You are studying nuclear protein import in human cells. To test the requirements for the Ran protein, you have set up an in vitro nuclear import assay. In this assay, human tissue culture cells are treated with digitonin, which permeabilizes the plasma membrane but leaves the nuclear envelope intact. Since permeabilization results in the release of all soluble cytoplasmic contents, you need to supplement the assay with cytosolic extracts that you have prepared from other cells. In this case, you are using extracts from cells that do not express the Ran protein so that you can supply recombinant Ran complexed with various nucleotides. To measure nuclear import, you are using a fluorescently-labeled protein that contains a classic NLS that you can monitor by fluorescent microscopy. Thus, you add cytosolic extract + Ran + fluorescent nuclear protein to the permeabilized cells and examine the nuclei for import of the nuclear protein. What do you expect to observe under the following conditions? Briefly explain your choices. a. What do you predict happens when you add Ran-GTP to the assay?
b. What do you predict happens when you add Ran-GDP to the assay?
c. What do you predict happens when you add Ran-GTP and Sinocol, a small 300 Da RanGAP inhibitor?

transcription is a process in which information is rewritten. it is something our cells must do, in a more specialized and narrowly defined way. in biology, transcription is the process of copying out the dna sequence of a gene in the similar alphabet of rna. it needs to happen in the nucleus because that's where the dna is. dna is always inside the nucleus unless the cell is dividing.

transcription is the first step in gene expression, which involves copying a gene's dna sequence to make an rna molecule. transcription is performed by rna polymerases. it has three stages: initiation, elongation, and termination. rna molecules must be processed after transcription in eukaryotes.

explanation:

long version:

the protein synthesis consists two processes which are, transcription and translation. transcription takes place in the nucleus. it uses dna as a template to make an rna molecule. rna then leaves the nucleus and goes to a ribosome in the cytoplasm, where translation occurs. transcription is the first part of the central dogma of molecular biology: dna → rna. it is the transfer of genetic instructions in dna to messenger rna (mrna). during transcription, a strand of mrna is made that is complementary to a strand of dna.  

these three stages are:

  initiation: in which   is the beginning of transcription.occuring when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

    elongation: in which is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

    termination: in which is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.