Gene Expression I

These flashcards encompass key concepts from the Gene Expression lecture, focusing on RNA types, polymerases, transcription processes, and mRNA processing.

What are the three types of RNA polymerases and their associated functions?

RNA pol I produces rRNA, RNA pol II produces mRNA, and RNA pol III produces tRNA and other RNAs.

What does the Central Dogma of Molecular Biology state?

Information flows from DNA to RNA to Protein.

What is the role of the TATA box in gene transcription?

The TATA box is located in the core promoter region and helps position RNA polymerase for transcription initiation.

What are the two kinds of epigenetic modifications mentioned?

Methylation and acetylation.

What processing steps are involved in the maturation of eukaryotic mRNA?

Capping, splicing, and polyadenylation.

What is the function of enhancers in gene regulation?

Enhancers bind to specific DNA sequences to facilitate transcription by recruiting transcription factors and RNA polymerase.

How does alternative splicing contribute to protein diversity?

Alternative splicing allows for different combinations of exons to be joined, resulting in multiple protein isoforms from a single gene.

What is the significance of the poly A tail in mRNA?

The poly A tail stabilizes the mRNA and is involved in the regulation of gene expression.

What is hnRNA and its role in gene expression?

hnRNA (heterogeneous nuclear RNA) is the initial form of RNA synthesized before it is processed into mature mRNA.

What are spliceosomes, and what role do they play in mRNA processing?

Spliceosomes are complexes that facilitate the removal of introns and the joining of exons during mRNA splicing.

Describe the functions of transcription factors.

Transcription factors bind to promoters and enhancers to regulate gene expression by facilitating or inhibiting the recruitment of RNA polymerase.

What is the role of RNA Polymerase II in eukaryotic transcription?

RNA Polymerase II synthesizes mRNA from the DNA template during transcription.

What happens during the initiation phase of transcription?

Transcription factors help RNA polymerase bind to the promoter, and the DNA strands are unwound to form an open complex.

How does the RNA polymerase advance during transcription?

RNA polymerase moves along the template strand, synthesizing RNA in a 5' to 3' direction.

What are introns and exons in the context of pre-mRNA?

Exons are coding sequences that remain in the mature mRNA, while introns are non-coding sequences removed during splicing.

What are the consequences of splice site mutations?

Splice site mutations can lead to abnormal splicing, potentially resulting in disease.

Describe the role of the 5' cap in mRNA.

The 5' cap protects the RNA from degradation and helps in the recognition of mRNA by ribosomes.