Question

Consider the transport of galactose across a semi-permeable membrane from the extracellular space ([galactose] = 2 mM) to the cytosol ([galactose] = 10 mM) under biochemically standard conditions. (R = 0.08206 L atm/mol K = 8.314 J/mol × K) (15 pts.) If ATP hydrolysis liberates 30.5 kJ/mol at standard conditions, approximately how many grams of ATP (507.2 g/mol) would be required to transport 260 g of galactose from the extracellular space to the cytosol?

the molecular weight for galactose is 180.155 g/mol. this example uses the equation for transport of glucose.

Answer 1

The apparent ratio of intracellular ([S]i) and extracellular ([S]o):

= ([S]i)/ ([S]o)

= 10/2

= 5mM is the difference to transport of galactose from extracellular space to cytosol.

If 507.2 g/mol ATP liberates energy 30.5 kJ/mol

then for 260 g/mol -------------?

260*30.5 / 507.2 = 15.63 energy is required to transport of galactose from extracellular space to cytosol.

Note: The provided answer is as per my knowledge may be or may not be 100% correct, but definitely relevant to your question thank you so much.