Please answer all. Thank you! 1) You are testing some new fluorescent stains to
ID: 84300 • Letter: P
Question
Please answer all. Thank you!
1) You are testing some new fluorescent stains to see if they could help tell you about how the endomembrane system and the secretory pathway worked. For each of the following stains, state where you think it would be mainly localized in the cell.
a. A stain that bound to G proteins
b. A stain that bound to RNA and DNA polymerases
c. A stain that bound to enzymes that perform primary glycosylation
d. A stain that bound to enzymes that perform secondary glycosylation
e. A stain that binds to hydrolytic enzymes that break down proteins and lipids
f. A stain that binds to clathrin
g. A stain that binds to transfer RNAs
h. A stain that binds to DNA
2) What do you think would happen to an integral membrane protein that normally is localized to the plasma membrane, and has a N-terminal signal sequence and a long hydrophobic portion near the C-terminus, under each of the following conditions?
a) The gene that codes for the protein is mutated so it no longer has a signal sequence.
b) The gene that codes for the protein is mutated so it no longer has the long hydrophobic portion.
3) Name the cytoskeletal system with which is most likely to have each of the following proerties.
a. The system whose polymerization would be most affected by a depletion of cellular ATP
b. The system whose polymerization would be most affected by a depletion of cellular GTP
c. The system that can withstand the most tension
d. The system most associated with generating membrane-associated movements
e. The system whose functional subunit is a protein monomer.
f. The system whose functional subunit is a protein dimer.
g. The system whose functional subunit is a protein tetramer.
h. The system that forms a radial array in interphase (in animal cells)
i. The system that forms two interdigitated radial arrays during mitosis (in animal cells)
j. The system connected to spot desmosomes
4) You accidentally washed off the labels off of 3 drugs you were using to treat cells. One of the drugs inhibited myosin, one of them inhibited kinesin, and one of them inhibited dynein. You picked one of the drugs at random and used it on some of his immune cells that normally secrete antibodies. When you analyzed the cells you saw that the cleavage furrow seemed to be working fine, the Golgi were forming fine, but the ER was not very spread out in the cells and the cells were unable to secrete any antibodies. Which drug you likely used?
Explanation / Answer
To introduce ourselves little bit into the topic is to explain what is this system and why it is important- This is to say that endomembrane system is the collection of membranes inside and surrounding a eukaryotic cell, functioning to transfer of membranous vesicles or by direct physical contact; includes the nuclear envelope, the plasma membrane, the ER system, the Golgi apparatus, lysosomes, and vocuoles too.
1) a) G proteins are intra membrane proteins, it has got its 7 chains or the transmembrane receptors, so the A strain would be located in the plasma membrane in the cell,
b) RNA and DNA polymerases are found in the nucleus of a cell, so if the strain is present there, it would be positioned in the nucleus of a cell,
c) Enzymes that perform primary glycosylation- this is the location in Rough ER under primary glycosylation.
2. a) If the signal sequence is missing the protein will be not forming the hydrophobic spanning region, so the sequence from N-terminus could be forward the message that it receives,
b) If it is missing the hydrophobic portion, still the signal sequence is not carrying the message into the cell inside, so moreover the function from the N-terminus would word but fail to carry the message inside of a cell.
3. a) The cytoskeletal system using most ATP molecule would be, if we look into the skeletal muscle myosins uses the ATP to work and function,
b) Mircotubules are dependent on cellular GTPs,
c) Actin filaments can withstand the most tension in a cytoskeletal system,
4. The affected immune cell is not working because of the specific protein kinesin. As we know that this protein belongs to a class of motor proteins found in eukaryotic cells. This protein works along with the micrtubule filaments and uses ATP source, thus it is useful making the antibodies, without this the cells is suffering.