Leaf disk assay lab answers.

Leaf disk assay lab answers Place the disks in a 250-mL side-arm filter flask containing 50 mL of 0. Next, student expose the sunken disks to a bright light. This lab uses the floating disk leaf assay as a vehicle for exploring the action of photosynthesis in plants. Nov 2, 2020 · Activity 2: Leaf Disk Assay Overview Write a hypothesisthat the Leaf Disk Assay is designed to test. ) This was to reduce the impact of random errors. In the spring, Pokeweed may be the best choice. Nov 26, 2022 · According to this experiment procedure leaf disks were taken and left in water, these leaf disks float or not depend upon the overall density of the leaf disk which depends upon the amount of air space getting filled up with CO 2 making it heavier, thus making the leaf disk sink down. Flashcards; Learn; Test; Match; Get a hint. Replace the plunger, being careful not to crush the leaf disks. Essentially, leaf discs are infused with bicarbonate to get them to sink. In this lab, students investigate with the role of light intensity on the rate of photosynthesis. Imagine that you had 1-2 additional class periods available for follow-up experiments with a setup similar to this one. Flashcards The Floating Leaf Disk Assay for Investigating Photosynthesis Brad Williamson Introduction: Trying to find a good, quantitative procedure that students can use for exploring photosynthesis is a challenge. This allows the leaf disks to sink in the experimental solution. This video is about photosynthesis and covers the AP Biology lab "What factors affect the rate of photosynthesis in living leaves". Bre Data Table 2. Name: _____ Period: ____ Biology I Honors – Chapter 7 Photosynthesis Lab The Floating Leaf Disk Assay: A Photosynthesis Investigation PRELAB DISCUSSION Leaf disks float, normally. Repeat this step 2-3 times to get the majority of the disks to sink. Advanced Biology/AP Biology NAME _____ Senegar-Mitchell DATE_____PERIOD_____ Figure 4 Figure 3 8) Put a small volume of sodium To enable screen reader support, press Ctrl+Alt+Z To learn about keyboard shortcuts, press Ctrl+slash Sep 21, 2012 · To address this problem, we developed a leaf disc-based screening assay and infiltration device that allows the rpa level in a whole tobacco plant to be reliably and reproducibly determined. When sodium bicarbonate is added to the water, the bicarbonate ion acts as a carbon source for photosynthesis. You must supply fresh, green leaves for the activity. Explain the changes that occurred within the leaf tissue that allowed the leaf discs to rise to the surface. Leaf disks normally float, however when the air spaces are infiltrated with carbon dioxide, the overall density of the lead disk increases and the leaf disk sinks. What are some additional variables we could test in this Jun 10, 2024 · The independent variables would be, the solution the discs were placed in, how much light they were exposed to, and the size difference of the disc. Part 2: If leaf disks with 5 cm and 1 cm diameters are placed in similar conditions, the 5 cm disks will rise faster. The infiltrating solution includes a small amount of sodium bicarbonate. 1. The y-axis shows the number of floating leaf disks. As you read through the instructions for completing each activity make sure you also: i. When air spaces are infiltrated with solution, the overall density of the leaf disk increases and the disk sinks. As photosynthesis proceeds, the oxygen gas produced will displace the liquid from the intracellular space, and the specific gravity will decrease, and the disks will float. b. The graph must contain the data for all four tubes over the entire length of the experiment (17 minutes). You will use a straw to cut out 10 leaf disks, and may need more than one leaf to make all 10 disks. The differences in the surface area of each of the samples. As photosynthesis proceeds, oxygen collects in the interior of the leaf, causing the leaf disks to float again. The soap wets the hydrophobic surface of the leaf allowing the solution to be drawn into the leaf. For each solution of differing carbon dioxide concentration, there were five cups of solution with ten leaf disks per cup, so there was a total of 50 leaf disks per concentration. Oxygen collects in the leaf as photosynthesis progresses, causing the leaf disks to float again. 5. **Were there any treatments (syringes) without floating disks? a. How much is a tee in the range? Complete table 1 using the data from the experiment. The leaf is composed of layers of cells. This is called the ET50 or effective time for 50 percent of the leaf May 2, 2024 · Once you have done so answer the prelab question BEFORE completing any of the lab's activities. Describe the variable(s) used in the Leaf Disk Assay experiment(s). May 3, 2024 · Remove the plunger of the syringe and place five leaf disks in the syringe barrel. 6CO2 + 6H2O -----> C6H12O6 + 6O2. B (0. The infiltration solution includes water, Sodium bicarbonate (NaHCO 3 ) and some soap. In the floating leaf disc assay, air in the air space is first removed by applying a vacuum to the leaf discs. The dependent variable would be how many discs floated in the syringes in different light sources. When the air spaces are infiltrated with solution the overall density of the leaf disk increases and the disk sinks. All 10 disks rose, but slowly over ~30 minutes. What was the Students investigate photosynthesis using a leaf disk assay. Spinach and other fresh, green leafy vegetables or leaves of Wisconsin Fast Plants® are suitable sources. Jul 27, 2016 · When leaf discs are places in a sodium bicarbonate solution, they will sink to the bottom. " By plotting the percentage of leaf disks floating as a function of time, the time required for 50 percent of the leaf disks to float can be determined (see Figure 3). Data Table 2: Leaf Disk Assay, Light Treatment Time (minutes) 0 5 10 15 20 25 30 35 40 45 50 55 60. The Floating Leaf disk assay is an excellent protocol for students investigating photosynthesis. Replace the plunger being careful not to crush the leaf disks. How do you think the shapes of the two curves would be different if you were measuring actual oxygen production over time rather than just counting the number of leaf disks floating at each time point? 4. Include a brief statement describing why you selected the graphing method you did. 4. Push on the plunger until only a small volume of air and leaf disk remain in the barrel (< 10%). Jun 9, 2023 · The floating leaf disk can be used as an indicator of photosynthesis as the process of photosynthesis releases oxygen which will cause the leaf disk to float. 2% sodium bicarbonate solution. -Hypothesis: Red will be the best one -How it worked: In the leaf-disk assay, all of the components necessary for photosynthesis are present. In one of the cups, add one tablespoon of sodium bicarbonate and mix the solution 4. water Since light acts as an activation energy for photosynthesis the more light the leaf disks get, the faster the rate of photosynthesis. Therefore, the rate ofP/S can be indirectly measured by the rate of rise of the leaf disks. This is because the leaf disks sink in water when the air spaces within them are infiltrated with water, but as photosynthesis occurs and oxygen is produced, the oxygen fills these air spaces and causes the disks to float. technique to create a vacuum. Apr 29, 2022 · Students investigate photosynthesis using a leaf disk assay. Use the correct dimensions and find the quantity of leaf disks. Carefully replace the plunger being careful not to crush the leaf disks. Once you have completed the prelab questions proceed to the activities of the lab within the investigative manual. If any leaf disks float, remove them 3. Having just observed net photosynthesis with floating leaf disks, the leaf disks from the trial presented in problem 1 were placed in the dark to determine the rate of respiration for the leaf disks. The room temperature would be the control, because the cold/hot rates can then be Investigating Photosynthesis - The Floating Leaf Disk Assay. **What does this indicate? 11. Nov 18, 2020 · This number remains constant across trials. As the chloroplasts absorb light they produce oxygen bubbles which eventually cause the leaves to float. What variables were you testing. A red line indicates at what time 50% (5) leaf disks float (at about 11. Leaf disks will naturally float because of the air trapped within the cells, however once the air spaces are intelected with carbon dioxide, the leaf disks density will increase and the leaf disks will sink. 5 3 Leaf Disk Assay Average A and B Light Average C and D Light Average A and B Dark Average C and D Dark Time (minutes) Average # of Disks Floating 1. Students are allowed to answer freely. If the leave leaves are in brighter light condition and a higher concentration of carbon dioxide, then the leaves will rise to the tops of the syringe because with more light and carbon dioxide. Students will work in small groups to design an experiment with one independent variable and test this variable on spinach leaf disks. , In the Leaf Disk Assay experiment, which of the following samples would have the highest rate of photosynthesis? a. This product is one that I have completely modified and expanded so that entry level college b. ) When all the leaf disks have settled to the bottom of the solution, carefully remove the plunger and pour the disks and solution into the cup. 12. In this lab, you will be using leaf disks, to assay the net rate of photosynthesis under various lighting conditions. Pull the plunger out of the syringe. It was rough trying to do the lab today during a 55 min period, only a few groups saw some improvement, but at least my control beakers didn’t rise like yesterday! I’ll probably avoid this lab for a few years until I can get over my frustrations from this week lol. The infiltration solution includes a small amount of Sodium bicarbonate. If the leaf disks did not all sink inside the syringe barrel, repeat steps 7–9 until all of the leaf disks sink to the bottom of the syringe barrel. Type of plant leaf Size of leaf disk Soap amount Depth of solution 1. Use a hole-punch or cork borer to cut leaf disks from a fresh spinach leaf. Oct 9, 2020 · Experimental controls used in the Leaf Disk Assay experiment was the same amount of baking soda solution in each syringe, same environment (light/dark) for each of the syringes, and the presence of soapy water. Activity 2: Leaf Disk Assay Overview 2. 5 minutes). Avoid major veins. Use a hole punch to punch out 20 uniform leaf disks (10 for each cup) Avoid major leaf veins. Ivy seems to provide very consistent results. The punched out leaf disks will initially sink in a test tube of water but will float as photosynthesis occurs Floating leaf disc assay is a method of studying the rate of photosynthesis. beakers were observed for 1 minute and with a direct light source, all 10 leaf disks were able to float. 24%) B In table 1 of the investigative manual, you are given five restriction endonucleases, their recognition sites, and cleavage pattern. When the leaves rise due to the production of oxygen, you know photosynthesis is occuring. Working in groups, half of you should perform the test infiltrating the leaf discs with bicarbonate solution (NaHCO 3) and the other half perform the test infiltrating the leaf discs with water. 3) Infiltrate the leaf disks with sodium bicarbonate solution. Question: Floating Leaf Disk Lab - Discussion Questions. docx from BIOL 101 at University of Louisville. the leaf as photosynthesis progresses, causing the leaf disks to float again. FLDA measures the net rate of photosynthesis by using leaf disks cut from leaves. ii. Small leaf disks will float on water due to the presence of air/gasses in the intercellular spaces of the leaf. One of the suggested lab experiences in the AP Biology classroom is the Floating Leaf Disk Assay or FLDA. Over the years, I have found the floating leaf disk assay technique to be reliable and understandable to students. The equipment and supplies needed are inexpensive, simple, and readily available. 1). 12% solution had the most floating disks average by the 35-minute mark. The biology behind the prodedure: Leaf disks float, normally. Answer to ACTIVITYTable 2: Leaf Disk Assay, Light. 24%) of the total. 4. Utilizing a hole puncher to cut 10-12 uniform leaf disks for each trial. In the next step, a vacuum is used to replace the air pockets within the leaf structure with a baking soda (bicarbonate) solution. Remove the piston or plunger and place the leaf disks into the syringe barrel. The variables used during the leaf disk experiment, was the use of a 0. PK !‚ Ìzš Þ [Content_Types]. Regular desk lamps can be used for light Apr 17, 2023 · Compare the test groups of the Leaf Disk Assay. Some leaf disks will be "early floaters" and oth-ers will be "late floaters. 5 2 2. Holding the syringe tip upward, simultaneously release the syringe plunger and tip to release the vacuum. An empty syringe is used to remove gas from the leaves before the lab. Table 6. xml ¢ ( ´•ËnÂ0 E÷•ú ‘· 1tQU E Ë ©ô Œ= ·ñCöðúûN D Ò ²‰äÌÜ{ =’Ý ®L‘, DílÆzi—%`¥SÚN3ö1~éܳ$¢°J ÎBÆÖ Ùpp}Õ ¯=Ä„Ô6fl†è 8 r FÄÔy°TÉ]0 i ¦Ü ù%¦Ào»Ý;. none available the floating leaf disk assay for investigating photosynthesis trying to find good, quantitative procedure that students can use for exploring The leaf disks will be floating. Figure 2. Leaf disks normally float, however if you remove the air from the air spaces, the overall density of the leaf disk increases, and the leaf disk sinks. The disks should be about 4–6 mm in diameter. Shake or tap the barrel on the lab bench to collect the disks to the bottom (near the opening) of the barrel. 12 bicarbonate solution for the other 2 syringes. Tap the syringe to suspend the leaf disks in the solution. Hold for 10 seconds. 2. The Leaf Disk Assay Homework Questions and Revised Experiment Worksheet must be approved by your lab instructor before running your full experiment. 24%) or a. Data Table 2: Leaf Disk Assay, Light Treatment Jul 26, 2022 · If you have never tried the leaf disk assay, you are missing out on one of the best photosynthesis labs available. When the air spaces in the leaf are infiltrated with baking soda (sodium bicarbonate) solution, the overall density of the leaf disk increases and the disk sinks. 7) Replace the plunger, being careful not to crush the leaf disks. The prototype of the leaf disc infiltration device allows 14 Agrobacterium-mediated infiltration events to be conducted in parallel. (Sample space was 10. Study with Quizlet and memorize flashcards containing terms like The independent variable for lab 7 is (leaf experiment), The dependent variable for today's experiment, The source of CO2 for today's experiment and more. This lab activity demonstrates the process of photosynthesis through the production of oxygen in a plant leaf. How do floating disks correspond to the rate of photosynthesis? Floating disks correspond to the photosynthetic rate because when more disks float it shows that the photosynthesis is occurring. The standard procedures such as counting oxygen bubbles generated by an elodea stem tend to not be “student” proof… The solution will fill in the air spaces in the leaf, causing the disks to sink. The document also contains questions about how variables like light In this lab, leaf disks will be used to assay the rate of photosynthesis under various light conditions. , the intracellular air in the leaf disks is vacuumed off, and the spaces are infiltrated with liquid. Sharp Name: Block: Date: Floating Leaf Disk Assay (for Investigating Photosynthesis) by Brad Williamson The biology behind the procedure: Leaf disks float, normally. Many different plant leaves work for this lab. Push on the plunger until only a small volume of air and leaf disks remain in the barrel. Do not punch through large veins. Close the tip and pull back on the syringe plunger to create a vacuum. Data Table 2: Leaf Disk Assay, Light Treatment Time (minutes) A (0. Save. This will deplete your leaf disks of air (you’ll see it come out!), causing your leaf disks to sink. Propose another experiment that you could do to test the effect of another factor (other than light) on Students use the floating leaf disk method to study the effects of light intensity and CO2 availability on the rate of photosynthesis. If the leaf contains only one pigment, expect to obtain only one color band. In the Guided Investigation, students measure the rate of photosynthesis by counting the number of leaf disks floating at each time. Were there any treatments (syringes) without floating disks? 8. Mar 14, 2024 · Final answer: In the Leaf Disk Assay and related plant experiments, control is maintained over carbon dioxide concentration, light intensity, temperature, and leaf type to ensure that the results are due to these key experimental variables. Bicarbonate ions serve as the carbon source for photosynthesis. An empty syringe is used to remove gas from the leaves b Using a one-hole punch, cut 10 or more uniform leaf disks from a firm leaf, such as spinach or English ivy (avoid the veins). Over the years, I have found the floating leaf disk assay technique to be reliable and understandable to students. It asks students to explain key aspects of the experiment such as the purpose of sodium bicarbonate, the vacuum, and the control trial. Fresh leaf disks will be prepared and then the oxygen and carbon dioxide will be removed from the leaves. (c) Beakers placed on overhead projector differently, thus giving different light intensities. Your solution’s ready to go! Our expert help has broken down your problem into an easy-to-learn solution you can count on. Present your results in a graph. (a) Leaf discs cut from different places in the leaf and may have different thickness (b) May have damaged some leaf discs. What could the rate of leaf disks sinking be correlated to? Explain why. Jun 10, 2019 · Mr. When the students pour the leaf disks into the syringe, it is okay for them to pick up a stray leaf disk so long as they are gentle and make sure not to damage the leaf disk tissue. Push on the plunger until only a small volume of air spaces of leaf disks, first the leaf disks are vacuum infiltrated, i. Why did the leaf disks begin to sink after being placed in the dark? b. Explanation: The leaf disk assay lab is a method used in biology to measure the rate of photosynthesis. The spongy mesophyll layer is normally infused with gases, oxygen and carbon dioxide. (d) More than one leaf disc was used at each solution. Students test the effect of using solutions with and without a carbon source. Then, as photosynthesis continues, oxygen is released into the leaf, which causes the leaf disk to rise. We can use these properties to monitor the rate of photosynthesis when we illuminate leaf disks resting on the bottom of a dish. 6. Pre-lab Leaf Disc Assay for Photosynthesis This is a short instructional video on the procedure for sinking leaf disks in a vacuum using a 10 ml syringe. As photosynthesis takes place, oxygen is released and is trapped under the leaf and causes it to float. Place the disks into a syringe with the sodium bicarbonate solution and create a vacuum, removing the accumulated gas from the air spaces in the disks' mesophyll and replacing it with the sodium bicarbonate solution. Redo the process for submerging the disks into the solution using the plastic syringes 5. Prepare 10 uniform leaf disks for each trial using the hole punch. Study with Quizlet and memorize flashcards containing terms like when light is absorbed by leaf pigments such as chlorophyll a or b, carbon fixation is, 1) energy provided by chloroplasts is used to produce Infiltrate the leaf disks with sodium bicarbonate solution. How can the rate of photosynthesis be measured? 2. 6. Here’s how to do it. Study with Quizlet and memorize flashcards containing terms like leaf disk lab Use the process of photosynthesis to explain what happened in the vidoes experiment?, A description of what happend in your leaf disk experiment?, What conclusions can be drawn from this experiment? In other words, why do you think more leaf disks floated to the surface of the cup containing the sodium bicarbonate Apr 25, 2024 · 12 5 10 15 20 25 30 35 40 45 50 55 60 0 0. Were there any treatments (syringes) without floating disks? May 3, 2021 · Activity 2: Leaf Disk Assay Overview Write a hypothesisthat the Leaf Disk Assay is designed to test. Avoi d the major veins in the leaf ( Fig. Once the students are familiar with the technique they can readily design experiments to answer their own questions about photosynthesis. Explain your experimental design for your experiment. 11. Place each leaf disk into the syringe. e. 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. This document describes an experiment using the floating leaf disk assay (FLDA) to investigate photosynthesis. The overall density of the leaf disk increases, and the leaf disk sinks. Oct 28, 2020 · Activity 2: Leaf Disk Assay Overview Write a hypothesisthat the Leaf Disk Assay is designed to test. 10. The baking soda provides the carbon dioxide that the leaf needs for photosynthesis. A Spinach (Spinacia oleracea) Leaf Disk Assay Introduction Chloroplasts, found in mesophyll cells in leaves are the major sites for photosynthesis, the conversion of light energy and water into usable chemical energy, in the form of carbohydrates (Reece et al. The data collected are based on the number of leaf disks floating at specific time points. However, there's more going on in the leaf than that! the buoyancy of the leaf disks respiration occurs along with photosynthesis (this respiration will consume the oxygen that has accumulated and possibly cause the disks to sink; the measurement tool that can be used to observe these counteracting processes is the floating (or sinking) of the leaf disks Dec 13, 2020 · Hypothesis: Part 1: If leaf disks are placed in two separate bowls, one with a light source and one deprived of light, the leaf disks in the bowl with light will float faster due to photosynthesis producing oxygen. Light and 0. When the air spaces are infiltrated with solution, the overall density of the. Jul 11, 2023 · Make sure the leaves are dry before the students begin punching the leaf disks; otherwise there is a tendency for the leaf disks to stick to the side of the syringe. Dec 17, 2024 · The solution will fill in the air spaces in the leaf, causing the disks to sink. Infiltrate the leaf disks with sodium bicarbonate solution. Exploring Photosynthesis and Plant Pigments Instructor Answer Key Lauren Rhodes Data Activity 1: Plant Pigments Overview Data Table 1: 5) Hole punch 10 uniform leaf disks for each trial using the hole punch. Bicarbonate ion serves as the carbon source for photosynthesis. Leaf, Disk Assay, Light Treatment. With indirect light, only one group’s leaf disks floated but the other’s groups leaf disks didn Jan 19, 2023 · Which leaf disk treatment group contained all that is necessary for photosynthesis? 3. Four experimental floating leaf disc assay tubes containing 10 mL of water and 10 spinach leaves were placed under a light for 17 minutes with varying concentrations of Carbon Dioxide. They should settle to the bottom of the cup (see photos below). What is the source of CO2 in this experiment? 4. Which treatment (syringe) had the most floating leaf disks after 35 minutes? The light treatment with the 0. Jun 16, 2024 · Describe the variable(s) used in the Leaf Disk Assay experiment(s). Continue until all of the disks have sunk in the syringe. . , 2010). The disks are placed in a sodium bicarbonate solution and the time taken for each disk to float, as oxygen is produced through photosynthesis, is recorded. Describe the experimental controls used in the Leaf Disk Assay experiment(s). At first, the leaf disks in the water filled syringe all float because the disks insist small oxygen particles. Variables that can be tested include light synthesis in that leaf disk. However, since this experiment tests the rate of photosynthesis in the leaves, the leaf disks are drawn back with a Experiment 3: Measuring the Rate of Photosynthesis with Floating Leaf Discs. 24%) B For the electronic transition from n = 3 to n = 5 in the hydrogen atom. 2. GTAC Preparing for student leaf disc experiments 1 Using leaf discs to investigate photosynthesis – advice for teachers and laboratory technicians There are three practical activities associated with this resource. Which treatment (syringe) had the most floating leaf disks after 35 minutes? 10. See full list on sciencebuddies. Fill the BS cups Using the leaf disk method, we would test the effect of temperature on the spinach leaves. The leaf disks will be put into a solution of baking soda (sodium bicarbonate, NaHCO 3) and detergent. Also, if the disks rise faster it shows that photosynthesis is occurring faster. If you Jul 11, 2023 · Which leaf disks will carry out photosynthesis and produce O 2? ___ leaf disks in a solution of sodium bicarbonate ___ leaf disks in water (with no sodium bicarbonate) Explain your reasoning. Write a short discussion describing trends in the data: compare the control cups (distilled water) versus the experimental cups (bicarbonate solution) and compare the light versus dark Nov 16, 2016 · Enhanced Document Preview: THE FLOATING LEAF DISK ASSAY LAB REPORT AND ANSWERS. 24%) B 1) What do the Rf values indicate about the relative solubility of the pigments in the experimental solvent? Measuring the Rate of Photosynthesis: A Leaf Disk Assay Leaf Disk Assay Pre-lab Assessment (Part 2) Complete the Homework Questions below and the Revised Experiment Worksheet before you attend lab. This document contains the post-lab questions from a floating leaf disk photosynthesis lab. Control Time (min) # of leaf disks floating 1 0 5 2 10 4 15 9 20 10 25 10 30 10 35 10 40 10 45 10 Light Ambient Light Dark Time (min) # of leaf disks floating Time (min) # of leaf disks floating Time (min) # of leaf disks then PIS can occur in a sunken leaf disk. 5 1 1. Calculate the Rf value for each pigment. Williamson by S. o Part A: Aim – to explore a method that uses leaf discs to measure rate of photosynthesis In this method video, Molly takes us into the lab to perform a leaf disk assay to measure the rate of photosynthesis in spinach leaves. 24 bicarbonate solution for 2 syringes, and a 0. To cut out a disk, cover a fingertip on one hand with part of a leaf, then with the other hand, press the end of a straw against the leaf and your fingertip. If the solution has bicarbonate ions and enough light, the leaf disk will begin to produce sugars and oxygen through the process of photosynthesis. Sep 2, 2019 · Learn how to use leaf disks to measure photosynthesis rates with a simple and reliable technique. 13. 12) Pour the leaf disks and their solution into the appropriately labeled cup. Which treatment (syringe) had the most floating leaf disks after 35 minutes? 7. (1 point) The leaf disk exposed to light will photosynthesize, the leaf disk in the dark will be unable to photosynthesize due to lack of light. After 10, 12, 13, 15, 16, and 17 minutes in the dark, the number of leaf disks floating were 10, 9, 7, 5, 4, and 3, respectively. Sep 12, 2022 · What is a leaf disk assay? In the floating leaf disk assay, 10 or more leaf disk samples are punched out of a leaf. View this video (and m Activity 2: Leaf Disk Assay Overview. A (0. Materials and method: • Leaves • Hole-punch • 2 x 10mL syringe • Distilled H 2 O • bright sunlight or lamp Leaf disks normally float, however when the air spaces are infiltrated with carbon dioxide, the overall density of the lead disk increases and the leaf disk sinks. This lab is commonly cal In other words, the buoyancy of the leaf disk is actually an indirect measurement of the NET rate of photosynthesis occurring in the leaf tissue. e. What happens because cellular respiration is also taking place? The oxygen consumed because of photosynthesis is an indirect measurement of the net rate of photosynthesis. This process helps remove air from the spongy mesophyll layer of the leaf disks, causing them to sink in the solution. Below is a graphical representation of the data. You can test your predictions by seeing whether the leaf disks float as a result of producing O 2 when placed in sodium bicarbonate solution vs. Exploring Photosynthesis and Plant PigmentsExploring Photosynthesis and Plant Pigments© 2023 Carolina Biological Supply Company© 2023 Carolina Biological Supply Company (minutes) Time A (0%) B (0%) Average ofA and B C (0%) D (0%) Average of Cand D Science; Biology; Biology questions and answers; Activity 2Write a hypothesis that the Leaf Disk Assay is designed to test. a. Infiltrate the leaf disks with solution. Holding a finger over the syringe opening, draw back on the plunger to create a vacuum. Leaf disks float as oxygen gas is produced during photosynthesis. Pull the plunger out of the syringe and put 10 leaf disks in the syringe barrel. The light source provides light energy, the solution provides water, and sodium bicarbonate provides dissolved CO2. The ET50 value of the "Light" group = 5 Leafs (50%) at 2 minutes. **Discuss your conclusions regarding your two solution. • Pull a small volume of sodium bicarbonate solution into the syringe. 1 / 16. Floating Leaf Disk Assay In this investigation, you will use a system that measures the accumulation of oxygen in the leaf. Apr 24, 2019 · After 14 minutes, the leaf disks were moved into the dark and the number of floating disks was recorded every minute. Generally speaking, a leaf floats (due to the many intercellular spaces used for exchange of gases). investigate rate of photosynthesis. In the Leaf Disk Assay, the hypothesis is that the rate of photosynthesis can be measured by measuring oxygen production. The differences in solubility and adsorption of substances by partitioning them between a mobile and a stationary phase. The length of time it takes for leaf disks to float again is a measure of the net rate of photosynthesis. The speed and number of floating disk becomes a measure of the rate of photosynthesis. Floating Leaf Disks Lab (Photosynthesis) The solution will fill in the air spaces in the leaf, causing the disks to sink. leaf disk increases and the disk sinks. 3) What is the source of CO2 in this experiment? 4) Why do leaf disks float when they receive light, but not when placed in the dark? Your answer should include specific reactions of photosynthesis, 5) What do you predict would happen if both leaf disk groups received light, but one received water and the other received water and sodium 7. This process is shown in Figure 2. Leaf discs cut from a fresh leaf normally float in water because there is air in the air space of the leaf. Mr. Leaf disks float, normally. Apr 18, 2022 · Activity 2 1. Pour 100mL of water into two cups 3. (If I test 4 syringes in light and in the dark, the study with light will have more floating disks because the photosynthetic rate would be fastest. 3. If a syringe containing plants is left in the light then it will have the most floating disks because its photosynthetic rate is the fastest in the light. Find materials, procedure, tips and variations for this lab activity. Do this by removing the piston or plunger and placing the leaf disks into the syringe barrel. Without the use of extensive laboratory equipment, the rate of photosynthesis can be determined indirectly by conducting a floating leaf disk assay to measure the rate of oxygen production (Figure 2). The cups were then exposed to light for 20 minutes, and the number of disks floating in each cup was measured every minute. Study with Quizlet and memorize flashcards containing terms like why can the floating leaf disk assay be used to measure photosynthesis?, what product of photosynthesis is measured?, why is et50 for infiltrated disks kept in the absence of light, equal to infinity? and more. Compare the test groups of the Leaf Disk Assay. The ET50 value of the "Control" group = 5 Leafs (50%) at 11 minutes. Make sure they are all in the water. Push on the plunger until only a small volume Mar 12, 2025 · leaf disk lab. How is adding baking soda to the water adding Carbon Dioxide?3. Try not to include the major veins in the leaf disks (Fig. How are we measuring the rate of photosynthesis in this experiment. Jul 19, 2022 · According to this experiment procedure leaf disks were taken and left in water, these leaf disks float or not depend upon the overall density of the leaf disk which depends upon the amount of air space getting filled up with CO 2 making it heavier, thus making the leaf disk sink down. Remove the plunger of the syringe and carefully transfer leaf disks in the barrel. **How do floating disks correspond to the rate of photosynthesis? 12. Andersen shows you how to sink leaf chads in preparation for the AP Biology photosynthesis lab. In the second activity, an investigation will be conducted that examines the rate of photosynthesis in various light conditions and CO 2. Leaves (or disks cut from leaves) will normally float in water because of these gases. The Floating Leaf Disk Lab The biology behind the procedure: Leaf disks float, normally. org In this lab, you will be using leaf disks, to assay the net rate of photosynthesis under various lighting conditions. • Leaf age • Leaf variegation • Role of respiration in plants along with photosynthesis — measuring gross photosynthesis • Size of leaf disk • Depth of bicarbonate solution • Methods of cutting disks • Leaf disk overlap • Soap amount • How many times can the procedure be repeated with the same disks? • How long can the disks General Biology Adapted from B. Cork the d. If the air is evacuated from the tissue, the disks will sink. Remove the plunger of the syringe and place five leaf disks in the syringe barrel. Analyzing In which tube did all (or most) of the leaf disks float f Nov 16, 2016 · The ET50 value is the time required for 50% of the leaf disks to float. The activity calls for fresh spinach leaves, but other leaf types may be tried. Experimental Question: What factors affect the rate of photosynthesis? Pre-lab Questions - these should be completed before the scheduled lab. As P/S proceeds, 02 accumulates in the air spaces of the spongy mesophyll, and the leaf disk will once again become buoyant and rise in a column of water. Why do leaf disks float when they receive light, but not when placed in the dark? Your answer should include specific reactions of photosynthesis. Nov 26, 2023 · The leaf disk assay lab provides answers related to the effectiveness of different test solutions on the rate of photosynthesis. Nov 26, 2011 · The leaf disks are gradually going to create oxygen that will change the buoyancy – causing the disks to float. That way, the leaf disk can absorb the solution. Disk Assay to Quantify Photosynthetic Rates In this lab exercise you will quantify photosynthetic rates in spinach leaves using a floating disk assay. Materials Syringes, 5 cc or Larger Desk Lamps with 18- to 23-W Fluorescent or LED Bulbs Plastic Straws […] (You may need to tap on the plunger to release the bubbles in order to make all the leaf disks sink. The soap breaks down the molecules on the leaf’s surface (because the leaf repels the solution) to allow the bicarbonate solution to penetrate the cells. Take the photos of your experiments in each activity as Data Table 3: Leaf Disk Assay Mar 14, 2021 · Activity 2: Leaf Disk Assay Overview 3. Based on the data collected in the lab, when we put the light pathway cups in the dark, the number of floating leaf disks decreased as the time decreased. Chromatography of Plant Pigments Band # Distance from origin (mm) Band Color / Identification 1 0 white 2 1 white 3 1 white 4 1 white Solvent front 0 Activity 2 Leaf Disk Assay Overview Read and complete Activity 2 Leaf Disk Assay Overview . Sep 14, 2018 · Lab Report for Exploring Photosynthesis and Plant Pigments Lab Dillon Wages Lab Date : 11 Leaf Disk Assay, 2010 Name: ANSWER KEY (p 19SS CHEM40C Chapter 18 Dec 17, 2024 · The solution will fill in the air spaces in the leaf, causing the disks to sink. In order to test it, we would prepare the syringes in solutions of water at five different temperatures: 2 in the cold range, 1 at room temperature, and 2 in the hot range. Be sure to use a clear syringe so you can collect data throughout the lab. The. This causes the leaf discs to sink in water. Students are asked to define carbon fixation and explain how photosynthesis causes leaves to float. concentrations. Study with Quizlet and memorize flashcards containing terms like Photosynthesis, Carbon fixation, 6CO2 + 6H2O -> C6H12O6 + 6 CO2 and more. Nov 10, 2023 · answer any questions found in the post lab questions for each activity. When sodium bicarbonate is added to the water, the bicarbonate ion acts as a carbon source for photosynthesis causing the leaf disks to sink. Sep 21, 2020 · 3. Photosynthesis at Work Question: If the leaf disks are treated in a way you know increases the net rate of 7 Floating Disks: An Investigation of Photosynthesis Post-Lab Questions and Analysis Directions: After completing the Floating Disks lab, answer the questions below. Write a hypothesis that the Leaf Disk Assay is designed to test. 9. leaf disks into the syringe barrel. Post-Lab Questions. Aug 19, 2008 · This activity will allow students to measure the rate at which the photosynthesis process occurs. Punch only through the large, homogenous, flat parts of the leaf. In the floating leaf disk assay, 10 or more leaf disk samples are punched out of a leaf. 24% sodium bicarbonate b. 8. 3) 6) Remove the plunger of the syringe and place your leaf disks in the syringe barrel. The baking soda is a source of carbon, and the detergent acts as a wetting agent that makes it easier for the View lab 5. Chemical equation for photosynthesis. When these intercellular spaces are instead filled with solution, the density of the leaf increases and it sinks. mjcsi vasxgz rlbmfduz fpic asyqnqe jeazap ncdv tido sidllos quxiwue