Bio Question

[txchexmex]

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I was looking over some questions in Cliffs DAT prep and one of them mentions that the cells of eukaryotic organisms contain a variety of organelles that can perform specific functions. Membranes surrounding organelles are composed of.....ANS: double layer of lipids with proteins embedded.


I am pretty sure that not all organelles are double layered...lysosomes are single if I could remember correctly while mitochondria and the nucleus are double layered?

Is this just a tricky question? Im sure the real thing will be more definite...

 

[Orgolover]

Hey. I think they are referring to the fact that it is a lipid BI-layer (composed of two layers) that compose each membrane. We think of it as one layer, but really it's a sandwich that has 2 pieces of bread---or in this case lipid coverings with hydrophilic middle. . . And i think you're right about the lysosome as well. Let me know if you hear otherwise. Hope this helps. 😛

 

[Shinpe]

All plasma membranes have a lipid bilayer, some have two bilayers (like nucleus and mitochondria), but each membrane has 2 layers of phospholipids facing away from each other.

I think only liposomes, which are not really organelles, can have a signle phospholipid layer because they carry lipid inside. (I might be wrong)

 

[txchexmex]

Ok I see. Even though lysosomes are considered single layered, they still have a lipid bilayer. Wiki also says that liposomes have a bilayer. Thanks guys!

 

[Shinpe]

Ok I see. Even though lysosomes are considered single layered, they still have a lipid bilayer. Wiki also says that liposomes have a bilayer. Thanks guys!

Yea liposomes have a bilayer. Lipoproteins (chylomicrons) were the ones that are single-layered because they need to be able to carry lipid inside, so the second lipid layer would be destructive to that end. That would be your LDL and HDL stuff, bad and good cholestrol stuff. But then again, they're not organelles inside cells.

 

[r8 dds]

The only organelle's that don't have a "lipid bilayer" is the centrioles. I think every other organelle has a lipid bilayer i believe.

 

[Shinpe]

The only organelle's that don't have a "lipid bilayer" is the centrioles. I think every other organelle has a lipid bilayer i believe.

hmmm, not sure if centrioles are considered organelles. Are they?? never thought of it that way ....

 

[Shinpe]

This actually makes me wonder how Adipocytes store fat, it can't be in a bilayer right? 'cause that just wouldn't work I think. Would it?

 

[r8 dds]

hmmm, not sure if centrioles are considered organelles. Are they?? never thought of it that way ....

In Cliff's AP Bio, I think they label Centrioles as "organelles" or as part of the MTOC's (microtubule organization centers)

 

[Shinpe]

In Cliff's AP Bio, I think they label Centrioles as "organelles" or as part of the MTOC's (microtubule organization centers)

Yea I reversed my thought on that one later. I mean, if ribosomes are considered organelles, centrioles are def organelles lol. I doubt there would be a vague question like that on the test though.