Photosynthesis Lab Debrief

Leaf Discs and Infiltration Why would a leaf disc usually float when placed in a liquid solution? The air that is in the air spaces in the leaf make it buoyant (float) What will happen after infiltrate the leaf disc? It will sink because all the air has been removed and replaced with fluid

Infiltration (continued) If sodium bicarbonate is used to infiltrate leaf discs, what will happen when they are placed under a light source? They will float when enough O2 is produced to displace the fluid in the air spaces

Data Collection: ET50

ET50 and rate of photosynthesis What will happen to the ET50 as the rate of photosynthesis goes up? It will go down (less time for the discs to float)

Rate vs. ET50 Inverse relationship

Rate vs. 1/ET50 This shows a positive slope for increasing rate of photosynthesis

Extension: covering up the discs What will happen if the discs are then covered up (no light)? All graphs taken without permission from http://www.elbiology.com/labtools/Leafdisk.html

Why? Discs start to sink because they are also doing cellular respiration O2 is being used up