Question

Question 28 15 pts A microbe living in the environment will catabolize macromolecules, bring the parts into the cell, and through anabolism, rebuild new proteins. Why can't microbes simply import whole proteins and not expend ATP to make them via anabolic reactions? Relate your answer to microbial structure. HTML Editore BIVA - A. IE3311 x - El V 12pt Paragraph

Answer 1

There are small proteins in the membrane of bacterial cells known as porins which are responsible for the transport of molecules inside the cells. Through these porins, only small size molecules can pass but not very large molecules like entire proteins. So cells have to take the molecules in monomeric forms and then inside the cells they rebuild the polymeric forms. If there would be any mechanism to take larger molecules then cells would be doing that because cells are very much efficient in case of energy expenditure.