Lesson Starter With reference to the graph, explain the effect of temperature on enzymes

Learning Intention To be able to understand and explain the process of peristalsis To identify the site of churning and explain the process

Show me board questions: Recap What is the role of teeth in digestion? What are the 4 types of teeth and their jobs? Explain the position of teeth in carnivores, herbivores and omnivores Why is saliva important in digestion? What enzyme is present in saliva? What does enzyme specificity mean? What is the effect of low temp on enzymes? Why? What is the effect of high temperatures on enzymes? Why? What is meant by optimum temperature? What is the name of the tube that connects the the mouth to the stomach?

If we stand on our head and eat, will food still reach our stomach? Discuss.. If we stand on our head and eat, will food still reach our stomach?

Swallowing What does it feel like when you swallow? Oesophagus- muscular tube PERISTALSIS

What do you think our MUSCLES in our OESOPHAGUS do when we swallow? Peristalsis activity Collect a rubber tube, marble and washing up liquid The aim is to get the marble from one side of the tube to the other. Try without the washing up liquid and then with. Which is easier? Why? The marble represents the food, the tube is the oesophagus.. What do you think our MUSCLES in our OESOPHAGUS do when we swallow?

Peristalsis (copy) http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/common_systems/digestionrev2.shtml Saliva provides LUBRICATION to allow the food to be swallowed easier. Peristalsis is a series of INVOLUNTARY wave-like muscle contractions that moves food along the digestive tract. The muscles BEHIND the food CONTRACTS and squeeze the food along. The muscles INFRONT of the food RELAX to allow the food to pass through.

Inside the stomach Muscular bag- longitudinal/ latitudinal Chemicals - Important that the food comes into contact with the chemicals

What else is this action doing to the food? Task Collect a bag, food and “digestive juices” Add the food and digestive juices to the bag.. How do you mix it all together to ensure that the food is coming into contact with the chemicals? What else is this action doing to the food?

The stomach (copy) The stomach is a muscular bag which contracts in order to mix partially digested food in with digestive juices (acid, bile, enzymes). The muscular contractions also help to PHYSICALLY break down the food. The muscular contractions are referred to as CHURNING.

Summarise today’s lesson into 3 bullet points End Task Summarise today’s lesson into 3 bullet points