Hello, I have been a question like this. Autoradiography was used to study the production of proteins in liver cells by using a radioactive tracer over a time period of 20 minutes. The results are then given from which i have plotted a graph that shows the

Nucleus: very low amount of radioactive proteins after 5 minutes, which barely increase over the whole 20 minutes

R ER: After 5 minutes is high and then decreases over 20 minutes with the rate of decrease slowing down

Golgi Body: starts low then gets high, and continues to climb up to the 20 minutes

Mitochondria: after 5 minutes very low and barely increases, very similar to the nucleus.

I have to explain these problems and i have done a lot of research into them however i didn’t get the explanations i wanted. For the nucleus, although there is no protein synthesis going on in the nucleus, lots of proteins have to enter it so it can function, production of ribosomes is just 1 example. Why don’t the results increase more?

The R ER makes sense to me

The Golgi only modifies and packages the proteins, they are then released into three different types of vesicles. Why doesn’t the data rise and then fall over the 20 minutes? or is it that the time frame for proteins to pass through the golgi is longer than 20 minutes (i would expect it too rise then level off, equilibrium, and then decline)

The mitochondria, although synthesizes some proteins, it imports far more, so why does it also stay low like the nucleus? is it that it’s rate of protein uptake is very slow?

Just to let you know i don’t have a lot of biology experience but i’ve been searching for the explanations to these questions and i’ve only found data which agrees with this data

Sorry about the long post, hope it makes sense. Any help would be really appreciated

Thanks