PHOTOSYNTHESIS

Learning objectives State where trees come from Write the word and symbol equations for photosynthesis

Learning objectives Identify factors that control the rate of photosynthesis List the fates of glucose

The Fate of Glucose

The Fate of Glucose Some glucose is used to provide the plants immediate energy needs through ______. Glucose is stored in leaves as _____. Glucose is converted into the stable complex sugar _____ before being transported to other parts of the plants. Glucose can also be converted into _____ and stored in seeds Glucose is converted to _____ to make cell walls. Nitrates, taken up by the roots can be used to convert glucose into _____ _____ and then _______.

Factors affecting photosynthesis What is the effect of increasing the light intensity on the rate of photosynthesis? (2) What is the effect of increasing the carbon dioxide concentration on the rate of photosynthesis? (2) Suggest how the rate of photosynthesis can be measured. (2) Which colours of light does a plant use less well for photosynthesis (where it is reflected rather than absorbed). Which colours are reflected. (1) Absorption

Testing leaves for starch ethanol 1 2 4 3 Take a leaf. Heat in boiling water for 1min. Turn off the Bunsen burner. Transfer the leaf to a test tube containing ethanol and place in the hot water as shown. Soften the leaf by transferring it to the beaker of hot water. Place the leaf on a white tile and cover in iodine solution. Turn off the Bunsen burner! 5 Cover the leaf with iodine – black shows that starch is present Wear goggles

Testing leaves for starch Use your observations to answer these questions: What happened to the colour of the ethanol. Suggest the likely boiling point of ethanol: A 78°C B 100°C C 122°C Explain your answer. State the final colour of the leaf. Write a conclusion in one sentence.

Experimental design Fair test? Table one: Design an investigation to show that plants need light for photosynthesis Table two: Design an experiment to find out if plants need carbon dioxide for photosynthesis. (Potassium hydroxide can be used to remove CO2) Table three: Using the aquatic plant, Elodea, design an investigation to study the effects of temperature on the rate of photosynthesis. Fair test?

Structure and function of the leaf Copy and label the diagram of the leaf (2) Suggest a purpose of the waxy cuticle (1) Explain how the air spaces increase the rate of diffusion of carbon dioxide into the leaf (1) Suggest why the pallisade cells are packed close together (1) Deduce with a reason, whether photosynthesis takes place in the upper epidermis (2) State the reactant needed for photosynthesis that is provided by the vein (xylem) (1) State the name of the structure that allows gases to enter and leave the leaf (1) Suggest why plants that grow in the shade often have thicker leaves (1)

Limiting Factors in Photosynthesis

Measuring the rate of photosynthesis Plot the results on a line graph. (5) Explain any pattern that you see in the results. (2) Why was a piece of thick glass placed between the bulb and the plant? (1) How could you test the gas produced to show that it is oxygen? (2) A student set up the same apparatus but using data logging equipment and three sensors. Suggest which three sensors the student used. (3) What are the advantages of using data logging. (2) Distance from lamp (cm) # bubbles per minute 100 6 60 10 40 18 30 24 20 25

Rate limiting factors - Light B C A Between A and B ___________________ is the rate limiting factor. The rate of photosynthesis is ______________ to the light intensity. This is because doubling the light intensity doubles the amount of ____________ produced which is used to fix CO2 in the ____________ cycle. Between B and C, carbon dioxide or ____________ are the rate limiting factors

Rate limiting factors – CO2 B A Between A and B ___________________ is the rate limiting factor. This in an _________________ controlled reaction so that there is more collisions with the _____________ site. Between B and C _____ _______ or ________ is the rate limiting factor.

Rate limiting factors - Temperature B A Between A and B ______________ is the rate limiting factor. This in an ______________ controlled reaction so that there is more collisions with the _____________ site as the carbon dioxide has more _______ energy. At higher temperatures, the enzymes are _________ and the rate of photosynthesis _______.

Photosynthesis

Photosynthesis equation Name the gas produced as a waste product of photosynthesis

Photosynthesis equation Name the pigment used to trap sunlight to split water

Photosynthesis equation Give the formula of Glucose

Photosynthesis equation Name the proteins important in speeding up the reactions of photosynthesis

Photosynthesis equation State the substance to which glucose is converted to store carbohydrate

Photosynthesis equation State the ions taken up by the roots and needed to convert glucose into amino acids and then proteins

Photosynthesis equation State the form in which carbohydrate is transported through the plant as it is more stable

Testing leaves for starch State the substance used to test for starch

Leaf Structure Use the “show me” boards to identify the part of the leaf! Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure Waxy Cuticle Upper Epidermis Lower Epidermis Pallisade Layer Spongy Mesophyll Air Space Stoma Stomata

Leaf Structure

Leaf Structure

Leaf Structure

Leaf Structure

Leaf Structure

Leaf Structure

Leaf Structure

Leaf Structure

Other important plant structures

Other important plant structures

Other important plant structures Used to transport water and minerals

Other important plant structures Used to transport sucrose