Photosynthesis

Where do we get our energy from? How do we release energy from food? Food +Carbon dioxide +Oxygen+ ENERGYWater Respiration (Glucose)

Plants can’t eat… …what do they release energy from?

Photosynthesis In order to get energy plants must make their own food. The do this by the process of photosynthesis.

Why is this plant so unhealthy? What do plants need to make food?

Photosynthesis Water + Carbon dioxideOxygen + Glucose sunlight

In light plants can photosynthesise and respire. In dark plants can only respire. Food +Carbon dioxide +Oxygen+ ENERGYWater (Glucose) Respiration + FoodCarbon dioxide + Oxygen Water Sunlight (Glucose) Photosynthesis

What factors might affect how much photosynthesis a plant can do?

100%71%50% 25% 12.5% 6.3% 0%0%

Photosynthesis Investigations Can use algae beads or Cabomba.

Algae Bead Investigation In a small beaker (mix together): 2.5cm 3 sodium alginate 5cm 3 algal cells Then, Put some calcium chloride in another beaker Position calcium chloride under an open-ended syringe Pour algal mixture into syringe Rinse the algal balls with distilled water

Algae Bead Investigation 1.Collect: Algae beads 7 mini jars spatula / spoon One of each type of filter 2.In each mini jar add 15 algae beads 3.Add bicarbonate indicator to each mini jar 4.Slot a filter onto each mini jar 5.Place mini jars in light bank or on window ledge

Cabomba Investigation

Step 1 In pairs add 5 fronds of Cabomba to each tube.

Step 2 Fill each tube with indicator. Put the lid on a write your initials.

Step 3 Slide a different light filter on each tube, leave 1 with nothing on... Clearly label your tubes! There is a top and bottom to the filters.

What does the indicator show?

Photosynthesis Increasing CO 2 in indicator Decreasing CO 2 in indicator Less Photosynthesis took place More Photosynthesis took place What do your results tell you?

What effect does light intensity have on photosynthesis? Each filter lets through a different amount of light. In other words we are changing the light intensity reaching the algae. 100%71%50%25%12.5%6.3%0%

What does more CO 2 tell us about the rate of photosynthesis? Day Plants photosynthesise and respire Oxygen Carbon dioxide Oxygen Respiration Photosynthesis

What does more CO 2 tell us about the rate of photosynthesis? Night Plants only respire Oxygen Carbon dioxide Respiration

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