DNA and RNA Structure and Function

Flashcards based on key concepts about DNA and RNA structure, function, replication, transcription, translation, and gene regulation.

What are the two types of nitrogenous bases found in nucleic acids?

Purines (Adenine and Guanine) and Pyrimidines (Cytosine, Thymine, Uracil).

What is the structure of DNA?

DNA has a double helix structure.

What are the base pairings in DNA?

Adenine pairs with Thymine (A-T) and Guanine pairs with Cytosine (G-C).

What is the direction of DNA strand synthesis during replication?

DNA is synthesized in the 5' to 3' direction.

What enzyme adds nucleotides during DNA replication?

DNA polymerase.

What is the role of RNA primase in DNA replication?

RNA primase synthesizes RNA primers to initiate DNA synthesis.

What are telomeres and their function?

Telomeres protect eukaryotic DNA and prevent chromosome shortening.

What are the three types of RNA?

Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA).

What is the process of converting DNA into mRNA called?

Transcription.

What is the significance of the codon in mRNA?

Codons are sequences of three nucleotides that correspond to specific amino acids.

What is the function of a ribosome during translation?

Ribosomes facilitate the binding of tRNA to mRNA and the formation of peptide bonds.

What do introns and exons represent in a gene?

Exons are coding regions that are expressed, while introns are non-coding regions that are removed during mRNA processing.

How do regulatory RNAs influence gene expression?

Regulatory RNAs can bind to DNA and inhibit transcription.

What is the difference between inducible and repressible operons?

Inducible operons are active when a substrate is present; repressible operons are active until a product inhibits their function.

What do transposable elements (TEs) do?

TEs can move genes within the genome and can be passed to other bacteria.

What is a frameshift mutation?

A frameshift mutation occurs due to insertions or deletions that alter the reading frame of the genetic code.

What is horizontal gene transfer?

Horizontal gene transfer is the transfer of genes between non-parent organisms, occurring through processes like transformation and transduction.

What do antibiotics like Rifamycin and Actinomycin D do in relation to transcription?

They block bacterial RNA polymerase and inhibit transcription.

What happens during DNA replication at the replication fork?

Unwinding of DNA occurs, creating single-stranded templates for new DNA synthesis.