Chapter 3 / 7 short lessons
Biological molecules
Connect molecules to their roles, read food-test evidence and explain how enzymes work.
G3 Combined Biology / K327 / K328 / 2027 syllabus
What do you think?
An enzyme reaction becomes slow in the cold. Must the enzyme be permanently damaged?
Lessons
0 of 7 marked as readCarbohydrates, fats and proteins
State the main roles of carbohydrates, fats and proteins.
About 4 minBuilding larger molecules
Match each large molecule to the smaller units used to synthesise it.
About 5 minTesting for starch and reducing sugars
Describe iodine and Benedict's tests and interpret their observations accurately.
About 5 minTesting for proteins and fats
Describe biuret and ethanol emulsion tests, including valid observations and controls.
About 4 minHow enzymes speed up reactions
Explain enzyme specificity using the active site, enzyme-substrate complex and lock-and-key model.
About 5 minTemperature and enzyme activity
Explain temperature effects and compare rates using a controlled enzyme investigation.
About 6 minpH and enzyme activity
Explain pH effects and plan a fair comparison of enzyme activity at different pH values.
About 5 minWhat you will be able to do
- Match major molecules to roles and building units.
- Interpret all four food tests.
- Explain enzyme specificity and investigate temperature and pH.