Unformatted text preview: inside the bacterial cells. The cells are not growing, perhaps because the medium lacks an essential nutrient. 20. Glucose does not cross a membrane rapidly, because it takes an input of energy to associate the hydrophilic glucose molecule (dissolve it) in the hydrophobic lipid phase. That energy is analogous to activation energy of a chemical reaction. The channel allows the glucose to cross without acquiring the energy (or as much energy). There is, however, no chemical reaction during the crossing. 21. Many enzymes need a particular pH and sometimes a specific cofactor (metal ion, small organic molecule). You may have purified it away from its cofactor. You may have irreversibly denatured the enzyme during purification. You may have associated it (possibly covalently) with an inhibitor....
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This note was uploaded on 06/18/2010 for the course BIS 103 taught by Professor Abel during the Spring '08 term at UC Davis.
- Spring '08