Week 4 — Readings & Resources · Cell Structure & Function

Course: Introduction to Biology — General Biology I (BIOL 101) · Silver Oak University (fictional sample) · Prof. Castellano
Objective covered: Objective 3 — Describe cell structure, the organelles and their functions, the plasma membrane and transport, and why cells stay small (surface-area-to-volume).

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: 2–3 short videos + 2 short readings, grouped by the ideas from the lecture, plus one optional free interactive. 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 two kinds of cells (prokaryote vs. eukaryote) → ② the organelle tour → ③ the membrane & transport → ④ why cells stay small (surface-area-to-volume).

A habit to start now: before you trust any biology claim — in these resources or anywhere — ask the questions from class: Does this get the structure→function right? Which way does the water actually move? Did the arithmetic on the ratio check out?

① Two Kinds of Cells · Prokaryotic vs. Eukaryotic

Maps to Lecture Segment 2. Every cell is either a prokaryote (no nucleus, DNA loose) or a eukaryote (true nucleus, membrane-bound organelles) — but all cells share a membrane, cytoplasm, DNA, and ribosomes.

Video — "Prokaryotic vs. Eukaryotic Cells (Updated)" (Amoeba Sisters)
🔗 https://www.youtube.com/watch?v=Pxujitlv8wc
Why it earns the click: a friendly ~5.5-minute side-by-side of the two cell types — the modern cell theory, the three domains, and exactly the similarities-and-differences table we built on the board. Locks in "the nucleus is the dividing line."
⏱ ~5 min

Reading — "Prokaryotic Cells" (OpenStax Biology 2e, §4.2)
🔗 https://openstax.org/books/biology-2e/pages/4-2-prokaryotic-cells
Why it's assigned: the cleanest plain-language version of what all cells share, what makes a prokaryote, the relative sizes of cells, and the surface-area-to-volume reason cells must stay small (it works the cube example we did — 6:1 then 3:1) — free to read online, no account needed.
⏱ ~10 min

② The Organelle Tour · Structure → Function

Maps to Lecture Segment 3. Each organelle has a job, and its structure fits that function — the nucleus directs, ribosomes build, the ER and Golgi make and ship, mitochondria power, lysosomes recycle. Plant cells have mitochondria too.

Video — "Introduction to Cells: The Grand Cell Tour" (Amoeba Sisters)
🔗 https://www.youtube.com/watch?v=8IlzKri08kk
Why it earns the click: a guided tour of the organelles and their functions, including the plant-vs-animal-cell comparison and the path a protein takes out of the cell — the same factory tour we ran in class.
⏱ ~9 min

Video (alternative) — "Eukaryopolis – The City of Animal Cells: Crash Course Biology #4" (CrashCourse)
🔗 https://www.youtube.com/watch?v=cj8dDTHGJBY
Why it earns the click: Hank walks the animal cell like a city — membrane, ER, ribosomes, Golgi, lysosomes, nucleus, mitochondria — fast, funny, and a great second pass if the organelles aren't sticking yet.
⏱ ~11 min

Reading — "Eukaryotic Cells" (OpenStax Biology 2e, §4.3)
🔗 https://openstax.org/books/biology-2e/pages/4-3-eukaryotic-cells
Why it's assigned: the organelle-by-organelle reference, built around "form follows function," with the animal-vs-plant-cell figures and the microvilli example that ties surface area to absorption. Skim the parts your videos rushed.
⏱ ~10 min

③ The Membrane & Transport · Diffusion, Osmosis, Active Transport

Maps to Lecture Segments 5–6. The plasma membrane is a fluid-mosaic gate. Passive transport (diffusion, osmosis, facilitated) is downhill and free; active transport is uphill and costs ATP. Osmosis moves water, toward the saltier side.

Video — "Cell Transport" (Amoeba Sisters)
🔗 https://www.youtube.com/watch?v=Ptmlvtei8hw
Why it earns the click: the membrane's role in homeostasis, simple and facilitated diffusion, and active transport (with endocytosis/exocytosis) — the same passive-vs-active split we drew, and it nails the concentration-gradient idea.
⏱ ~8 min

Reading — "Passive Transport" (OpenStax Biology 2e, §5.2)
🔗 https://openstax.org/books/biology-2e/pages/5-2-passive-transport
Why it's assigned: the clearest written treatment of diffusion, osmosis, and tonicity — hypotonic, hypertonic, isotonic — with the red-blood-cell figure (swell, normal, shrivel) and the wilting-plant example. This is the section to read if the prefixes keep flipping on you.
⏱ ~10 min

Optional one-stop references (free online)

• Khan Academy — Structure of a cell. A free unit with short articles and videos on prokaryotes vs. eukaryotes, the organelles, and membranes/transport. A good place to return to all term.
  🔗 https://www.khanacademy.org/science/biology/structure-of-a-cell
• Learn.Genetics (University of Utah) — "Cell Size and Scale." A beautiful interactive: zoom from a coffee bean down to a carbon atom and see how tiny cells really are — the perfect companion to this week's surface-area-to-volume idea (and the Week 4 lab).
  🔗 https://learn.genetics.utah.edu/content/cells/scale/

Pick-one quick path (≈18 min total)

In a hurry? Do exactly these and you'll be ready for the quiz:
1. Watch "Prokaryotic vs. Eukaryotic Cells" + "Introduction to Cells: The Grand Cell Tour" (groups ①–②).
2. Watch "Cell Transport" (group ③), and skim the surface-area-to-volume part of "Prokaryotic Cells" (group ①/④).

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.