D2.2 - Gene expression (HL) Flashcards
What direction does RNA polymerase synthesize RNA?
RNA polymerase synthesizes RNA in the 5’ to 3’ direction.
What is the purpose of the 3’ polyadenylation?
3’ polyadenylation adds a poly-A tail to mRNA, protecting it from degradation and enhancing translation efficiency.
What role do nucleosomes play in transcription regulation?
Nucleosomes can prevent RNA polymerase from accessing DNA, silencing genes.
What is mRNA splicing?
mRNA splicing is the process of removing introns and joining exons in the mRNA.
What is the role of DNA methylation in gene expression?
DNA methylation involves adding methyl groups to cytosine bases, typically resulting in gene silencing.
What are transcription factors?
Transcription factors are proteins that bind to specific DNA sequences to enhance or repress transcription.
How does RNA polymerase read the DNA template?
RNA polymerase reads the DNA template strand in the 3’ to 5’ direction.
What is genomic imprinting?
Genomic imprinting is the phenomenon where certain epigenetic tags are retained in gametes, leading to phenotypic differences.
How can environmental factors influence gene expression?
Environmental factors like diet, stress, and toxins can affect gene expression through mechanisms like epigenetics.
What is 5’ capping in mRNA processing?
5’ capping involves adding a modified guanine nucleotide to the 5’ end of mRNA to protect it from degradation and assist in translation.
What is the function of promoters in gene expression?
Promoters are DNA sequences that serve as binding sites for RNA polymerase and transcription factors.
What is the significance of alternative splicing?
Alternative splicing increases protein diversity by allowing different combinations of exons in the final mRNA.
What is the transcriptome?
The transcriptome is the full set of RNA transcripts produced by the genome at any given time.
What is the proteome?
The proteome is the entire set of proteins produced by a cell, tissue, or organism at a given time.
What is the impact of hormones on gene expression?
Hormones regulate gene expression by binding to receptors and affecting transcription within the nucleus.