Study "DNA VS RNA", a flashcard deck on FORKSAI.
Define what a gene is according to molecular biology principles.
A gene is a specific sequence of DNA that carries the instructions to encode for an RNA molecule. This RNA molecule may then be translated into a protein, serving as the fundamental unit of heredity passed from parents to offspring.
How do promoters contribute to the regulation of gene expression?
Promoters are crucial regulatory elements because they serve as the specific binding site for RNA polymerase. This binding is the initial step that signals where transcription should begin, thereby controlling whether and when a gene is expressed.
Distinguish between the roles of co-activators and co-repressors in gene regulation.
Co-activators are proteins that interact with enhancers to increase the rate of transcription, effectively boosting gene expression. In contrast, co-repressors decrease transcription by interacting with other regulatory proteins, thereby suppressing gene expression.
Explain the primary function of RNA polymerase during transcription.
RNA polymerase is the enzyme responsible for catalyzing the synthesis of an RNA strand. It does this by reading the DNA template strand and incorporating complementary RNA nucleotides, effectively transcribing the genetic information from DNA to RNA.
Why is the 5' UTR (Untranslated Region) important for the initiation of translation?
The 5' UTR is critical for translation initiation because it contains sequences that interact directly with the ribosome. This interaction helps to correctly position the ribosome on the mRNA, ensuring that translation begins at the appropriate start codon.
Describe the directionality of RNA synthesis and DNA template reading during transcription.
During transcription, RNA is synthesized in the 5' to 3' direction. Concurrently, RNA polymerase reads the DNA template strand in the opposite, antiparallel direction, specifically from 3' to 5'.
How does an enhancer sequence influence gene expression, and where can it be located?
An enhancer sequence increases the rate of transcription for a gene. It can be located in various positions relative to the gene, including upstream, downstream, or even within the introns of the gene itself or other genes.
What is the role of transcription factors in the process of gene expression?
Transcription factors are proteins that bind to specific DNA sequences, playing a pivotal role in regulating gene expression. They can either activate transcription by recruiting RNA polymerase or repress it by blocking its access or activity.
Explain the function of mRNA in the process of translation.
mRNA (messenger RNA) carries the genetic code from DNA in the nucleus to the ribosomes in the cytoplasm. It contains the sequence of codons that dictates the specific order of amino acids to be incorporated into a polypeptide chain during protein synthesis.
What is the specific role of tRNA in decoding the genetic message during translation?
tRNA (transfer RNA) molecules are responsible for delivering the correct amino acids to the ribosome during translation. Each tRNA has an anticodon that base-pairs with a specific codon on the mRNA, ensuring the accurate assembly of the polypeptide chain.