Bio Comprehensive Essay Example | Topics and Well Written Essays - 750 words

Bio Comprehensive - Essay Example Its inner layer invaginates and form thylakoid disks that are arranged in stacks called "grana" where chlorophyll is concentrated and so with other pigment absorbing organs. The membranes are very much important in the process of photosynthesis of plants because it is where the organelles responsible for absorbing light (chlorophyll in chloroplast) are suspended or being housed One way to measure the efficiency of chloroplast when it is intact is through Fluorescence. This will be able to measure the chlorophyll in the flourimeter. The spectrum of fluorescence is different to that of absorbed light, with the peak of fluorescence emission being of longer wavelength than that of absorption. Therefore, fluorescence yield can be measured by exposing a leaf to light of defined wavelength and measuring the amount of light re-emitted at longer wavelengths. When transferring photosynthetic material from the dark into the light, an increase in the yield of chlorophyll fluorescence happens over a time period of around 1 s. This increase has then been explained as a consequence of reduction of electron acceptors in the photosynthetic pathway, downstream of PSII, notably plastoquinone and in particular, QA. Once PSII absorbs light and QA has accepted an electron, it is not able to accept another until it has passed the first onto a succeeding electron carrier (QB). Du ring this period, the reaction centre is said to be 'closed'. At any point in time, the occurrence of a fraction of closed reaction centers leads to an overall reduction in the efficiency of photochemistry and so to a matching increase in the yield of fluorescence. Our body part is made up of cells. These cells multiply in a process called cell division. If the division of the cells is having irregularities in number tumors develops. There will be too numerous divisions of cells. But what triggers human malignant cancers is due to mutations of both signal transduction pathways and in the mechanisms that control the cell cycle. Signal transduction responses are responsible for gene activation, manufacturing of metabolic energy, and cell movement. It has something to do with the cell activity. It has even something to do with the modification of the cell skeleton. Since it is responsible for gene activation it leads to gene expression as proteins. Gene activation leads to further effects, since genes are expressed as proteins, many of which are enzymes, transcription factors or other regulators of metabolic activity. Because transcription factors can activate still many genes in turn, an initial stimulus can trigger via signal transduction the expression of whole suite of genes and a panoply of physiolgical events. When there is a mutation of the pathway the expresion of genes also mutates. This mutation may lead to cancers. There sequence is sometimes affected by the mutation. In every expresion like GUC for example when mutated may lead to GUA and this does not mean the same as what GUC codes for. To determine a patient with cancer caused by mutation of the tranduction signal pathway, you can conduct mutation analysis. With this, you can be able to trace if the patient's cancer is cause mainly of his/her signal transduction being mutated. Enzymes are catalysts. Mostly of these are protein based. Enzymes attach temporarily to one or more of the reactants of the reaction they catalyze. In doing so, they decrease the amount of activation