Abstract The practical was carried out to investigate the various forms of plant cell metabolism. The process of photosynthesis and fermentation was the main focus of the practical exercise. The first practice was on photosynthesis (the hill reaction) and variations in light intensity, light wavelength and inhibiting substances were investigated. The second practical focused on starch synthesis “the Dark reaction,” this is the light-independent stage of photosynthesis. In this experiment, the conversion of sugars to starch for storage is shown in the third experiment, fermentation was studied using fresh and boiled potato extracts and the yeast cell ( Saccaromyces cerevisiae) . The role of the fermentation process to provide energy for the yeast cells is shown in this experiment. The results were tabulated, analysed and discussed to understand the practical. Introduction Cellular metabolism is a complex process that occurs both in plants and animals. “The various processes that take place are catalysed by respective enzymes involved.” (Kamau, 145) Much of the metabolic activities are dedicated to generating energy for cellular activity. “Plants in particular manufacture food by the process of photosynthesis.” (Nelson 3) In the process carbon is converted to organic compounds using the sunlight, the organic compounds, which are mainly in form of sugars, are utilized as food by plants and animals. Photosynthesis takes place in chloroplasts; a lot of research has been done in the past to determine the different factors (for example, Light intensity and wavelength) that affect photosynthesis. Part of the present study aims at ascertaining the factors that play a role in photosynthesis. Following photosynthesis, a biosynthetic process called the “the dark reaction” takes place in the matrix of the stroma, the process leads to the formation of other forms of sugar. (Allen, 145) Another metabolic process is fermentation. This is the conversion of carbohydrates to energy with the production of alcohols and acids. It involves transferring electrons obtained from the breakdown of nutrients back to molecules of the same nutrients. Fermentation is utilized to break down sugars and release energy among other products. In order to confirm the above cell metabolic activities, three experiments were set up: experiment one to investigate the hill reaction and effects due to variations in light intensity, wavelength and photosynthesis inhibiting chemical. Experiment two investigates the dark reaction phase of photosynthesis where by the energy is stored and can be retrieved when there is a shortage and experiment three investigate the process of fermentation. Materials and Method Materials   * Spectrophotometer   * Spectrophotometer cuvettes   * Phosphate buffer (pH6.5)   * Chloroplast suspension   * Sodium hydrosulfite   * Distilled water   * Wrapping foil   * DCMU   * 10nM glucose-1-phosphate   * Starch solution   * 1M KH2PO4   * Fresh potato extract   * Boiled potato extract   * 10% glucose   * 2% yeast suspension   * 2 Conical flasks   * Syringes Procedure Experiment 1: The hill reaction Freshly boiled chloroplast suspension was obtained and allowed to return to room temperature. Four clean spectrophotometer cuvettes were obtained and labelled 1-4. 3.0 ml of Phosphate