First 278 words of the document:
Molecules of Life
Cells, DNA and Protein Synthesis
1) Fundamental processes of life take place inside cells. Where do most chemical
reactions take place? Tick the correct option.
b. Cell membrane
2) Select the correct words from the options provided to complete the sentences
Cytoplasm nucleus membrane mitochondria DNA cell energy
3) Circle the correct options in the following sentences.
a. The nucleus/cytoplasm of each cell contains a set of genetic instruction.
b. A DNA molecule forms a single/double helix. The genetic instructions are in
the form of a chemical code made up of three/four bases.
1) Which of the following statements about enzymes are true? Tick the two correct
a. Enzymes are amino acids.
b. Enzymes are proteins.
c. Enzymes act as biological catalysts.
d. Enzymes are only found in washing powders.
e. Enzymes slow down reactions.
1) Fill in the missing word to complete the following sentence.
a. A rise in the temperature increase enzymes activity until the _________
temperature is reached.
2) Briefly explain what happens to enzyme molecules when the temperature becomes
3) At what temperature do the enzymes in your body work best?
4) Other than temperature, what factor affects enzyme activity?
The Lock & Key Mechanism
1) Briefly explain why enzyme molecules have different shapes and functions.
2) At high temperature or extreme pH, the lock and key mechanism of an enzyme
molecule no longer works. Explain why.