A.1.2.11 Directionality

Front

What links nucleotides in a strand of DNA or RNA?

Back

The phosphate group of one nucleotide is linked to the pentose sugar of the next nucleotide.

Front

What is the 3' terminal in a DNA or RNA strand?

Back

The 3' terminal is where the pentose sugar of the nucleotide is unlinked, with C3 available for linkage to another nucleotide.

Front

What is the 5' terminal in a DNA or RNA strand?

Back

The 5' terminal is where the phosphate group of the nucleotide is unlinked, attached to C5 of the pentose sugar.

Front

How does the directionality of DNA and RNA affect biological processes?

Back

Directionality affects replication, transcription, and translation, as strands and nucleotides must face the correct direction to fit enzyme active sites.

Front

In which direction does DNA replication occur?

Back

DNA replication occurs in the 5' to 3' direction.

Front

In which direction does transcription occur?

Back

Transcription occurs in the 5' to 3' direction.

Front

In which direction does translation occur?

Back

Translation occurs in the 5' to 3' direction.

Front

What is the role of RNA in translation?

Back

RNA carries sequence information for making a polypeptide by linking amino acids together.

Front

How are the two strands of DNA used during replication?

Back

Both strands are used as templates; they are antiparallel, with one strand moving in the same direction as replication and the other in the opposite direction.

Front

Which DNA strand is used as a template for RNA transcription?

Back

Only one strand is used, the one that allows RNA assembly to move in the same direction as transcription.