Genes and Health Think about GCSE – What do you know about Genes/Genetics? What do these words make you think of? What affects do our Genes have on health? Title: Topic 2: Genes and Health

Understand what is covered in topic 2 and begin to consider some key points in the topic Identify the issues posed people who carry the CF gene Be able to explain the properties of a gas exchange system Understand how cystic fibrosis effects the lungs of sufferers

Journey through topic  How changes in DNA can result in genetic disease such as CF including process of DNA replication  Symptoms of CF  Focus on structure of lungs and importance of gaseous exchange – in particular surface area to volume ratio  Study cell membrane structure and how substances move across membranes  To explain how faults arise in the cell membrane surface of CF sufferer – learn how genes code for proteins, how proteins are made and how their function is dependent on their structure  Role of genes in inheritance  Genetic screening and gene therapy may help people with CF  Ethical views of new technology

If we have a child – will it have CF? If the child does have CF, how will It effect its life and our own? How is CF inherited? What are the chances of any child inheriting the condition? Can genetic screening help? What treatments are available? What does the future hold? What research may develop in the future?

CF is a common genetic disease CF is a common genetic disease CF affects the respiratory, digestive and reproductive systems CF affects the respiratory, digestive and reproductive systems

Normal Lungs Layer of mucus coating tubes of lungs Produced by goblet cells Traps dust and micro organisms Removed by cilia on epithelial cells Lungs of a Cystic Fibrosis Sufferer Drier mucus than normal Sticky and difficult to remove by cilia cells Builds up in the airways

Increases Chance of Lung Infections Reduces Gas Exchange

Gaseous exchange must Be rapid so there is Enough oxygen reaching All the body’s respiring cells

cell-diffusion-across-the-cell-membrane- video.htm

 Large surface area  Numerous number of capillaries around alveoli  Thin walls between alveoli and capillaries

Ficks Law The three properties of an effective gas exchange system Rate of diffusion α SA X Difference in Conc Thickness of surface Large SA Big difference in concentration Thin walls

O2O2 O2O2 O2O2 O2O2 O2O2 O2O2 O2O2 O2O2 O2O2 O2O2 CO 2 Alveoli Capillary Draw what happens next in terms of diffusion - draw as many pictures as you think it takes to explain it Draw another picture show how diffusion could Be increased Draw a final picture showing the factor which reduces gas exchange Write down Fick’s Law of diffusion

REVIEW One thing about CF that you would like to know more about 2 effects that CF has on lungs 3 properties of an effective gas exchange system

Find out how to calculate: Volume Surface Area Surface area: volume ratio You will not be able to do the practical without it!!!!!!!!!!!!!!!!!!!!