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Which of the following statements is not correct regarding eukaryotic ribosome?

1) Consists of one large and one small ribonucleoprotein subunits
2) Assembly of subunit requires import of cytoplasmic proteins
3) Subunits are exported individually from nucleus
4) Small subunits are responsible for catalyzing peptide bonds during translation (tRNA brings on energy to create a new peptide bond)
5) Assembly of subunits occurs in nucleolus

User Dextrey
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Final answer:

The incorrect statement regarding eukaryotic ribosomes is that the small subunit catalyzes the formation of peptide bonds; this function is actually carried out by the large subunit during translation.

Step-by-step explanation:

The statement about eukaryotic ribosomes that is not correct Small subunits are responsible for catalyzing peptide bonds during translation (tRNA brings on energy to create a new peptide bond).

Eukaryotic ribosomes, which are 80S complexes, consist of a small 40S and a large 60S subunit. It is the large subunit that is responsible for catalyzing peptide bonds during translation, not the small subunit. The small subunit's main role is to bind the mRNA template. Indeed, ribosome assembly begins in the nucleolus, where the necessary rRNAs and proteins are synthesized and initial assembly occurs. Subsequently, these subunits are exported to the cytoplasm where they can further mature and eventually come together to form a functional ribosome specifically during the initiation phase of translation. Incorrect statement 4 implies that the small subunit has this catalytic role, which is not the case.

User Lazar Kukolj
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