DNA Lab Guide

1

View DNA Structure

The DNA double helix is displayed in 3D. Click and drag to rotate. Scroll to zoom in/out.

2

Build Custom DNA

Click the A, T, G, C buttons to build your own DNA sequence. Watch it form in real-time!

3

Transcribe & Translate

Convert DNA to mRNA, then watch proteins being built amino acid by amino acid.

4

Simulate Mutations

Add random mutations and see how they affect the protein sequence!

DNA & RNA Chemical Structure Guide

DNA

Deoxyribonucleic Acid

  • Sugar: Deoxyribose (missing O at 2' position)
  • Bases: A, T, G, C
  • Structure: Double helix (anti-parallel)
  • Stability: More stable than RNA
  • Location: Nucleus (mainly)
RNA

Ribonucleic Acid

  • Sugar: Ribose (has OH at 2' position)
  • Bases: A, U, G, C (Uracil replaces Thymine)
  • Structure: Single stranded
  • Stability: Less stable, degrades faster
  • Location: Nucleus & Cytoplasm

Nucleotide Structure

Each nucleotide consists of three components:

Phosphate Group
PO₄³⁻
Pentose Sugar
Deoxyribose/Ribose
Nitrogenous Base
A, T, G, C or U

Bonding Patterns

A-T Pair: 2 hydrogen bonds

A ══ T

G-C Pair: 3 hydrogen bonds

G ═══ C

Molecular Composition Notes

1

Basic Molecular Composition

DNA and RNA are polymers made of nucleotide monomers. Each nucleotide contains:

  • Phosphate group - provides negative charge, links nucleotides
  • Pentose sugar - 5-carbon sugar (deoxyribose in DNA, ribose in RNA)
  • Nitrogenous base - carries genetic information
2

Base Types & Structures

Purines (2 rings)
  • Adenine (A)
  • Guanine (G)
Pyrimidines (1 ring)
  • Cytosine (C)
  • Thymine (T) - DNA only
  • Uracil (U) - RNA only
3

Key Molecular Differences

Feature DNA RNA
Sugar Deoxyribose Ribose
Bases A, T, G, C A, U, G, C
Strands Double Single
Helix B-form (right-handed) A-form (varies)
4

Chargaff's Rules

In any DNA sample:

  • %A = %T (Adenine equals Thymine)
  • %G = %C (Guanine equals Cytosine)
  • %Purines = %Pyrimidines
  • GC content affects DNA stability (higher GC = more stable)

DNA Lab

DNA Structure View

Base Pairing Rules

A T
G C

A pairs with T (2 bonds), G pairs with C (3 bonds)

Statistics

12
Base Pairs
42%
GC Content
0
Genes Found
0
Mutations
Current Sequence
ATG-CGA-TCG-ATC