Question

______ often base pairs with itself to fold into complex 3D shapes in the cell

Answer 1

RNA often base pairs with itself, creating complex 3D structures. These structures, which include the hairpin motif, are crucial for RNA's functionality and evolutionary conservation.

Step-by-step explanation:

The molecule that often base pairs with itself to fold into complex 3D shapes in the cell is RNA. Even though RNA is single stranded, it exhibits extensive intramolecular base pairing between complementary sequences, which allows it to form a variety of intricate three-dimensional structures. These structures are critical for the function of RNA in the cell, as they influence its interactions with other molecules, including those involved in the catalysis of chemical reactions and in the synthesis of proteins.

The hairpin structure of RNA is a common motif where the molecule folds back on itself, allowing complementary nucleotides to form intramolecular hydrogen bonds. RNA's ability to fold based on internal hydrogen bonding contributes to its diverse tertiary structures, which are conserved throughout evolution due to their functional importance. In addition, this characteristic enables RNA to play roles as both informational and catalytic molecules, exemplified by ribosomal RNAs (rRNAs) which are essential components of the ribosome's catalytic core.