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What happens to proteins with no signal sequence that are made in the cytosol? Question 3 options: They are taken up by lysosomes. They are degraded by proteases. They are returned to their organelle of origin. They are secreted. They remain in the cytosol.

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Answer:

The correct answer is: They remain in the cytosol.

Step-by-step explanation:

Eukaryotic proteins are made through a process called Translation, which always starts at the cytosol (except for the proteins that are made in the mitochondria).

While Translation is taking place, the peptide that is being synthesized is checked for molecular tags that will lead to a re-routing to another destination: proteins that have an amino sequence called 'signal peptide' will be sent to the endoplasmic reticulum for its translation to continue - the proteins that go this route are meant to be part of the endomembrane system, after that they can be bounded to the ER, the Golgi apparatus or the lysosomes.

Unlike the proteins mentioned before, there are proteins that will have no signal peptide - this means that they are meant to finish Translation in the cytosol. Some of these proteins will acquire a signal tag that will lead them to the nucleus or the mitochondria, for example, but if they don't they will stay permanently in the cytosol to perform their tasks in that place.

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