Biology Plant Transport Systems Photosynthesis Photosynthesis Learning Intentions

Biology Plant Transport Systems & Photosynthesis

Photosynthesis Learning Intentions 1. 2. 3. 4. What is Photosynthesis? Leaf structure and function What are the plant transport systems? How many stages are there in photosynthesis? 5. What happens in each stage of photosynthesis? 6. How can photosynthesis be measured? 7. What are the factors that can limit photosynthesis?

1. What is Photosynthesis? Photosynthesis is a series of enzyme controlled reactions which allow green plants to make their own food Photosynthesis changes light energy from the sun into chemical energy in the form of ATP The word equation for photosynthesis is: Light. Energy Photosynthesis video Stand Deliver

2. 1 Leaf Structure Waxy Cuticle Upper Epidermis Vein (Xylem & Phloem) Palisade Mesophyll Spongy Mesophyy Air space Stoma Guard Cells

2. 2 Leaf Structure and Function Leaf Part Function Waxy Cuticle Waterproof outer layer Epidermis Protective outer layer Xylem Transports Water Phloem Transports Glucose (Sugar) Palisade Mesophyll Contain lots of chloroplasts for photosynthesis Spongy Mesophyll Loosely arranged for gas exchange Moist air space Moist to allow gases to dissolve Stoma Allows Carbon Dioxide in and Oxygen out of leaf Guard Cells Open and close stomata

3. 1 Plant Transport Systems (WATER) Transport of Water Transpiration is when water moves from the roots up to the leaves of a plant Water is needed by the plant for photosynthesis Water moves from a region of high water concentration (in the soil) to a region of lower water concentration (in the root hairs) by osmosis Water travels up the stem of a plant in non-living xylem vessels to the leaves Xylem Vessels are hollow and are made of rings of lignin Practical: Tomato Sauce and Celery

3. 2 Plant Transport Systems (GLUCOSE) Transport of Glucose (Sugar) Glucose is made in the leaves by Photosynthesis Glucose can travel from the Leaves to all other parts of the plant in Phloem vessels are living cells made of sieve tubes and companion cells

3. 3 Plant Transport Systems Root Diagram of Xylem and Phloem Stem Diagram of Xylem and Phloem Plant Transport Video Clip (2: 59)

3. 4 Plant Transport Systems (Gas Exchange) (Turgid) Practical: See Stomata (Flaccid) Photosynthesis Animation

3. 5 Gas exchange in leaf Cuticle Upper Epidermis Palisade Xylem Mesophyll Vascular Phloem Spongy Mesophyll Lower Epidermis Carbon Dioxide gas enters Stoma Guard Cells Oxygen gas leaves the leaf Bundle

4. Stages of Photosynthesis grana Photosynthesis occurs in a chloroplast of a leaf Stage 1 – Photolysis Occurs in the grana of a Chloroplast Stage 2 – Carbon Fixation Occurs in the stroma of a Chloroplast stroma A Chloroplast

5. 1 Stage 1 - Photolysis PHOTOLYSIS Photolysis is the first stage of Photosynthesis Light Energy from the sun is trapped by chlorophyll in chloroplasts. The Light Energy is used to split water into Hydrogen and Oxygen. Light Energy The Light Energy is converted into Chemical Energy in the form of ATP The 3 products of photolysis are Oxygen, ATP and Hydrogen Water Oxygen is released to the air (as a by-product) ATP and Hydrogen are passed onto the second stage of Photosynthesis (Carbon Fixation) Hydrogen Oxygen ADP + Pi → ATP

5. 2 Stage 2 – Carbon Fixation Stage 2 - Carbon fixation ATP and Hydrogen (from Photolysis) are used with carbon dioxide to make the product glucose ATP Glucose can be: 1. Converted to an energy source (in respiration) 2. Stored as Starch 3. Made into Cellulose (for cell walls) Hydrogen Carbon Dioxide Carbon Fixation Glucose Practical: Testing leaves for starch

5. 3 Summary Stage 1 & Stage 2 Photosynthesis Stage 1 st Stage 2 nd Stage Name Photolysis Carbon Fixation Where in chloroplast? Grana Stroma Requires Light Yes No Requires Chlorophyll Yes No Raw Materials Water Carbon Dioxide (from soil via roots) (from air via stomata) Products Hydrogen Oxygen ATP Glucose

6. Measuring Photosynthesis Count number of oxygen bubbles Upside down test tube Water Upside down funnel Cabomba

7. Limiting Factors The factors that limit the rate of photosynthesis are: Light Intensity Light Energy is an essential factor needed for to split Water into Hydrogen + Oxygen Carbon Dioxide Concentration Carbon Dioxide is a raw material needed to help make Glucose Temperature Photosynthesis is controlled by enzymes. Enzymes work too slowly at low temperatures, and become denatured at too high temperatures *If the rate of photosynthesis decreases, the rate of cell growth decreases

8. Photosynthesis & Industry Photosynthesis Carbon Dioxide + Water light energy Oxygen + Glucose chlorophyll Limiting Factors Temperature Light Intensity Carbon Dioxide Concentration Control of Limiting Factors Heaters Supplementary Lighting Heaters which burn paraffin to increase carbon dioxide M&S Letter

Photosynthesis Activities • • • Water Transport Practical – Celery/Flowers/Tomato Sauce Stoma Pore Practical – Nail Varnish/Germaline New Skin Rate of Photosynthesis Practical Limiting Factors and Photosynthesis Practical - Design Matching Cards (See N 4/5 Drawer) True and False Statements – Revision Compare and Contrast Photosynthesis and Respiration Photosynthesis song Textbook Questions Homework Past Paper Questions Quick Quiz