Presentation on theme: "Photosynthesis in one sentence (5 marks)"— Presentation transcript:
1Photosynthesis in one sentence (5 marks) Photosynthesis is a chemical reactionthat takes place in the chloroplastsin green plant cells, where light energyis used to convert carbon dioxide and water into glucose and oxygen.In your books.Then in another colour annotate any additions.
2Specification LinkDemonstrate an understanding of how limiting factors affect the rate of photosynthesis, including:a) light intensityb) CO2 concentrationc) temperatureInvestigate how factors, including the effect of light intensity, CO2
4Why would farmers spend so much money building this greenhouse?
5What are the limiting factors of photosynthesis? Rate of photosynthesis depends on the growing conditions.Things that slow photosynthesis down are called limiting factors.What are the limiting factors ofphotosynthesis?Farmers want to get the biggest crops possiblefrom their fields and greenhouses. To do this theyneed to provide the best possible conditions forphotosynthesis and growth.
6What is a limiting factor? What is the ideal combination of factors for the maximum rate of photosynthesis?enough lightenough carbon dioxideideal temperature (not too hot or cold)What will happen to the rate of photosynthesis if one of these factors is restricted?The rate of photosynthesis will be below the maximum possible rate.The restricted factor controls how quickly photosynthesis occurs and so limits the rate. It is called the limiting factor.
7Photosynthesis and light – limiting factors How does the amount of light affect the rate of photosynthesis on this labelled graph?1As the amount of light increases, so does the rate. The limiting factor is light.2rate of photosynthesis2Here, increasing the amount of light has no affect on the rate. The limiting factor is now carbon dioxide or temperature.What must be increased for the rate to increase?1light intensity
8Photosynthesis and carbon dioxide – limiting factors How does the amount of carbon dioxide affect the rate of photosynthesis on this labelled graph?As the amount of carbon dioxide goes up, so does the rate. The limiting factor is carbon dioxide.12rate of photosynthesisHere, increasing the amount of carbon dioxide has no affect on the rate. Light or warmth is now the limiting factor.What must be increased for the rate to increase?21concentration ofcarbon dioxide
9Photosynthesis and temperature – limiting factors How does temperature affect the rate of photosynthesis on this labelled graph?1As temperature increases, so does the rate because photosynthetic enzymes work best in the warmth. Here, the limiting factor is temperature.rate of photosynthesis21Most plant enzymes are destroyed at about 45°C. Here, photosynthesis stops and the rate falls to zero.What is the limiting factor?20oCtemperature45oC
11Photosynthesis Investigation In this investigation, you are going to study the photosynthesis of pondweed (Elodea).Using the apparatus shown in the diagram, the photosynthesis can be measured by the number of bubbles of oxygen produced by pondweed in a certain amount of time.clamppondweedsodium hydrogencarbonate solutionbubbles of oxygentest tubebeaker
12Investigating limiting Factors Aim- To see how light intensity can affect the rate of photosynthesis.Distance of LampAmount of Bubbles in 1 MinuteExtension- Write a conclusion for your experiment, if your experiment did not work very well then explain why you think this is and suggest possible improvements.