RNA Structure and Function Quiz

RNA Structure and Composition

• RNA is a single-stranded nucleic acid molecule composed of nucleotides, each consisting of a sugar molecule, a nitrogenous base, and a phosphate group.
• The nitrogenous bases in RNA are adenine (A), guanine (G), cytosine (C), and uracil (U).
• The sugar molecule in RNA is ribose, which has an additional hydroxyl group (-OH) compared to deoxyribose, the sugar found in DNA.
• The nucleotides in RNA are linked by phosphodiester bonds, which connect the 3′ carbon of one nucleotide to the 5′ carbon of the next nucleotide.

RNA Functions

• RNA plays a key role in protein synthesis, gene regulation, and information transfer.
• In protein synthesis, RNA serves as an intermediate between DNA and proteins.
• DNA contains the genetic information that encodes the sequence of amino acids in a protein, but it cannot directly interact with ribosomes. RNA can interact with ribosomes and carry the genetic code from DNA to the ribosomes, where proteins are synthesized.

RNA Types

• There are three main types of RNA: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).
• mRNA carries the genetic information from DNA to the ribosomes, where it is translated into a sequence of amino acids to form a protein.
• tRNA plays a critical role in the translation process by carrying amino acids to the ribosome, where they are added to the growing protein chain.
• rRNA forms the structural and functional core of ribosomes, where it catalyzes the formation of peptide bonds between amino acids to assemble a protein.

Transcription

• Transcription takes place in the nucleus and is a biological process wherein a segment of the DNA is copied to mRNA.
• During transcription, a strand of mRNA is made that is complementary to a strand of DNA.
• The strand of DNA that is used to synthesize mRNA is known as the template strand or Active strand (3'-----5'). The other strand is called the non-template or inactive strand (5'-----3').

RNA Processing

• The transcribed RNA is known as the pre-mRNA and is processed further to convert it into mature RNA.
• RNA processing includes capping, polyadenylation, and splicing.
• Capping involves the addition of a methylated guanine cap to protect the mRNA.

Gene Regulation

• RNA also plays a crucial role in gene regulation.
• Various types of non-coding RNA molecules, such as microRNA (miRNA), small interfering RNA (siRNA), and long non-coding RNA (lncRNA), regulate gene expression by binding to mRNA and blocking translation, initiating degradation, or promoting transcription by interacting with DNA or other proteins in the gene regulatory network.