Yeast cells are eukaryotes, and they require a functional secretory pathway to grow and to maintain cellular organization. But surprisingly, when SRP is removed from yeast cells by deleting the relevant genes, the cells are still alive (although they grow slowly). a) How can yeast survive without SRP? Propose two alternative hypotheses. b) How might electron microscopy of normal and SRP-deficient yeast cells help you to distinguish between these two hypotheses?

Yeast cells are eukaryotes, and they require a functional secretory pathway to grow and to maintain cellular organization. But surprisingly, when SRP is removed from yeast cells by deleting the relevant genes, the cells are still alive (although they grow slowly). a) How can yeast survive without SRP? Propose two alternative hypotheses. b) How might electron microscopy of normal and SRP-deficient yeast cells help you to distinguish between these two hypotheses?

Curren'S Math For Meds: Dosages & Sol

11th Edition

ISBN:9781305143531

Author:CURREN

Publisher:CURREN

Chapter16: Adult And Pediatric Dosages Based On Body Surface Area

Section: Chapter Questions

Problem 7.2P

See similar textbooks

Similar questions

Before JCVI-syn3.0 was produced, what steps were used to create a synthetic Mycoplasma cell? Put the events below into the correct order. Drag and drop the events into the proper sequence from left to right. ▸ View Available Hint(s) First Step Transformed cells are detected by the presence of lacz, which causes them to cleave Xgal and produce a blue color. Yeast is transformed using Mycoplasma mycoides fragments. The synthetic chromosome is transformed into Mycoplasma capricolum. The synthetic Mycoplasma mycoides chromosome is purified. DNA fragments assemble through homologous recombination in yeast. Reset Help Last Step
A solution of pure αβ-tubulin dimers is thought tonucleate microtubules by forming a linear protofilamentabout seven dimers in length. At that point, the probabili-ties that the next αβ-dimer will bind laterally or to the endof the protofilament are about equal. The critical eventfor microtubule formation is thought to be the first lateralassociation (Figure Q16–2). How does lateral associationpromote the subsequent rapid formation of a microtu-bule?
Cytokinesis in plant cells is different than cytokinesis in animal cells. a) Explain why it has to be different, andb) briefly describe the processes in the two different cell types.
Name the dark, linear, thread-like structures that you can see in some of the onion root tip cells. What Biomolecule of heredity do they contain?
A useful technique for studying microtubule motors is to attach them by their tails to a glass coverslip (which can be accomplished quite easily because the tails stick avidly to a clean glass surface) and then allow them to settle. The microtubules may then be viewed in a light microscope as they are propelled over the surface of the coverslip by the heads of the motor proteins. Because the motor proteins attach at random orientations to the coverslip, however, how can they generate coordinated movement of individual microtubules rather than engaging in a tug-of-war? In which direction will microtubules crawl on a ‘bed’ of kinesin molecules (i.e., will they move plus-end first, or minus-end first)?
35. If radioactive thymidine were introduced into the growth medium of actively dividing cells, it would be incorporated into the DNA molecule ... a) during the G1 phase when the cell does most of its growth. b) during S phase. c) as the cell passes the G1 Restriction Point. d) when centromeres split so the two chromosomes can be separated. e) at any point in the cell cycle.
It was clear from the early days of studying devel-opment that certain “morphogenetic” substances werepresent in the egg and segregated asymmetrically intocells of the developing embryo. One such investigationin ascidian (sea squirt) embryos examined endodermalalkaline phosphatase, which could be visualized by a his-tochemical stain. Treatment of embryos with cytochalasinB stopped cell division, but did not block expression ofalkaline phosphatase at the appropriate time. Treatmentwith actinomycin D, which blocks transcription, did notinterfere with expression of alkaline phosphatase. Treat-ment with puromycin, which blocks translation, elim-inated expression of alkaline phosphatase. What is thelikely nature of the morphogenetic substance that givesrise to alkaline phosphatase?
(d) If one bacteria cell divides every 30 minutes, calculate the number of cells after (a) Assuming the bacterial cell divides every 20 minutes under standard conditions, (c) How many hours will it take to produce 8192 cells under the same conditions. If a bacterial culture with initial cells number (No) increases by a factor of 2 in one generation and n is the time as given by the formula in equation 1. N = (2")No -----(1) calculate the number of cell division in 4 hours. (b) Calculate the number of cells produced after 4 lhours. hours.
What mechanistic features are shared by (a) the formation of multivesicular endosomes by budding into the interior of an endosome and (b) the outward budding of HIV virus at the cell surface? You wish to design a peptide inhibi- tor/competitor of HIV budding and decide to mimic a portion of the HIV Gag protein in a synthetic peptide. Which portion of the HIV Gag protein would be a logical choice? What normal cellular process might this inhibitor block?
If the number of cells in a bacterial culture rises by a factor of two in one generation, and n is the duration as determined by the formula in equation 1, N is the number of people in the group (2") No way ——- (1) (a) Calculate the number of cell divisions in 4 hours assuming the bacterial cell divides every 20 minutes under normal settings; (b) Calculate the number of cells generated after 4 hours assuming the bacterial cell divides every 20 minutes under standard conditions. (c) Under the same circumstances, how long will it take to make 8192 cells? (d) Calculate the hours if one bacterium cell divides every 30 minutes.
For each of the following situations, provide a plausible explanation for how it could lead to unrestricted cell division.(a) Colon cancer cells often contain mutations in the gene encoding the prostaglandin E2 receptor. PGE2 is a growth factor required for the division of cells in the gastrointestinal tract.(b) Kaposi sarcoma, a common tumor in people with untreated AIDS, is caused by a virus carrying a gene for a protein similar to the chemokine receptors CXCR1 and CXCR2. Chemokines are cell-specific growth factors.(c) Adenovirus, a tumor virus, carries a gene for the protein E1A, which binds to the retinoblastoma protein, pRb. (d) An important feature of many oncogenes and tumor suppressor genes is their celltype specificity. For example, mutations in the PGE2 receptor are not typically found in lung tumors. Explain this observation. (Note that PGE2 acts through a GPCR in the plasma membrane.)
According to the “Hawaiian Punch" principle, different compartments of the secretory and endocytic pathways are topologically equivalent to each other and to the extracellular space. a) Explain how vesicular transport generates this topological equivalence. b) During mitosis in mammalian cells, the nuclear envelope breaks down into vesicles. Are the topological properties of the cell altered by this event? Justify your answer.