A short RNA molecule was isolated that demonstrated a hyperchromic shift, indicating secondary structure. Its sequence was determined to be
5'-AGGCGCCGACUCUACU-3'
Propose a two-dimensional model for this molecule.

Verified step by step guidance

1. Identify the sequence of the RNA molecule: 5'-AGGCGCCGACUCUACU-3'. Since RNA is single-stranded, secondary structure forms by intramolecular base pairing, typically between complementary bases.
2. Recall the base pairing rules for RNA: Adenine (A) pairs with Uracil (U), and Guanine (G) pairs with Cytosine (C). Also consider possible wobble pairs like G-U.
3. Look for regions within the sequence that can form complementary base pairs by aligning the sequence against itself in reverse to find potential stem regions (double-stranded segments).
4. Identify loops or bulges where bases do not pair, which are common in RNA secondary structures. These are usually found in regions where complementary pairing is not possible.
5. Sketch the two-dimensional model by drawing the RNA strand and indicating paired bases as stems (lines connecting paired bases) and unpaired bases as loops or bulges, reflecting the predicted secondary structure.

Key Concepts

RNA Secondary Structure

RNA secondary structure refers to the local base pairing interactions within a single RNA strand, forming structures like hairpins, loops, and stems. These structures arise from hydrogen bonding between complementary bases (A-U and G-C) and are crucial for RNA function and stability.

Hyperchromic Shift

A hyperchromic shift is an increase in UV absorbance observed when nucleic acid secondary structures melt or unfold. It indicates the presence of base pairing and stacking interactions in the RNA, as unpaired bases absorb more UV light than paired ones.

Base Pairing Rules in RNA

RNA base pairing primarily involves Watson-Crick pairs: adenine (A) pairs with uracil (U), and guanine (G) pairs with cytosine (C). These specific interactions guide the folding of RNA into stable secondary structures and are essential for predicting RNA models.