The Leaf and Photosynthesis Introduction The leaf is

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 H 2 O (l) + 6 CO 2 (g) ---------------> C 6 H 12 O 6 (aq) + 6 O 2 (g) chlorophyll +light

Chloroplasts ¢ Plant cells have organelles called chloroplasts. l l l 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 l 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. l Photosynthesis occurs in chloroplasts • Occurs in the light • Produces O 2 and glucose l 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 C 6 H 12 O 6 + 6 O 2 CO 2 + H 20 + 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. l ¢ That is 100000000000 joules A hydrogen bomb is rated at 4. 2 x 1015 joules l That is 238, 095 hydrogen bombs!

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