The yeast gal4 gene encodes a transcriptional regulator that can bind dna upstream of genes required for the metabolism of the sugar galactose and turn them on. gal4 has a dna binding domain and an activation domain. the dna-binding domain allows it to bind to the appropriate sites in the promoters of the galactose metabolism genes. the activation domain attracts histone-modifying enzymes and also binds to a component of the rna polymerase ii enzyme complex, attracting it to the promoter so that the regulated genes can be turned on when gal4 is also bound to the dna. when gal4 is expressed normally, the genes can be maximally activated. you decide to try to produce more of the galactose metabolism genes by overexpressing the gal4 protein at levels fiftyfold greater than normal. you conduct experiments to show that you are overexpressing the gal4 protein and that it is properly localized in the nucleus of the yeast cells. to your surprise, you find that too much gal4 causes the galactose genes to be transcribed only at a low level. what is the most likely explanation for your findings?

answer:

maybe this site will :

hope this

lexi richison

explanation:

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!