Eukaryotic mRNA Structure, Processing, and Translation Mechanisms

Eukaryotic mRNAs have a 5' cap structure that is essential for translation initiation.

True

The poly(A) tail at the 3' end of eukaryotic mRNA enhances translation efficiency.

True

Eukaryotic ribosomes recognize the start codon through direct binding to internal ribosome entry sites (IRES) in most cases.

False

The 5' untranslated region (5' UTR) of eukaryotic mRNAs can contain regulatory elements that affect translation.

True

Eukaryotic mRNAs are typically monocistronic, encoding only one protein per transcript.

True

Eukaryotic genes contain introns that must be removed during mRNA processing before translation can occur.

True

Eukaryotic translation initiation requires the scanning mechanism where the ribosome moves from the 5' cap to find the start codon.

True

Alternative splicing allows a single eukaryotic gene to produce multiple protein isoforms.

True

MicroRNAs (miRNAs) typically enhance translation of their target mRNAs in eukaryotes.

False

The nuclear envelope in eukaryotes allows for temporal separation of transcription and translation.

True

Eukaryotic mRNA processing includes 5' capping, 3' polyadenylation, and splicing of introns.

True

Eukaryotic transcription requires RNA polymerase II for mRNA synthesis and involves multiple transcription factors.

True

Eukaryotic genes contain promoter elements such as TATA boxes and CAAT boxes that regulate transcription.

True

Post-transcriptional modifications of eukaryotic mRNA occur in the cytoplasm after export from the nucleus.

False

Eukaryotic translation initiation factors (eIFs) are required for proper ribosome assembly and start codon recognition.

True

What is the function of the 5' cap structure in eukaryotic mRNA?

B) It is essential for translation initiation and ribosome binding

The poly(A) tail at the 3' end of eukaryotic mRNA:

C) Enhances translation efficiency and mRNA stability

How do most eukaryotic ribosomes recognize the start codon?

B) By scanning from the 5' cap to find the start codon

The 5' untranslated region (5' UTR) of eukaryotic mRNAs:

C) Can contain regulatory elements that affect translation

Eukaryotic mRNAs are typically:

B) Monocistronic, encoding only one protein per transcript

What happens to introns during eukaryotic mRNA processing?

C) They are removed during splicing before translation can occur

The scanning mechanism in eukaryotic translation initiation involves:

B) Ribosome movement from the 5' cap along the mRNA to locate the start codon

Alternative splicing in eukaryotes allows:

B) A single gene to produce multiple protein isoforms

What is the typical effect of microRNAs (miRNAs) on their target mRNAs in eukaryotes?

C) They repress translation or cause mRNA degradation

The nuclear envelope in eukaryotes provides:

B) Temporal separation of transcription and translation

Eukaryotic mRNA processing includes which of the following steps?

C) 5' capping, 3' polyadenylation, and splicing of introns

Which enzyme is responsible for mRNA synthesis in eukaryotes?

B) RNA polymerase II

Eukaryotic gene promoters typically contain:

C) Promoter elements such as TATA boxes and CAAT boxes

Where do most post-transcriptional modifications of eukaryotic mRNA occur?

B) In the nucleus before export to the cytoplasm

Eukaryotic translation initiation factors (eIFs) are required for:

C) Proper ribosome assembly and start codon recognition

The _____________ structure at the 5' end of eukaryotic mRNA is composed of 7-methylguanosine and is essential for translation initiation.

cap

In eukaryotes, the _____________ mechanism involves ribosome movement from the 5' cap along the mRNA to locate the start codon.

scanning

The enzyme _____________ is responsible for transcribing mRNA genes in eukaryotes and requires multiple transcription factors for proper function.

RNA polymerase II

_____________ are non-coding sequences within eukaryotic genes that must be removed during mRNA processing before translation can occur.

Introns

The process of _____________ allows a single eukaryotic gene to produce multiple protein variants by including or excluding different exons.

alternative splicing

Eukaryotic mRNAs are typically _____________, meaning they encode only one protein per transcript, unlike prokaryotic mRNAs.

monocistronic

The _____________ tail at the 3' end of eukaryotic mRNA enhances both translation efficiency and mRNA stability.

poly(A)

_____________ are small regulatory RNAs that typically repress translation or cause degradation of their target mRNAs.

MicroRNAs (miRNAs)

The three main steps of eukaryotic mRNA processing are 5' _____________, intron _____________, and 3' _____________.

capping, splicing, polyadenylation

Eukaryotic translation initiation factors (_____________ ) are required for proper ribosome assembly and start codon recognition.

eIFs