Listen to the conversation with an event planner to practise and improve your listening skills. Do the preparation task first. Then listen to the audio and do the exercises. Preparation Transcript Task 1 Task 2
Work–life balance
Listen to a radio interview about maintaining a good work–life balance to practise and improve your listening skills. Do the preparation task first. Then listen to the audio and do the exercises. Preparation Transcript Task 1 Task 2
Meeting an old friend
Listen to the conversation between two old friends to practise and improve your listening skills. Do the preparation task first. Then listen to the audio and do the exercises. Preparation Transcript Task 1 Task 2
Making a decision
Preparation transcript task 1 task 2
The hole in the wall – A2/B1
Joanna is the last fruit seller in her family. When she goes to the capital city to sell her fruits, she discovers something worth more than money. Do the preparation task first. Then read the text and do the exercises. Preparation Reading text Task 1 Task 2
The Main Types of Organic Reactions
Figure 2.1(A) shows raw fruit. The crisp, sharp-tasting fruit becomes soft and sweet when it is cooked. Figure 2.1(B) shows a chemist accelerating the tranformation of ethanol into ethanoic acid, by adding potassiumdichromate and sulfuric acid.What do these reactions have in common? They are both examples of organic reactions. In this section, you will take […]
Enzymes as Catalysts
Metabolic reactions need activation energy to either build or break down molecules. Cells also use special proteins that aid metabolic reactions. These proteins, called enzymes, work by speeding up a chemical reaction. This chemical activity increases the reaction rate, or rate at which a reaction occurs, measured in terms of reactant used or product formed […]
Functional Groups with the C_O Bond
Some of the most interesting and useful organic compounds belong to families you are about to encounter. For example, the sweet taste ofvanilla and the spicy scent of cinnamon have something in common: a carbonyl group. A carbonyl group is composed of a carbon atom doublebonded to an oxygen atom. In this section, you will […]
Enzymes and Energy
In the summer of 2001, a forest fire that had been started by a lightning strike raged through Kootenay National Park in British Columbia. Park officials allowed the fire to progress because the area was scheduled for a prescribed burn. Fires are a natural part of forest ecology and are important in forest regeneration. For […]
Making and Breaking Macromolecules
Large molecules can be broken down to release energy. Alternatively, they can be formed to build cellular structures or store information. In biological systems there are four major types of chemical reactions involved in breaking apart andbuilding molecules: acid-base or neutralization reactions, which transfer hydrogen ions between molecules, redox, or oxidation-reduction reactions, which transfer electrons […]