Organelles - nucleus, endoplasmic reticulum, and golgi body

[jumbogala]

Homework Statement

Hi everyone. I'm a high school teacher. My background is physics and math, but right now I'm teaching a course that involves some basic (grade 10) biology. I don't know much about bio, so I need your help!

Right now, we're studying the organelles. I'm trying to put together some information about how the organelles work together to make proteins. Hopefully this will make the organelle functions easier for the students to remember.

Basically, I just need to know if what I've written below is true. Any corrections would be helpful!

Homework Equations

The Attempt at a Solution

- The nucleus directs all of the cell's activities. It contains the cell's genetic material, which is called DNA. The DNA is like an instruction manual that tells the cell how to build proteins.

- The DNA travels to the rough endoplasmic reticulum (ER), which is studded with ribosomes. The ribosomes use the instructions in the DNA to synthesize proteins.

- The smooth endoplasmic reticulum acts like a pathway that connects the rough ER to the golgi body. The finished proteins travel along this pathway.

- The proteins end up in the golgi body, which sorts them and then packages them into vesicles. Vesicles are like bubbles within the cell. The vesicles can break through the cell membrane, carrying the proteins outside the cell to wherever they are needed.

 

[ProfuselyQuarky]

That sounds pretty good, though #3 is not familiar to me (probably just my own forgetfulness). You could also add that vesicles eat up the cells' waste. That's important. I took 10th grade bio last year. It was one of the best classes so far. Good luck teaching!

 

[epenguin]

The DNA travels to the rough endoplasmic reticulum (ER), which is studded with ribosomes. The ribosomes use the instructions in the DNA to synthesize proteins.
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Just a correction, we cannot write a book or even a short summary article for you. There are plenty, or even Wikipedia if you can't call in on a bookshop, in fact I think you could find better than some of what you say in school textbooks.

I don't know what 10th grade is but you cannot at this or any level give an impression that ribosomes act on DNA directly, and not mention transcription and Messenger RNA which is what is exported from the nucleus, not DNA, and which the ribosomes use as instructions for making the aminoacid sequences of proteins. There are only two copies of the DNA molecule per eukaryote cell, the ribosomes are using not two but many thousands of copies of messenger RNA in the case of an abundant protein.

 

[ProfuselyQuarky]

I don't know what 10th grade is but you cannot at this or any level give an impression that ribosomes act on DNA directly, and not mention transcription and Messenger RNA which is what is exported from the nucleus, not DNA, and which the ribosomes use as instructions for making the aminoacid sequences of proteins. There are only two copies of the DNA molecule per eukaryote cell, the ribosomes are using not two but many thousands of copies of messenger RNA in the case of an abundant protein.

Ah, I guess the education systems in European countries are a lot different than in the States. 10th grade is equivalent to, I believe, Year 11 in the UK. Students in that grade are usually 15-16 years of age. Thanks for the clarification about ribosomes and DNA.

 

[Kuzon]

Where did you find that the smooth ER transports proteins to the golgi apparatus? I am 90% sure it doesn't do this. Proteins that leave the rough ER are actually packaged into vesicles which head to the Golgi apparatus to be modified sorted. The smooth ER is important for manufacturing lipids like testosterone and estrogen, the detoxification of poisons and the storage of Ca+ ions. I've never heard of it transporting proteins though.

You might also want to mention that some ribosomes just float around in the cell while they make proteins, rather than being on the rough ER. These are called free ribosomes, and bound ribosomes are on the rough ER.