGTCGGCTACTGCCTAGCAGGCGC….. by comparing this sequence to all the known cDNA sequences at NCBI by BLAST we can identify which gene product this is.. ..or, if the sequence corresponds to a gene whose function is unknown, then we can make the protein of this gene and purify it. Lyse Centrifugate Purify protein by chromatography 12 perform X-ray crystallography We can observe the crystal structure of the protein and by comparing its shape to that of others we can predict the function of the protein We can observe the crystal structure of the protein and by comparing its shape to that of others we can predict the function of the protein We can observe the crystal structure of the protein and by comparing its shape to that of others we can predict the function of the protein 13 Required reading: Legends and explanations associated with figures covered in class 1. Stomach contains 0.1M HCl. How does the epithelium of the stomach protect itself from HCl? 2. We learned how glucose and Na++ are absorbed by the intestinal epithelial cell. How are aminoacids, nucleotides, fats and other ions absorbed? 3. What is “transcytosis”? 4. Other than parietal cells, the epithelium of the stomach contains at least 4 other epithelial cells. What are these and what are their functions? 5. Even though there is acid in the stomach it does not kill some bacteria that constitute the “flora” of our gut. The large intestine, on the other hand, is full of bacteria. What are these bacteria and what is their function? 6. When patients are given antibiotics, they might develop diarrhea because the drugs kill bacteria that are normally present in the large intestine. Why should this cause diarrhea? 14