The Leaf and Photosynthesis

Introduction The leaf is a collection of tissues working together to carry out photosynthesis. Photo synthesis (light) (putting together) [Putting together with light]

Introduction The purpose of photosynthesis is to create energy Water + Carbon Dioxide --------------------------> Glucose + Oxygen chlorophyll +light 6 H2O (l) + 6 CO2 (g) -----------------------------> C6H12O6 (aq) + 6O2 (g)

Plant cells have organelles called chloroplasts. chloroplasts contain a green pigment chlorophyll cells containing chloroplasts are found in the ground tissue light energy is absorbed by chlorophyll and turned into chemical energy (food for the plant)

Chloroplasts Chloroplasts are suspended in cytoplasm and move inside cells. Cytoplasm behaves like a thick liquid and its movement is termed cytoplasmic streaming.

Chloroplasts Chlorophyll is not the only pigment to capture light energy Accessory pigments help protect the plant and capture the most energy possible

Chloroplasts

Gas Production in Plants Two main reactions that take place in plants and produce gases as products. Photosynthesis occurs in chloroplasts Occurs in the light Produces O2 and glucose Cellular respiration occurs in the cytoplasm and mitochondria Does not need light (except needs products from photosynthesis) Reactions where bonds are broken and release energy Glucose + oxygen  carbon dioxide + water + energy C6H12O6 + 6O2  CO2 + H20 + energy

Photorespiration The two main reactions that take place in plants are so important to each other that we can call everything Photorespiration.

Experiments with Photosynthesis What is an easy way to measure photosynthesis? Watch for a product of photosynthesis – OXYGEN

Something to ponder…. The estimated amount of global energy from photosynthesis is 1.0 x 1021 joules. That is 1000000000000000000000 joules A hydrogen bomb is rated at 4.2 x 1015 joules That is 238,095 hydrogen bombs!

Homework Read p.303 – 308 Do Check and Reflect P.308 # 1,2,3,5,7,8 (DO NOT make the model)