Results may vary. The syringes without a light source should not have floating leaf disks. Click to see full answer Considering this, did any leaf disks float in the dark treatment? When you put floating leaf disks in the dark, they will eventually sink. Without light energy, no photosynthesis will occur, so no more O2 gas will be produced.
What happens when you put floating leaf disks in the dark?
When you put floating leaf disks in the dark, they will eventually sink. Without light energy, no photosynthesis will occur, so no more O 2 gas will be produced. However, respiration continues in the dark, so the disks will use the accumulated O 2 gas. They will also produce CO 2 gas during respiration,...
Can floating leaf disks show photosynthesis in action?
Floating Leaf Disks for Observing and Investigating Photosynthesis Introduction: This experiment is designed to show photosynthesis in action. More advanced students will be able to use the technique to answer their own questions about photosynthesis.
Why do the leaf disks sink in this experiment?
If the air is evacuated from the tissue, the disks will sink. We can use these properties to monitor the rate of photosynthesis when we illuminate leaf disks resting on the bottom of a dish. Why is it necessary to cause the leaf disks to sink in this experiment?
How long does it take for Leaf Disks to float?
After 7 minutes the first leaf disk floats, after 11 minutes 4 leaf disks float, at 12 minutes 7 leaf disks float, at 13 minutes 8 leaf disks float, and after 14 minutes all 10 leaf disks float. A red line indicates at what time 50% (5) leaf disks float (at about 11.5 minutes). This time is labeled Effective Time ET50. Figure 3.
Why would leaf disks float even in the dark treatment?
Results: In the light, you should expect to see the disks in the control solution (water) stay on the bottom, but the disks in the treatment solution (baking soda) should begin to rise as they use the CO2 to undergo photosynthesis and produce oxygen bubbles. The bubbles should cause the disks to float.
What caused the leaf disks to float?
Bicarbonate ion serves as the carbon source for photosynthesis. As photosynthesis proceeds oxygen is released into the interior of the leaf which changes the buoyancy--causing the disks to rise.
Why did the leaf discs float during the photosynthesis experiment?
The biology behind the procedure: Bicarbonate ion serves as the carbon source for photosynthesis. As photosynthesis proceeds oxygen is released into the interior of the leaf, which changes the buoyancy--causing the disks to rise.
What do floating leaf discs indicate about photosynthesis What does it mean for them to float slower faster?
Floating disks correspond to the photosynthetic rate because when more disks float it shows that the photosynthesis is occurring. Also, if the disks rise faster it shows that photosynthesis is occurring faster. If the disks do not float it shows that photosynthesis is not happening or that is happening very slowly.
Did any leaf discs float in the dark treatment?
When you put floating leaf disks in the dark, they will eventually sink. Without light energy, no photosynthesis will occur, so no more O2 gas will be produced.
Why do leaf disks float when they receive light but not when placed in the dark?
The leaf disks intake carbon dioxide from a baking soda solution and sink to the bottom of a cup of water. When exposed to light, the disks use carbon dioxide and water to produce oxygen and glucose. Oxygen released from the leaves forms tiny bubbles that cause the leaves to float.
What is the effect of darkness on photosynthesis explain?
Nighttime. Photosynthesis stops when the sun sets. During night hours, most plants switch from photosynthesis to the opposite process, respiration, in which carbon dioxide and water are produced rather than consumed.
What process is unable to occur in leaf disks in the dark?
The leaves deprived of light cannot initiate photosynthesis and produce oxygen, and thus do not float. There are two parts of photosynthesis: the light reaction and the dark reaction.
What is floating leaf disk lab?
In the floating leaf disk assay, 10 or more leaf disk samples are punched out of a leaf. In the next step, a vacuum is used to replace the air pockets within the leaf structure with a baking soda (bicarbonate) solution. The baking soda provides the carbon dioxide that the leaf needs for photosynthesis.
What do you think would happen if the leaf disks were boiled prior to this experiment?
If we were to boil the leaf disks, what kind of results would you expect? Explain. All the leaf disks would sink because there would be no space for gases. The proteins would denature and not function properly, so photosynthesis would not be able to occur.
Why in the baseline activity are the floating leaf disks placed in a solution that contains sodium bicarbonate?
Why, in this experiment, are the floating leaf disks placed in a solution that contains sodium bicarbonate? The bicarbonate ions serve as the carbon source for photosynthesis.
How long does it take for a leaf to float?
The y-axis shows the number of floating leaf disks. After 7 minutes the first leaf disk floats, after 11 minutes 4 leaf disks float, at 12 minutes 7 leaf disks float, at 13 minutes 8 leaf disks float, and after 14 minutes all 10 leaf disks float.
What happens to the oxygen in a leaf?
As the plant leaf photosynthesizes, oxygen is produced that accumulates as oxygen gas bubbles on the outside of the leaf disk. The attached oxygen gas changes the buoyancy of the leaf disk and once enough oxygen has been produced, the leaf disk will rise to the surface of the baking soda solution.
How to make a leaf syringe?
Remove the plunger from the syringe and pour all 10 leaf disks with the solution into a fresh, clear plastic cup. Fill the cup with baking soda solution up to a depth of about 3 cm. Label this cup "1.". Repeat steps 3–8 twice more, with 10 leaf disks each, to prepare the other two cups.
What is the solution used to replace air pockets in a leaf?
In the next step, a vacuum is used to replace the air pockets within the leaf structure with a baking soda (bicarbonate) solution. The baking soda provides the carbon dioxide that the leaf needs for photosynthesis. The leaf disks are then sunk in the baking soda solution and exposed to light.
How to get carbon dioxide out of ivy leaves?
Punch out 30 leaf disks from the spinach or ivy leaves using the hole puncher or a straw. Avoid cutting through major leaf veins. Remove the plunger of the syringe and place 10 leaf disks into the syringe barrel.
What is the reaction that affects the speed of photosynthesis?
Similarly, the concentration of carbon dioxide—another reactant in photosynthesis—affects how fast photosynthesis can occur. Temperature also plays a significant role, as photosynthesis is an enzyme-mediated reaction. This is because at high temperatures, enzymes can get damaged and thus become inactivated.
What is the process of photosynthesis?
Photosynthesis is a multi-step, enzyme -mediated process that converts light energy into chemical energy. During photosynthesis, plant cells use light energy (such as light emitted from the sun), water (H 2 O), and carbon dioxide (CO 2) as reactants to produce sugar molecules (C 6 H 12 O 6) and oxygen (O 2) (Figure 1):
What is the solution in the mesophyll of leaf disks?
In this experiment, the spaces in the spongy mesophyll of leaf disks are filled with a sodium bicarbonate solution , which causes them to sink in the solution. The leaf disks are then exposed to light and observations are made as the cells undergo photosynthesis.
What is the process of photosynthesis?
Photosynthesis is a process in which plants convert light energy (sunlight) into usable chemical energy (carbohydrates). Photosynthesis involves two simultaneous processes: the light dependent reactions and the light independent reactions (Calvin Cycle). In the light dependent reactions, light energy is captured and converted to high energy ATP and NADPH molecules. In the light independent reactionsthese high-energy molecules are used to reduce CO2 and eventually form carbohydrates such as glucose.