Photosynthesis Lab: This experiment relates to the unit of photosynthesis. The chemical equation for photosynthesis is 6CO2 + 6H2O + light energy ---> C6H12O6 + 6O2. We used the light bulb as our source of energy and provided water in the beaker. However, one component was still missing and it was the carbon dioxide. Sodium bicarbonate was the source of carbon dioxide that we used. With all three components in place, the spinach leaf disks were able to perform photosynthesis and rise to the surface, as oxygen was released. This was why only the beaker with sodium bicarbonate had disks rising to the surface. Carbon dioxide enters and oxygen exits the leaves through holes called stomata. Photosynthesis consists of two steps: light reactions and dark reactions. The light reactions occur in the thylakoid membranes and the process consists of converting solar energy to ATP and NADPH. The dark reactions occur in the stroma of the chloroplast and the process consists of turning ATP into glucose.
Respiration Lab:This experiment relates to the unit of cellular respiration. The equation for cellular respiration is C6H12O6 + O2 → CO2 + H2O + Energy. Cell respiration consists of glycolysis, Krebs cycle and electron transport chain. During the electron transport chain, oxygen accepts the high energy electrons, which causes a concentration gradient that allows for the production of ATP. Cellular respiration can be demonstrated in a few different ways, but our lab measured how much O2 was consumed by germinating and dry peas to demonstrate cell respiration. During respiration, oxygen is consumed along with glucose, so that carbon dioxide, water and the most important component, ATP can be produced. This is why the gas volume in the respirometer decreased. In our experiment the KOH removed the CO2 produced during cell respiration.
Enzyme Lab:This experiment relates to the unit of biochemistry. Enzymes are biological catalysts that are able to change the rate of a chemical reaction by lowering the activation energy. Enzymes have an optimal temperature that they need to function. If the temperature is increased then there will be more collisions between the molecules and the rate of a reaction will increase. However, if the temperature is higher than the optimum temperature, then the enzyme will denature. In our experiment, the enzyme was boiled for too long and was not able to react due to its denaturation. A substrate is what the enzyme acts on. An active site is the region where the substrate binds to the enzyme. In our experiment, the enzyme catalase reacted with hydrogen peroxide to create water and oxygen as the products.