Cycles in Biology

563 Words3 Pages
CYCLES IN BIOLOGY Biology has a multitude of cycles of which 4 I have studied. A cycle is a series of repeating events in the same order. A cycle is a continuous event in which as long as all the components are present will keep cycling. The 4 stages I’ve studied so far are: * The Calvin Cycle (Ecological cycle) * The Kreb Cycle (Biochemical cycle) * The Nitrogen Cycle (Ecological Cycle) * The Carbon Cycle (Ecological Cycle ) Cycles such as these are important to the survival of many organisms and their ecosystems. Many ecosystems depend on cycles such as these. Without these cycles ecosystems and survival of some species could not be sustained. The Calvin cycle is a cycle involved in the light-independent reaction and was worked out by Melvin Calvin and his co-workers. Without this cycle photosynthesis would be unable to occur and plants would not be able to produce the nutrients they need. The calvin cycle is a metabolic pathway which occurs within the stroma of the chloroplast. The carbon cycle works in conjunction with the products from the Light-dependent reaction to reduce CO2 into sugars and starches that the plant needs to live and grow. Without the Calvin Cycle plants would not survive due to its importance in the production of food and energy. The phases of Calvin Cycle are: * CO2 after diffusing into the stroma combines with a 5-Carbon molecule known as ribulose bisphosphate (RuBP) using an enzyme known as RuBP carboxylase/rubisco. * When CO2 and RuBP combine a 6-Carbon intermediate is formed. This 6-Carbon molecule immediately splits to form two 3-Carbon molecules known as glycerate 3-phosphate (GP) * Using ATP and NADPH2 GP is reduced to form triose phosphate (TP). The NADPH2 returns to its original form (NADP) to be reduced again in the light-dependent reaction. * The TP can either be converted into organic
Open Document