Study Sheet · Week 6

Cells & Energy

The tiny machines that keep every living thing running

A study sheet is a single page you can read in one sitting: the topic headings, the words you must remember, and a short checklist to prove you have done the work. Fill in the notes below in your own words — copying them out is half the revision.

The Cell at a Glance

Every living thing is built from cells. A cell is a tiny bag of jelly wrapped in a thin skin, and inside that bag a set of small parts each do one job. Learn the parts, and the rest of this unit becomes much easier to follow.

Cell membrane
The outer skin. It holds the cell together and decides what may pass in or out.
Cytoplasm
The jelly inside, where most of the cell's work happens.
Nucleus
The control room. It stores the instructions the cell needs to copy itself.

Energy and the Mitochondria

Cells need energy to grow, repair and move. That energy comes from food, but food has to be broken down first. The mitochondria are the parts that do this, which is why they are often called the power stations of the cell.

  • Sugar is split apart inside the mitochondria.
  • The energy released is stored in a ready-to-use form.
  • Busy cells, such as muscle, hold many mitochondria.

Movement Across Membranes

The membrane is not a solid wall; it is picky about what it lets through. Water drifts freely, while larger or charged particles need a doorway. This quiet movement is happening in you right now, without any effort at all.

Diffusion
Particles spreading from a crowded place to a quiet one.
Osmosis
Water moving through a membrane to even things out.

Review Checklist

Tick each box once you can do it without looking at your notes. Untick anything you had to peek at, and come back to it tomorrow.

  • Name the three main parts of a cell.
  • Explain what the nucleus is for in one sentence.
  • Say why muscle cells hold many mitochondria.
  • Tell the difference between diffusion and osmosis.
  • Draw a labelled cell from memory.

How to Use This Template

Open index.html in Notepad and type over the words to make the sheet your own. The colours, spacing and fonts all live in style.css. To add a subject, copy one whole <section class="topic"> block; to add a tick-box, copy one <li> in the checklist. Select Print and the page tidies itself into a clean black-and-white sheet. That is the whole workflow: edit, save, refresh.