Take Brief Notes
W.3.8
Read the text, then answer the questions.
Why Bread Rises
Yeast is alive. It is a fungus, and each grain of dried yeast holds millions of cells waiting for water. Add warm water and the cells wake up. They begin to feed on the sugars in the flour. As they feed, they give off carbon dioxide gas. The gas cannot escape, because kneading the dough has built a stretchy web of gluten that traps it. Thousands of tiny bubbles form, and the dough swells. In the oven, two things happen. The trapped gas expands in the heat, so the loaf rises further. Then the heat kills the yeast and sets the gluten, and the bubbles are locked in place. That is why bread has holes in it.
- 1. The author says the loaf rises further in the oven. What reason is given?
- 2. How is this text organised?
- 3. What traps the gas in the dough?
- 4. What kind of living thing is yeast?
How a Windmill Grinds Flour
A windmill turns moving air into turning stone. The sails are set at a slight angle. Because of that angle, wind pushing on them cannot pass straight through, so it pushes them round instead. The sails turn a horizontal shaft. A large wooden gear on that shaft meshes with a smaller one on an upright shaft, which turns the millstones below. Because the smaller gear has fewer teeth, it spins faster than the sails do. Four turns of the sails can mean twenty turns of the stone. The grain falls between two stones. The top stone turns; the bottom one does not. The grain is crushed between them, and flour comes out at the edge.
- 1. The author says the stone spins faster than the sails. What reason is given?
- 2. Where does the flour come out?
- 3. How is this text organised?
- 4. How are the sails set?
LessonPrint · W.3.8 · Set 25 · free to copy for classroom use