Week 14 — Readings & Resources · Gene Expression

Course: Introduction to Biology — General Biology I (BIOL 101) · Silver Oak University (fictional sample) · Prof. Castellano
Objective covered: Objective 7 — Explain how the information in DNA is expressed: the central dogma, transcription, the genetic code, and translation.

How to use this page

Everything here is a link to an external resource — open it in your browser, the same way you'd open a YouTube link. Nothing needs to be downloaded.

This week's load is deliberately light: 2 short videos + 2 short readings, grouped by the ideas from the lecture, plus optional free references and the tool you'll use in the lab. Watch or read one item per group and you're ready for the quiz; do all of them and you'll be very comfortable. Total time is roughly 35–45 minutes if you do everything, far less if you pick one per group.

Order that matches the lecture: ① the central dogma overview → ② transcription (DNA → mRNA) → ③ the genetic code & translation (mRNA → protein) → ④ try it yourself (decode a gene).

A habit to start now: before you trust any biology claim — in these resources or anywhere — ask the questions from class: Is the arrow DNA → RNA → protein? Did the RNA use U (not T)? Are the codons read in frame from AUG?

① The Central Dogma & ② Transcription (DNA → mRNA)

Maps to Lecture Segments 2–3. A gene is copied into a portable mRNA message (transcription, in the nucleus), and RNA uses uracil (U) wherever DNA would use thymine (T).

Video — "Protein Synthesis (Updated)" (Amoeba Sisters)
🔗 https://www.youtube.com/watch?v=oefAI2x2CQM
Why it earns the click: a friendly ~8-minute walk through the whole relay we built on the board — why proteins matter, then transcription, then translation, then how to read an mRNA codon chart. It uses the same DNA → mRNA → protein arrow and the same start/stop logic. (This is the single best one-stop video for the week.)
⏱ ~8 min

Animation — "DNA Transcription (Basic Detail)" (HHMI BioInteractive)
🔗 https://www.biointeractive.org/classroom-resources/dna-transcription-basic-detail
Why it's assigned: a short, gorgeous 3-D animation of a molecule unzipping the DNA and copying one strand into RNA — exactly the transcription step, made concrete. Watch it once to see what "copying the template into mRNA" actually looks like.
⏱ ~3 min

③ The Genetic Code & Translation (mRNA → protein)

Maps to Lecture Segments 4–5. The mRNA is read three bases at a time (codons); AUG starts (and = Met), UAA/UAG/UGA stop; the ribosome reads codons and tRNA brings amino acids, in the cytoplasm.

Reading — "The Genetic Code" (OpenStax Biology 2e, §15.1)
🔗 https://openstax.org/books/biology-2e/pages/15-1-the-genetic-code
Why it's assigned: the cleanest plain-language version of the central dogma and the code itself — that three mRNA nucleotides make one codon, that AUG is the start codon (and methionine), and that three of the 64 codons (UAA, UAG, UGA) are stops. Free to read online, no account needed.
⏱ ~10 min

Animation — "Translation (Basic Detail)" (HHMI BioInteractive)
🔗 https://www.biointeractive.org/classroom-resources/translation-basic-detail
Why it earns the click: a short 3-D animation of the ribosome reading mRNA three nucleotides at a time while tRNA molecules deliver amino acids (it uses hemoglobin as the example) — the translation half of the relay, made visual. Exactly Segment 5.
⏱ ~3 min

④ Try It Yourself — Decode a Gene

Maps to Lecture Segment 8 and the Lab. The skill of the week is the process: transcribe a strand, group into codons from AUG, read each codon off the chart.

Interactive — "Transcribe and Translate a Gene" (Learn.Genetics, University of Utah)
🔗 https://learn.genetics.utah.edu/content/basics/txtl/
Why it's assigned: a free, click-through tool where you transcribe a DNA sequence into RNA (it reminds you that A in DNA pairs with U in RNA) and then translate it to a protein, one codon at a time. This is the same tool you'll use in Lab 14 — try it here first so the lab is quick.
⏱ ~7 min

Optional one-stop references (free online)

• Khan Academy — Gene expression and regulation (AP Biology). A free unit with short articles and videos on the central dogma, transcription, and translation. A good place to slow down on any one step.
  🔗 https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation
• OpenStax Biology 2e, §15.5 — "Ribosomes and Protein Synthesis." A bit more detail on the ribosome and tRNA if you want to go deeper than the video. Free to read online.
  🔗 https://openstax.org/books/biology-2e/pages/15-5-ribosomes-and-protein-synthesis

Pick-one quick path (≈18 min total)

In a hurry? Do exactly these two and you'll be ready for the quiz:
1. Watch "Protein Synthesis (Updated)" (groups ①–③ — it covers the whole relay).
2. Open "Transcribe and Translate a Gene" (group ④) and decode one short sequence yourself.

Heads-up (links rot): these point to outside sites that occasionally move or rename pages. If a link ever fails, tell Prof. Castellano and use the OpenStax or Khan Academy references above in the meantime.