D. Cytoplasm- not an organelle but a compartment in equal stature as the others1. 70% water, and 10-15% proteins and much smaller number of lipids and polysaccarides2. Make the proteins in the cytoplasmE. Organelles3. Endoplasmic reticulum (ER) –a) nucleus has 2 lipid bilayers, and the outer mono-layer is continuous with the membrane of the ER(1) at certain points the bilayers of the nuclear membrane is continuous as wellb) Rough ER- certain regions that contains ribosomes, studded with them(1) Structure(a) often 80s ribosomes, means they are actively translating RNA to protein(b) like a semi-flattened sac structure- 2 monolayers with phosphotydylcerine on cytoplasmic side and phosphotidylcholine is in the lumen, membrane bound organelle(c) 60s are attached to the ER and there are anchor proteins that will anchor them in place on the rough ER(2) Function:(a) Protein synthesis- all protein synthesis is initiated in the cytoplasm(i) Option 1 - There is a leader sequence (very hyperpolar) that once 20 amino acids are made, all of the translation will stop and the ribosome will move and bind the large subunit to the ER and the protein will be threaded into the lumen of the ER(a) Then we will restart the protein synthesis process and finish the protein(b) Any protein made in rough er were made there- protein based hormones are made in the ER but leave but other proteins usually stay there(c) Sodium potassium ATPase has a leader sequence, it is made in the ER and transported out. The leader sequence is the ticket to the inside of the ER, and many get rid of it after the proteins are made(ii) Option 2- if there is no leader sequence, 99% of the time function in the cytoplasm if there is no leader sequence(iii) Can make peripheral proteins in the ER, or after synthesis can make a full transmembrane protein, can also detach and become luminal proteins depending on the code(iv) proteins can move within the entire bilayer with ease.(v) *** be aware that the protein translation is all technically occurring in the cytoplasm(vi) Option 3: there are other proteins coded by the genome that have a mitochondrial leader sequence- when this is made, protein synthesis does not stop, we simply make the entire protein and it has a mitochondrial leader sequence that can be escorted to the membrane of the mitochondria(a) functions in the mitochondria, not the cytoplasm(b) Glycosylation- process is adding sugar(i) usually add oligosaccharides (short polysaccharides that contain carbon chains of 3-25)(ii) there is a transmembrane lipid called dolichol that will build the oligosaccharides from scratch(a) puts together monosaccharide in a chain on the cytoplasmic side. All occurs in the cytoplasm.(b) commonly see 3 sugars here: n-acetylglucosamine, glucose, mannose(c) once entire thing is made in cytoplasm, it is flipped to the lumen, it is physically pulled across the membrane- (dolicol is a unique lipid in this way)(d) we eat some micro RNA that can ruin this(iii) glycosylases cut the oligosaccharide that was attached to the dolicol in the lumen and reattaches it to the protein(a) N- linked glycosylation- glycosylase binds this oligosaccharide to a very specific amino acid called asparagine (usually abriviated asn)- binds it to the amino acid terminus of the R group(b) the specific sequence that codes for this is asn- (any amino acid)- then serine(ser) or threonine(thr), going towards the carboxyl end, it will attach to that asparagnine nitrogen on the R groupc) smooth ER shaped like a tube in cross section, no ribosomes(1) Structure- mainly lipids(2) Function:(a) Lipid synthesisd) ER extends through a significant portion of the celle) transitional ER- changes into something elseBY 330 1st Edition Lecture 16 Outline of Last Lecture C. Semipermeability of membraneOutline of Current Lecture D. CytoplasmE. OrganellesCurrent LectureD. Cytoplasm- not an organelle but a compartment in equal stature as the others1. 70% water, and 10-15% proteins and much smaller number of lipids and polysaccarides 2. Make the proteins in the cytoplasmE. Organelles 3. Endoplasmic reticulum (ER) – a) nucleus has 2 lipid bilayers, and the outer mono-layer is continuous with the membrane of the ER(1) at certain points the bilayers of the nuclear membrane is continuous as wellb) Rough ER- certain regions that contains ribosomes, studded with them(1) Structure (a) often 80s ribosomes, means they are actively translating RNA to protein(b) like a semi-flattened sac structure- 2 monolayers with phosphotydylcerine on cytoplasmic side and phosphotidylcholine is in the lumen, membrane bound organelle (c) 60s are attached to the ER and there are anchor proteins that will anchor them in place on the rough ERThese 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.(2) Function:(a) Protein synthesis- all protein synthesis is initiated in the cytoplasm (i) Option 1 - There is a leader sequence (very hyperpolar) that once 20 amino acids are made, all of thetranslation will stop and the ribosome will move and bind the large subunit to the ER and the protein will be threaded into the lumen of the ER (a) Then we will restart the protein synthesis process and finish the protein (b) Any protein made in rough er were made there- protein based hormones are made in the ER but leave but other proteins usually stay there(c) Sodium potassium ATPase has a leader sequence, it is made in the ER and transported out. The leader sequence is the ticket to the inside of the ER, and many get rid of it after the proteins are made (ii) Option 2- if there is no leader sequence, 99% of the time function in the cytoplasm if there is no leader sequence (iii) Can make peripheral proteins in the ER, or after synthesis can make a full transmembrane protein, can also detach and become luminal proteins depending on the code(iv) proteins can move within the entire bilayer with ease.(v) *** be aware that the protein translation is all technically occurring in the cytoplasm (vi) Option 3: there are other proteins coded by the genome that have a mitochondrial leader sequence- when this is made, protein synthesis does not stop, we simply make the entire protein and it has a mitochondrialleader sequence that can be escorted to the membrane of the mitochondria(a) functions in the mitochondria, not the cytoplasm(b) Glycosylation- process is adding sugar (i) usually add