Hinchingbrooke School Science Department

KS3 Homework Task

Life and Living Processes HW6 – All about dandruff

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Science in the News: All about dandruff

All about dandruff

It is estimated that about half the human population suffers from dandruff, and many people would love to be able to buy an anti-dandruff shampoo that is 100% effective. Now, thanks to research work from an international group of scientists, this may be possible in the future. It is only five years since scientists discovered that most dandruff is caused by a fungus called Malassezia globosa, but they have already cracked the genetic code for the fungus, making it easier to begin development of a shampoo that is totally effective against dandruff.

The fungus, M. globosa, is genetically related to yeast. Although it needs fatty acids to survive, it is unable to make any fatty acids of its own. Instead, it feeds on human sebum, the oily secretion produced by the sebaceous glands in human skin to keep hair and skin waterproof and to stop them becoming dry and brittle. The fungus produces enzymes called lipases to digest the human sebum. As the sebum is broken down it produces a compound called oleic acid, which penetrates the top layer of skin, causing the itchiness and flakiness that we notice as dandruff.

To find out about the genetic code of M. globosa, scientists grew ten litres of the fungus, froze it in liquid nitrogen and then broke it into tiny fragments to extract its DNA – the part from the centre of the cells that contains the genetic information. Scientists hope that this research will also help them to find out about the way other fungi react with humans.

QUESTIONS

1  Use the information in the article to describe one way in which the fungus M. globosa and humans are similar.

2  Many people still think fungi are a type of plant. Describe one way in which M. globosa is different from a green plant.

3  Cells form tissues and tissues form organs. Identify one human tissue and one human organ mentioned in the article.

4  Explain how M. globosa feeds on human sebum. Give as much detail as you can.

5  Discuss how knowing the genetic code for the fungus may help scientists to make a totally effective anti-dandruff shampoo.

Challenge

Design an advertisement for an anti-dandruff shampoo. Explain in your advertisement why using your shampoo just once won’t get rid of the dandruff permanently.