Week 3 — Readings & Resources · Cell Structure, Function & Membrane Transport

Course: Anatomy & Physiology I (BIOL 2301 + BIOL 2101) · Silver Oak University (fictional sample) · Prof. Navarro
Objective covered: Objective 2 — Describe the plasma membrane and the major organelles, and explain passive, active, and bulk transport — including osmosis and tonicity.

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 + 1 interactive simulation, grouped by the ideas from the lecture. 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 40–50 minutes if you do everything, far less if you pick one per group.

Order that matches the lecture: ① the membrane & the organelles → ② passive transport & osmosis → ③ tonicity, active transport & the Na⁺/K⁺ pump.

A habit to start now: before you trust any A&P claim — in these resources, in a chatbot, or anywhere — ask the questions from class: Which way does water move (toward more solute)? Is this transport passive or active? Is the outside bath lower or higher than the cell's ~300 mOsm?

① The Plasma Membrane & the Organelles

Maps to Lecture Segments 2–3. The cell's border is a selectively permeable phospholipid bilayer; inside, each organelle has one main job — structure → function.

Video — "Introduction to Cells: The Grand Cell Tour" (Amoeba Sisters)
🔗 https://www.youtube.com/watch?v=8IlzKri08kk
Why it earns the click: a clear, friendly tour of the cell that names the organelles and their functions in order — cell membrane, nucleus, ER, ribosomes, Golgi, mitochondria, lysosomes — exactly our organelle slide. Watch the "tour inside the cell" section (≈ 3:11) for the structure→function pairings.
⏱ ~8 min

Reading — "Anatomy and Physiology 2e," §3.2 The Cytoplasm and Cellular Organelles (OpenStax)
🔗 https://openstax.org/books/anatomy-and-physiology-2e/pages/3-2-the-cytoplasm-and-cellular-organelles
Why it's assigned: the cleanest plain-language statement of each organelle's structure and function — the endomembrane system (ER, Golgi, lysosomes), mitochondria (ATP), and the cytoskeleton — a free online textbook page, no account needed. (Use the "Previous" link for §3.1 on the cell membrane.)
⏱ ~12 min

② Passive Transport & Osmosis

Maps to Lecture Segment 4. Passive transport runs downhill with no ATP — simple diffusion, facilitated diffusion, and osmosis (water moving toward more solute).

Reading — "Diffusion and passive transport" (Khan Academy, Biology)
🔗 https://www.khanacademy.org/science/biology/membranes-and-transport/passive-transport/a/diffusion-and-passive-transport
Why it's assigned: a short article that walks through diffusion, facilitated diffusion, and osmosis with clear figures — exactly the passive-transport bucket from class, including why "water follows solute." (The surrounding unit, Membranes and transport, covers active transport too.)
⏱ ~10 min

Interactive — PhET "Membrane Channels" simulation (free, no download)
🔗 https://phet.colorado.edu/en/simulations/membrane-channels
Why it earns the click: a free, browser-based simulation where you insert channels into a membrane and watch particles diffuse down their gradient through channel proteins. You'll use it in Lab 3 to predict which way things move; spend five minutes now adding a channel and watching the two sides even out.
⏱ ~5 min (browse)

③ Tonicity, Active Transport & the Na⁺/K⁺ Pump

Maps to Lecture Segments 5–6. Compare the outside bath to the cell (~300 mOsm) to predict swell/shrink/same; active transport (the Na⁺/K⁺ pump, 3 out/2 in) moves things uphill using ATP.

Reading — "Anatomy and Physiology 2e," §3.1 The Cell Membrane (OpenStax)
🔗 https://openstax.org/books/anatomy-and-physiology-2e/pages/3-1-the-cell-membrane
Why it's assigned: the single best reference for membrane structure, selective permeability, osmosis, tonicity (isotonic/hypotonic/hypertonic), active transport, and the Na⁺/K⁺ pump — with the red-blood-cell tonicity figure. Skim the figures on tonicity; this is the page to keep open during the lab.
⏱ ~12 min

Video — Anatomy & Physiology playlist (CrashCourse)
🔗 https://www.youtube.com/playlist?list=PL8dPuuaLjXtOAKed_MxxWBNaPno5h3Zs8
Why it earns the click: Hank Green's 47-episode A&P series; the early episodes cover the cell and its membrane transport in an energetic ~10-minute format. A good change of pace if a reading isn't landing. (Browse to the cell/membrane episodes near the start of the playlist.)
⏱ ~10 min

Optional one-stop references (free online)

• Khan Academy — Membranes and transport. A free unit with short articles and videos on the membrane, passive vs. active transport, osmosis, and tonicity. A good place to return to.
  🔗 https://www.khanacademy.org/science/biology/membranes-and-transport
• GetBodySmart — interactive A&P tutorials. Clean, labeled, interactive diagrams; handy when you want to drill cell structures and names.
  🔗 https://www.getbodysmart.com/

Pick-one quick path (≈22 min total)

In a hurry? Do exactly these two and you'll be ready for the quiz:
1. Watch "Introduction to Cells: The Grand Cell Tour" (the organelle pairings, group ①).
2. Skim OpenStax §3.1 The Cell Membrane (membrane, osmosis, tonicity, and the Na⁺/K⁺ pump — the heart of the quiz).

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