Lab Report 1 Biology Photosynthesis 6e1y1t

Sarthak Patel Biol 1108 Section 001 2/23/15 Lab Report 1: Photosynthesis Lab Effect of ______ on ___ and Introduction: Photosynthesis and cellular respiration are important biochemical life processes that involve a series of catalytic reactions. Photoautotrophs are able to convert of inorganic carbon dioxide to organic, high-energy glucose using light energy in their chloroplasts (EEB dept. 2014). In comparison cellular respiration happens in the cytoplasm of bacteria and in the mitochondria of eukaryotic cells where high energy glucose is broken down in order to capture energy as ATP molecules. This experiment will seek to examine rate of photosynthesis and respiration in a spinach leaf tissue using leaf disks. We predict that under light conditions, the leaf discs will display photosynthesis and under dark conditions the leaf discs will show cellular respiration. In addition, we hypothesize that if the lighting apparatus is moved farther away from the leaf discs then the rate of photosynthesis will be observably slower. -- what is biological reason? Photosynthesis Light Energy

6CO2 + 6H2O ⇒ C6H12O6 + 6O2

Cellular Respiration C6H12O6 + 6O2 ⇒ 6CO2 + 6H2O + ATP

Materials and Methods: Spinach leaves were punched out in order to create leaf discs that were initially placed in a syringe barrel with the plunger removed. The plunger was replaced and slowly pushed towards the tip in order to remove air after which 3 cc of 0.2% bicarbonate/detergent solution was added to the syringe as a CO2 source for the leaf discs. A vacuum was created inside the syringe and the discs were allowed to sink and then poured into a plastic cup containing bicarbonate solution. The cup with the discs was placed under a light source and the number of disks floating at the surface was recorded every minute until all discs are floating. As photosynthesis occurs in the presence of CO2 and light, oxygen will be produced and discs will expand and rise. After all discs have risen the cup will be placed in a dark cabinet, and the rate at which the leaf discs sink will be used to measure cellular respiration. In the control experiment, the plastic cup consisted of distilled water in order to represent the absence of CO2 and the rate of photosynthesis was measured. In addition, a second experiment was performed where the lighting apparatus was heightened and placed farther away from the leaf discs and the effect on the rate of photosynthesis was analyzed.

PSET50:

Figure 1. Observed floating discs out of 15 in the presence and absence of light.

Figure 2. Observed floating discs out of 19 in distilled water and a heightened light source.

Module 1: The Abosrpiton Spectra of Plant Pigments Module 3: Floating Leaf Disk Assay Results:

Discussion: References: need 2 Department of Ecology and Evolutionary Biology, University of Connecticut. Biology 1108 Laboratory Manual, 2014 edition, University of Connecticut, Storrs, Connecticut.