BMS 300 1st edition Lecture 11 Outline of Last Lecture I. Protein translation -on ribosomes in the cytoplasm -required RNA1. mRNA: codons for the amino acid sequence 2. tRNA: carries specific amino acid 3. rRNA: forms ribosomes which is a catalyst of peptide bond formation-concept of a codon1. set of three bases to encode on amino acid2. start codon AUG 3. open reading 4. stop codon II. Cytoplasmic proteins -deposited into cytoplasm -synthesized on free ribosomes III. Transmembrane, secreted, & liposomal proteins -roughIV. Targeting the ribosome, mRNA-complex to ER -signal peptideThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. NH2 end of protein 2. series of hydrophobic amino acids 3. role of signal recognition particle -SRP receptor, ribosome reception, protein translator in ER -transmembrane proteinOutline of Current Lecture V. Protein targeting to the endoplasmic reticulum -protein translocator 1. secreted lyosomal proteins2. transmembrane protein-glycosylating in the ER -------------------------------------------------------------------------------------------------------------------------------VI. Cells functioning in concert -tissues1. group of similar cells performing similar functionsVII. Types -epithelia -connective-muscle -nervous VIII. Epithelia -form borders/interfacesIX. Characteristics of Epithelia -continuous layer of cells -attached to basal lamina -oriented cells -able to replicate -cell functions X. Epithelia junctions Current Lecture-starting from last lecture we had the drawing of the endoplasmic reticulum and how it created a signal peptide -the signal peptide was hydrophobic, because it was composed primarily of uncharged R-groups on amino acids -the amino acids will be primarily hydrophobic-the amino acids will bind to the signal recognition particle -we brought the machine from in the cytoplasm, delivered it to the ER and it’s now latched on by the two receptors -energy goes into this and then breaks the bonds -across the membrane is a protein translocator aka the “trans locon”-it’s a pathway between the cytoplasm and the endoplasmic reticulum -the trans locon has segments of amino acids that are hydrophobic-while one section remains attached the other one gets pushed down into the ER makinga protein that is alone in the ER -the amino acids then attach to the protein in a process called glycosylation -these proteins can be “destined to be secreted to the outside world” or “lysosomal”-they will go to the plasma membrane and it will be determined where they are going -when we run across a protein with hydrophobic amino acids they will then bond to the other hydrophobic amino acids which will cause it to stay-all of this is how we make transmembrane proteins **we can now think about the rules of how to create a protein **functions that can apply in any different cellTissues-groups of similar cells preforming a similar function -4 types 1. epithelia: form boundaries/interfaces 2. connective: ties things together 3. muscle: allows us to move 4. nervous-primarily focusing on epithelia -when you see the term epithelia think of a continuous layer of cells that form a boundary Epithelia-composed of layers of continuous cells -show a series of boxes as a single layer of cells -the boxes as 3D shapes -sit on an underlying layer of protein called the basal lamina -the basal lamina is a layer of extra cellular proteins -epithelia cells are oriented with respect to the basal lamina -the layer that is attached to the basal lamina is the baslar surface -the layer that isn’t attaches is the apical surface which is facing the lumen -epithial cells form a lining of tubes that extend to the outside of the body-blood vessels are lined with a cellular layer called an endothelium -they also maintain the ability to divide and replicate Carcinoma: cancer/tumor that originated as an epithelial cell -the issue we have found with cancer is that it won’t attach to the basal lamina and it replicates itself without following any of the “rules” -there are anchoring junctions that attach to the epitical cells to the basal lamina called hemidesmonsomes -there are other anchoring junctions that attach cells to their neighbors called
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