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Biochemistry Review (pg. 196-199) LDL vs. HDL

Posted: Wed Jul 03, 2019 8:26 am
by 931287m
Hello,

So my understanding is that LDL transports cholesterol towards the tissues that need it, while HDL transports cholesterol away from the tissues, to the liver for processing & excretion (pg. 197-198).

The figure on page 199 shows HDL transporting cholesterol toward the tissues. The diagram also shows LDL being returned to the liver, however my understanding from the text was that IDL could be returned to the liver, while LDL transports to tissues.

I guess I just don't see direct relation between the text and the figure. Any clarification would be greatly appreciated!

Thank you!

Re: Biochemistry Review (pg. 196-199) LDL vs. HDL

Posted: Thu Jul 04, 2019 6:34 pm
by 931287m
Just following up on this - I think it may have been skipped over.

Thanks

Re: Biochemistry Review (pg. 196-199) LDL vs. HDL

Posted: Fri Jul 05, 2019 7:37 pm
by NS_Tutor_Mathias
The version on the diagram is more correct, but the simplified form in the summary is more MCAT-appropriate levels of understanding. Anything in the weeds, like how these pathways work on a molecular level and where which uptake really happens, is very likely passsage material.

Reuptake of LDL in the liver does actually happen and is significant, and the functions of HDL described in the diagram also appear to be true. This is definitely a section worth some review in how we present this information, although everything you've read is accurate. I'll make sure this gets some attention!