Week 2 — Readings & Resources · The Chemistry of Life

Course: Introduction to Biology — General Biology I (BIOL 101) · Silver Oak University (fictional sample) · Prof. Castellano
Objective covered: Objective 2 — Explain the chemistry that underlies life: atoms and bonds, water's emergent properties, and pH/acids/bases/buffers.

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. 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 atoms & bonds → ② water's emergent properties → ③ pH, acids, bases & buffers.

A habit to start now: before you trust any chemistry claim — in these resources or anywhere — ask the questions from class: Is this cohesion or adhesion? Does lower pH mean more or less acidic? Is each pH step really a tenfold jump?

① Atoms, Bonds & the Building Blocks of Life

Maps to Lecture Segments 2–3. Matter is built from atoms (protons, neutrons, electrons); the elements of life are CHNOPS; and atoms join by covalent (shared electrons), ionic (transferred electrons), or hydrogen bonds (weak attractions).

Reading — "Atoms, Isotopes, Ions, and Molecules: The Building Blocks" (OpenStax Biology 2e, §2.1)
🔗 https://openstax.org/books/biology-2e/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks
Why it's assigned: the cleanest plain-language version of what an atom is, the elements that make up living things, and how covalent, ionic, and hydrogen bonds form — exactly the Segment 2–3 material — free to read online, no account needed. (Read the sections on chemical bonds; you can skim the isotope math.)
⏱ ~12 min

Reference — Khan Academy: "Chemistry of life" unit (Biology)
🔗 https://www.khanacademy.org/science/biology/chemistry-of-life
Why it earns the click: a free unit of short articles and videos covering atoms, bonds, water, and pH — the whole week in one place. Use the "Elements and atoms" and "Chemical bonds" lessons for this group, and come back to it for ② and ③.
⏱ ~10 min (pick a lesson or two)

② Water's Emergent Properties

Maps to Lecture Segment 4. The heart of the week: water is polar, so its molecules form hydrogen bonds, and from that one fact come cohesion, adhesion, surface tension, high specific heat, floating ice, and water's power as the universal solvent.

Video — "Properties of Water" (Amoeba Sisters)
🔗 https://www.youtube.com/watch?v=3jwAGWky98c
Why it earns the click: a friendly ~6-minute tour of the exact properties we built on the board — polarity and hydrogen bonds (0:49–1:35), adhesion and cohesion (1:35), surface tension (2:32), water as a solvent (2:57), ice as an insulating layer (3:31), and high specific heat (4:44). It makes the same point we did: every property traces back to those hydrogen bonds.
⏱ ~6 min

Reading — "Water" (OpenStax Biology 2e, §2.2)
🔗 https://openstax.org/books/biology-2e/pages/2-2-water
Why it's assigned: the plain-language version of water's polarity, cohesion/adhesion, high heat capacity, solvent properties, and floating ice — and it carries straight into pH, acids, bases, and buffers (group ③ below), so this single page covers most of the week. Free to read online.
⏱ ~12 min

③ pH, Acids, Bases & Buffers

Maps to Lecture Segments 5–6. The number that runs through all of biology: pH measures hydrogen-ion concentration; acids are below 7, bases above 7; each step is a 10× change; and buffers resist pH change to keep blood and cells alive.

Video — "pH Scale" (Amoeba Sisters · #Shorts)
🔗 https://www.youtube.com/shorts/N77hpLpkxkw
Why it earns the click: a one-minute refresher on what the pH scale measures (hydrogen-ion concentration) and which end is acidic vs. basic — a quick, memorable companion to the pH section of the reading. (Then make sure you can do the 10×-per-step math from class — the video keeps it simple.)
⏱ ~1 min

Reading — "Acids, bases, pH, and buffers" (Khan Academy, Biology)
🔗 https://www.khanacademy.org/science/biology/water-acids-and-bases/acids-bases-and-ph/a/acids-bases-ph-and-bufffers
Why it's assigned: the best short explanation of what makes something an acid or a base, what the pH scale measures, why each unit is a tenfold change in H⁺, and how the blood buffer system keeps your pH steady — the Segment 5–6 material in one readable article.
⏱ ~10 min

Optional one-stop references (free online)

• OpenStax Biology 2e — Chapter 2 ("The Chemical Foundation of Life"). The full free chapter if you want the complete picture (§2.1 atoms & bonds, §2.2 water & pH, §2.3 carbon — carbon previews next week).
  🔗 https://openstax.org/books/biology-2e/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks
• Khan Academy — "Water, acids, and bases." A free unit zeroing in on water's properties and the pH scale, with short videos and practice questions. Great for an extra rep before the quiz.
  🔗 https://www.khanacademy.org/science/biology/water-acids-and-bases

Pick-one quick path (≈19 min total)

In a hurry? Do exactly these and you'll be ready for the quiz:
1. Watch "Properties of Water" (group ②).
2. Watch "pH Scale" (group ③), then read the pH/buffers section of "Acids, bases, pH, and buffers" (group ③) and make sure you can do the 10×-per-step math.

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.