Course: Introduction to Biology — General Biology I (BIOL 101) · Silver Oak University (fictional sample) · Prof. Castellano
Module: Week 3 of 16 · Fall 2026 · in-person, two 75-minute lectures + one weekly lab
Objective covered: Objective 2 — Apply the chemistry of life to the four classes of biological macromolecules, explaining how structure determines function.

This file holds two pieces: (A) the Module 3 Overview page ("Start Here") and (B) the Welcome Announcement that drips out when the module opens. Dates below assume a Tuesday/Thursday lecture pattern with Week 3 meeting Tue Sep 15 and Thu Sep 17, a lab that same week, and end-of-week work due Sunday Sep 20, 11:59 p.m. Adjust the day-of-week and times to match your section.

(A) Module 3 Overview — Start Here

Welcome to Week 3: Biological Macromolecules

This is your home base for the week. Read it first, then work the checklist below from top to bottom. Everything you need is linked inside the module.

Last week we built life from atoms, bonds, and water. This week we go up one level: the four families of large molecules that life is actually made of — carbohydrates, lipids, proteins, and nucleic acids. You eat all four every day, you're built from all four right now, and almost everything a cell does, one of these molecules does it. The headline idea for the whole week is short and powerful: structure determines function. The shape and the building-block sequence of a molecule decide what it can do — which is why a single wrong amino acid can cause sickle-cell disease, and why the same sugar, glucose, can be both your quick fuel and a tree's rigid wall.

The week's big question

"Life is built from just four kinds of large molecules — so how does the structure of each one decide what it can do?"

By Friday you'll be able to name the four macromolecule classes and their monomers, explain how cells build and break them (dehydration synthesis and hydrolysis), connect each molecule's structure to its job, and use "structure determines function" to predict what a molecule does.

By the end of this week, you can…

Use this as a checklist. If you can do all four out loud, you're ready for the quiz.

• [ ] Name the four macromolecule classes and their building blocks — carbohydrates (monosaccharides), lipids (fatty acids + glycerol; not polymers), proteins (amino acids), nucleic acids (nucleotides).
• [ ] Explain how cells build and break polymers — dehydration synthesis joins monomers (removes water); hydrolysis breaks them apart (adds water).
• [ ] Connect structure to function — starch vs. cellulose; saturated vs. unsaturated fats; the four levels of protein structure; DNA vs. RNA.
• [ ] Use "structure determines function" — explain why one wrong amino acid can break a protein (sickle cell) and why glucose can be both fuel and structure.

What's due this week, and when

Work these in order — each one gets you ready for the next.

Heads-up on the AI tools: you'll use a chatbot to draft and explain, and then you judge its work against what we cover in class. Chatbots routinely call lipids "polymers" (they're not), mix up DNA and RNA building blocks, or scramble the order of protein structure levels. Catching the model is the point — in the tutorial, the assignment, and the lab.

Late policy reminder: 10% off per day late. If life happens, reach out before the deadline — I'd much rather hear from you early.

How to succeed this week

• Lead with the idea, not the jargon. Every term this week is a plain-English idea first (a monomer is just one bead; a polymer is a whole necklace of beads; hydrolysis is just "water-splitting"). The vocabulary comes after the idea clicks.
• Memorize two tiny hooks. "De-Hydration removes water to build; Hydro-lysis adds water to break." And "Structure determines function — shape is everything."
• Build the table once. Make a four-row table (class → monomer → one job → one example) for carbs, lipids, proteins, nucleic acids. Doing it once makes the quiz and the assignment easy.
• Remember the headline lesson: the sequence matters. One swapped amino acid turns normal hemoglobin into sickle-cell hemoglobin. Tiny structural changes have huge functional consequences — that's the whole theme.
• Treat the chatbot as a smart intern, not an oracle. It drafts; you check. That habit is the whole semester in miniature.

You don't need anything from before this course — just last week's idea that life runs on chemistry. Come to class ready to argue about whether a high-protein breakfast really "fills you up" differently than a bagel. See you Tuesday.

(B) Welcome Announcement — Module 3

Release setting: post on the module's start day (offset = 0 days), i.e., Tue Sep 15, 2026 — not before. If your platform won't preserve the scheduled date on import, post this as a draft labeled "Release: Tue Sep 15."

Subject: Welcome to Week 3 — you are made of four molecules 🧬

Hi everyone, and welcome to Week 3 of General Biology I!

Quick warm-up before we start: look at the label on anything in your kitchen. "Total Carbohydrate," "Total Fat," "Protein" — three of biology's four great macromolecule families are printed right there, and the fourth one (nucleic acids) is the DNA inside every cell of the plant or animal that food came from. You are, very literally, built from carbohydrates, lipids, proteins, and nucleic acids — and so is every living thing on Earth.

This week — Biological Macromolecules — we tackle the big question: Life is built from just four kinds of large molecules — so how does the structure of each one decide what it can do? By Friday you'll name the four classes and their building blocks, explain how cells build and break them, and use one powerful idea — structure determines function — to predict what a molecule does.

Three things not to miss:
1. Lecture Tutorial 3 — work through the four macromolecules, dehydration vs. hydrolysis, and protein structure with one approved chatbot (Gemini, Claude, or ChatGPT) and submit the share link. You'll catch the model's mistakes (it loves to call lipids "polymers"), not just trust it. Due Sun Sep 20.
2. Lab 3 ("Testing for Macromolecules in Food"), Quiz 3, Discussion 3, and Assignment 3 also close Sun Sep 20 — the lab is a real food-chemistry test you run at home with iodine, so start early.
3. Open the Start Here page first — it lays out everything in order with due dates.

One promise: this is a course about how living things work, not a glossary to memorize. The whole week comes down to four words — structure determines function — and by Friday you'll see them everywhere, from the bread on your plate to the hemoglobin in your blood.

Bring your curiosity (and maybe a nutrition label) to class on Tuesday.

See you soon,
Prof. Castellano