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9700 AS Level Biology/Topic 6 Nucleic acids and protein synthesis/7 interactive simulations/drag to rotate the 3D models

Nucleic acids and protein synthesis, made interactive

Seven 3D simulations covering Topic 6.1 Structure of nucleic acids and replication of DNA and 6.2 Protein synthesis. Build nucleotides, unwind the helix, run a replication fork, transcribe and translate a gene, splice out introns and mutate a gene.

1. Nucleotides and ATP 3D · 6.1

A nucleotide is a phosphate group, a pentose sugar and a nitrogen-containing base. Compare DNA and RNA nucleotides, the two types of base, and ATP.

drag to rotate · wheel to zoom

Molecule

2. The DNA double helix 3D · 6.1

Two antiparallel polynucleotide strands are held together by hydrogen bonds between complementary bases. Click a base pair, or unwind the helix into a ladder.

click a base pair · drag to rotate · wheel to zoom

Structure

BASE PAIR
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HYDROGEN BONDS
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3. Semi-conservative replication 3D · 6.1

During the S phase the double helix unzips and each strand acts as a template. DNA polymerase can only add nucleotides in the 5′ to 3′ direction, so one new strand is made continuously and the other in fragments.

drag to rotate · wheel to zoom

Replication fork

LEADING STRAND
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LAGGING FRAGMENTS
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4. Transcription 3D · 6.2

RNA polymerase unwinds a gene and builds mRNA complementary to the template (transcribed) strand. Watch the mRNA grow and peel away.

drag to rotate · wheel to zoom

Gene

5. Translation 3D · 6.2

At a ribosome, tRNA molecules with complementary anticodons bring amino acids to each codon of the mRNA, from the start codon to a stop codon.

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Ribosome

CODON
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ANTICODON
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AMINO ACID
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POLYPEPTIDE
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6. Introns and exons 3D · 6.2

In eukaryotes, the primary transcript contains non-coding introns. These are removed and the exons are joined to make the mRNA.

drag to rotate · wheel to zoom

Primary transcript

7. Gene mutations 3D · 6.2

A gene mutation is a change in the sequence of base pairs. Make a substitution, a deletion or an insertion in the start of the β-globin gene and see how the polypeptide changes.

drag to rotate · wheel to zoom

Mutation

Built for Cambridge AS & A Level Biology 9700, Topic 6. Molecules are simplified, not to scale, and structural formulae are not shown.

About this lab: Nucleic acids and protein synthesis

Seven interactive 3D simulations for Cambridge AS Level Biology 9700 topic 6 Nucleic acids and protein synthesis: DNA and RNA nucleotides, purines, pyrimidines and ATP, the antiparallel double helix with hydrogen bonds between A-T and C-G pairs, semi-conservative replication with leading and lagging strands, DNA polymerase and ligase, transcription by RNA polymerase from the template strand, translation with codons, tRNA anticodons and start and stop codons, removal of introns, and substitution, deletion and insertion mutations in the beta-globin gene.

Seven 3D simulations covering Topic 6.1 Structure of nucleic acids and replication of DNA and 6.2 Protein synthesis. Build nucleotides, unwind the helix, run a replication fork, transcribe and translate a gene, splice out introns and mutate a gene.

Nucleic acids and protein synthesis is a free, browser-based simulation for Cambridge International AS & A Level Biology 9700 (topic 6 Nucleic acids and protein synthesis). The course is assessed in Paper 1 (Multiple choice), Paper 2 (AS structured), Paper 3 (Advanced practical), Paper 4 (A Level structured), Paper 5 (Planning, analysis, evaluation). Syllabus for examination in 2025-2027. There are 7 tabs, each a self-contained experiment with its own controls and live readings, and nothing to install: it runs on a laptop, tablet or classroom projector.

Syllabus coverage

Full syllabus map: AS Level Biology 9700 topic 6.

How to use this simulation

  1. 1. Nucleotides and ATP. A nucleotide is a phosphate group, a pentose sugar and a nitrogen-containing base.
  2. 2. The DNA double helix. Two antiparallel polynucleotide strands are held together by hydrogen bonds between complementary bases.
  3. 3. Semi-conservative replication. During the S phase the double helix unzips and each strand acts as a template.
  4. 4. Transcription. RNA polymerase unwinds a gene and builds mRNA complementary to the template (transcribed) strand.
  5. 5. Translation. At a ribosome, tRNA molecules with complementary anticodons bring amino acids to each codon of the mRNA, from the start...
  6. 6. Introns and exons. In eukaryotes, the primary transcript contains non-coding introns.
  7. 7. Gene mutations. A gene mutation is a change in the sequence of base pairs.
  8. The buttons at the end of the tab strip give the scene the whole window (Full screen, Hide controls) and, on a dark stage, a projector-friendly palette (Light scene). Many scenes also have drag handles: drag them to change the set-up directly.

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