B4 Enzymes: key vocabulary
Twelve key words for IGCSE Co-ordinated Sciences topic B4, with the Vietnamese meaning, how to say each word, a picture and an example. Ends with a test section, and a typing trainer on the site.
Practice
- B4 Enzymes: vocabulary trainer – Learn the 12 words by typing them: from the Vietnamese meaning, from the definition, from the sound and from an example sentence. Words you miss come back; words you know come back later.
Transcript
Welcome. Here are twelve key words for topic B four, enzymes. Listen to each word. Read the Vietnamese meaning. Then look at the picture.
Catalyst. Catalyst. A catalyst speeds up a chemical reaction, and it is not used up. For example, enzymes are biological catalysts.
Enzyme. Enzyme. An enzyme is a protein that works as a biological catalyst. For example, amylase is an enzyme in your saliva.
Protein. Protein. A protein is a large molecule, made from many amino acids joined together. All enzymes are proteins.
Substrate. Substrate. The substrate is the molecule that an enzyme changes. For example, starch is the substrate of amylase.
Active site. Active site. The active site is the part of the enzyme where the substrate fits. Only one shape of substrate fits.
Product. Product. The products are the new molecules made in a reaction. For example, amylase changes starch into maltose.
Complementary. Complementary. Complementary shapes fit together exactly, like a key in a lock. The active site is complementary to its substrate.
Specific. Specific. An enzyme is specific. It works with only one kind of substrate. For example, amylase only breaks down starch.
Optimum. Optimum. The optimum temperature or P H is the one where the enzyme works fastest. Human enzymes work best at about thirty seven degrees Celsius.
Denature. Denature. An enzyme denatures when its shape changes, so the substrate no longer fits. A very high temperature can denature an enzyme.
Kinetic energy. Kinetic energy. Kinetic energy is the energy of movement. Hot molecules have more kinetic energy, so they move faster.
P H. P H. P H is a number that shows how acid or alkaline a solution is. Pure water has a P H of seven. This is neutral.
Now, test yourself. I will show you a picture and the Vietnamese meaning. Say the English word out loud. Then listen, to check.
catalyst.
enzyme.
protein.
substrate.
active site.
product.
complementary.
specific.
optimum.
denature.
kinetic energy.
P H.
Twelve words. Catalyst. Enzyme. Protein. Substrate. Active site. Product. Complementary. Specific. Optimum. Denature. Kinetic energy. And P H. Watch this video again until you know all of them.
More in this series
1:41What are enzymes?
Why the body needs catalysts, what a catalyst does, and why enzymes are proteins that work as biological catalysts. With Vietnamese subtitles. A “Check yourself” section with typed questions is below the video on the site.
1:40How enzymes work
The active site, the substrate, the enzyme-substrate complex and the products; why complementary shapes make an enzyme specific. With Vietnamese subtitles. A “Check yourself” section with typed questions is below the video on the site.
2:14Enzymes: temperature and pH
Why a higher temperature speeds up an enzyme, what the optimum is, and how heat or the wrong pH changes the shape of the active site (denaturation). With Vietnamese subtitles. A “Check yourself” section with typed questions is below the video on the site.
2:16Investigating enzymes: temperature and pH
A practical with amylase, starch and iodine on a spotting tile: how to test the effect of temperature and pH, keep it a fair test and read the results. With Vietnamese subtitles. A “Check yourself” section with typed questions is below the video on the site.
5:30B4 quiz: enzymes
Ten think-time questions on enzymes: catalysts, the active site, specificity, temperature, pH and the amylase practical. Below the video: written workbook questions with model answers.