Photosystems I and Ii Summary

Measuring the Rate Oxygen Production using an Oxygen Electrode Chamber in Photosynthesis of Spinacia oleracea with Varying Light Intensities

The preparation for the experiment started by gathering the solutions of enzyme Peroxidase, substrate hydrogen peroxide, the indicator guaiacol and distilled water. Two small spectrometer tubes and three large test tubes with numbered labels. In addition, one test tube rack, one pipet pump and a box of kimwipes were also gathered. Before the experiment, the spectrometer must be set up to use by flipping the power switch to on. Following, the machine was warmed up for 10 minutes and the filter lever was moved to the left. In addition, I set the wavelength to 500 nm with the wavelength control knob. Before the experiment, I had to create the blank solution by pipetting 0.1 ml of guaiacol, 1.0 ml of turnip extract and 8.9 ml water into tube #1. Following the creation of the blank, a control 2% solution was created.

The purpose of this lab is to observe the effect of white, green, and dark light on a photosynthetic plant using a volumeter and followed by the calculation of the net oxygen production using different wavelengths color of white and green light, and also the calculation of oxygen consumption under a dark environment, and finally the calculation of the gross oxygen production.

L. Relate the functions of the antenna complex and the reaction center in a chloroplast

In photosynthesis H+ ions are vital in the production of the energy source that is ATP, which is used in several metabolic processes, such as respiration. The photolysis of water produces H+ ions, electrons and O2. The excited electrons lose energy as they move along the electron transport chain, this energy is used to transport the H+ ions (protons) in to the thylakoid, which causes a higher concentration of H+ than there is in the stroma, thus causing a proton gradient across the membrane. The H+ then proceed to move down the concentration gradient into the stroma via the enzyme ATP synthase. The energy from this process is called chemiosmosis and combines ADP with inorganic phosphate (Pi) to form ATP. Light energy is then absorbed by photosystem I (PS I) which excites the electrons to a higher energy level. These electrons are transferred to NADP with H+ ions from the stroma to form reduced NADP. The whole of this process is

The process of photosynthesis, by which light energy is used to convert inorganic compounds into organic substances with the release of oxygen, may be the most important biological event sustaining life (Keir et al. 2017). In the light-dependent reactions, the chloroplasts of a plant use the pigment chlorophyll to convert light energy into chemical energy. This energy is used to split water and produce oxygen (Eller et al. 2015). The energy is later used in the light independent reactions, where carbon dioxide (CO2) undergoes carbon fixation with the aid of enzyme rubisco, because it catalyses both carboxylation and oxygenation reactions and most of responses of photosynthesis to light, CO2, and temperature (John Evans 2013).

Photosynthesis is a food making process for algae and plants. The photosynthesis process rate varies from different wavelengths and intensities of light. This lab will evaluate the optimal wavelengths and degrees of intensity during photosynthesis when chloroplast is exposed to light. The mixtures of DCPIP with water, PO4 buffer, and chloroplast will be prepared in a number of cuvettes. The cuvettes were tested individually at different wavelengths and intensities to find the optimal rate of photosynthesis by using a spectrophotometer, measuring the greatest change in absorbance. From this experiment, two data charts and four graphs were obtained. The hypothesis was set from graphs obtained in this lab, and the optimal reaction

In light reactions, light is absorbed by chlorophyll in the thylakoid membrane and energizes the electrons. ATP is created from ADP and P. NADP accepts electrons and turns in to NADPH, which is energy. Once the light reactions have taken place, the light-independent, or ‘dark’ reaction occurs in the stroma, where CO2 is converted to sugar. The

Chloroplasts are organized structures for photosynthesis and they consist of three distinct membranes. They are outer membrane, inner membrane and thylakoid membranes. Photo complexes, photosynthetic proteins are assemble in the thylakoid membrane network. These three membranes separate three spaces in the chloroplast, namely, intermembrane space, stroma and thylakoid lumen. Protein targeting and translocation into chloroplast is therefore of broad interest.

The light-dependent reactions produce oxygen gas and convert ADP and NADP+ into energy and NADHP. The light-dependent reactions occur in the thylakoid.

This experiment was performed using the procedure from the Photosynthesis in Leaf Disks Lab. First using a #3

During photosynthesis, the section that is light dependent stage is in the thylakoids in the Mitochondria of a plant cell, while the light independent stage is in the stroma of the Mitochondria of a plant cell, specifically named the Calvin cycle. The light dependent and light independent stage work together to perform photosynthesis. The light independent gives ATP and NADPH to the light independent stage. In return, the light independent stage gives the light dependent stage NADP+ and ADP. The light dependent stage works in the thylakoids of the Mitochondria in a plant cell. It starts off by light energy being absorbed by photosystem II,

Experiment 1 Question: The main question that was addressed in the first experiment (Parts I and II) was which cell fraction had the most photosystem activity, which would be proportional to the number of chloroplasts present in the cell fraction. Photosystem activity is proportional to the number of chloroplasts since the photosystems are active in the thylakoid membranes of chloroplasts (Leicht and mcallister 2016). The amount of photosystem activity would be seen in the relative absorbance values for each cell fraction under the given light conditions. The absorbance would decrease as the DCIP electron acceptor (which is blue when oxidized) gets reduced (which is colorless). “The amount of color change is expected to be proportional to the number of functional photosystems, which in turn is proportional to the number of intact chloroplasts” (Leicht and mcallister 2016). We knew that chloroplasts were required for photosystem activity, but we

     Photosynthesis has a two-stage performance before plants produce the two products they are known to produce. These stages are Photosystem I and II. Photosystem II is dependant on light reactions for energy which causes the electrons to be react and be transferred to Photosystem II. The electrons are transported through the Photosystem II electron transport system, however some energy is used to drive ATP synthesis. Meanwhile, light is being absorbed by the Photosystem I, which causes the electrons to react. This process sends the electrons to the Photosystem I transport system where some energy is released as electrons travel through the electron transport system and is captured as NADPH. When this process is completed oxygen is released from the plant and glucose has been

     To metabolic pathways involved in photosynthesis are light reaction and dark reaction. The first stage of the photosynthetic system is the light-dependent reaction, which converts solar energy into chemical energy. Light absorbed by chlorophyll or other photosynthetic pigments is used to drive a transfer of electrons and hydrogen from water to and acceptor called NADP , reducing it to the form of NADPH by adding a pair of electrons and a single proton. The water or some other donor molecule is split in the process. The light reaction also generates ADP, a process called photophosphorylation. ATP is a versatile source of chemical energy used in most biological processes. The light reaction produces no carbohydrates such as sugars.