So how can these factors have an effect on the rate of photosynthesis? Lets start off with the light intensity. When the light intensity is poor, there is a shortage of ATP and NADPH, as these are products from the light dependent reactions. Without these products the light independent reactions can't occur as glycerate 3-phosphate cannot be reduced. Therefore a shortage of these products will limit the rate of photosynthesis. When the carbon dioxide concentration is low, the amount of glycerate 3-phosphate produced is limited as carbon dioxide is needed for its production and therefore the rate of photosynthesis is affected. Finally, many enzymes are involved during the process of photosynthesis. At low temperatures these enzymes work slower. At high temperatures the enzymes no longer work effectively. This affects the rate of the reactions in the Calvin cycle and therefore the rate of photosynthesis will be affected.
The light-independant reactions of photosynthesis occur in the stroma of the chloroplast and involve the conversion of carbon dioxide and other compounds into glucose. The light-independent reactions can be split into three stages, these are carbon fixation, the reduction reactions and finally the regeneration of ribulose bisphosphate. Collectively these stages are known as the Calvin Cycle.
Variables: The variables that might affect the rate of photosynthesis in this experiment are: Temperature: When the temperature rises so does the rate of photosynthesis; this is because as the temperature around the plant rises the enzymes controlling photosynthesis inside the chloroplasts heat up and start moving around faster, the fast moving molecules collide with other fast moving enzymes causing them to react....
Photophosphorylation is the production of ATP using the energy of sunlight. Photophosphorylation is made possible as a result of chemiosmosis. Chemiosmosis is the movement of ions across a selectively permeable membrane, down their concentration gradient. During photosynthesis, light is absorbed by chlorophyll molecules. Electrons within these molecules are then raised to a higher energy state. These electrons then travel through Photosystem II, a chain of electron carriers and Photosystem I. As the electrons travel through the chain of electron carriers, they release energy. This energy is used to pump hydrogen ions across the thylakoid membrane and into the space within the thylakoid. A concentration gradient of hydrogen ions forms within this space. These then move back across the thylakoid membrane, down their concentration gradient through ATP synthase. ATP synthase uses the energy released from the movement of hydrogen ions down their concentration gradient to synthesise ATP from ADP and inorganic phosphate.
The first step in photosynthesis is the interaction of light with chlorophyll molecules. The chemical structures of the various chlorophyll molecules are based upon the cyclic tetrapyrrole that is also seen in the heme group of globins and cytochromes. Various modifications of this group, namely ring saturation characteristics and substitutions on the rings provide a series of pigment molecules that, as a group, absorb effectively over the wavelength range of 400 nm - 700 nm, the spectrum of . It is the high degree of conjugation of these molecules that makes them so efficient as absorbers of visible light.
Photosynthesis occurs inside chloroplasts. Chloroplasts contain chlorophyll, a green pigment found inside the thylakoid membranes. These chlorophyll molecules are arranged in groups called photosystems. There are two types of photosystems, Photosystem II and Photosystem I. When a chlorophyll molecule absorbs light, the energy from this light raises an electron within the chlorophyll molecule to a higher energy state. The chlorophyll molecule is then said to be photoactivated. Excited electron anywhere within the photosystem are then passed on from one chlorophyll molecule to the next until they reach a special chlorophyll molecule at the reaction centre of the photosystem. This special chlorophyll molecule then passes on the excited electron to a chain of electron carriers.
You have already studied the "dark reaction" and I will refer you to Dr. Diwan's notes on the subject. As the overall process of photosynthesis involves a series of electron transfer reactions, we are in the realm of oxidation-reduction chemistry, and it would help to review the basics of these processes because we will be going into this topic in greater depth. There is a direct analogy to electron transfer in the mitochondrion, in which clumps of energy are transferred from one electron carrier to another along a "chain" and H+ ions are translocated out, across the mitochondrial membrane, thus generating an electrochemical gradient. The energy inherent in this gradient is used to synthesize ATP in the process of "oxidative phosphorylation." The same processes occur in photosynthesis and the chloroplast, the site of photosynthesis in plants and blue-green algae (but not in photosynthetic bacteria), is the analog of the mitochondrion in eukaryotes.
The existence of atoms, now supported by evidence from modern instruments, was first postulated as a model that could explain both qualitative and quantitative observations about matter (e.g., Brownian motion, ratios of reactants and products in chemical reactions). Matter can be understood in terms of the types of atoms present and the interactions both between and within them. The states (i.e., solid, liquid, gas, or plasma), properties (e.g., hardness, conductivity), and reactions (both physical and chemical) of matter can be described and predicted based on the types, interactions, and motions of the atoms within it. Chemical reactions, which underlie so many observed phenomena in living and nonliving systems alike, conserve the number of atoms of each type but change their arrangement into molecules. Nuclear reactions involve changes in the types of atomic nuclei present and are key to the energy release from the sun and the balance of isotopes in matter.
Leukemia is a type of cancer of the blood or bonemarrow characterized by an abnormal increase in immature leukocytescalled ‘blasts’ which are arrested in the early phases ofdifferentiation. Most leukemias show non-random chromosomalabnormalities, of which the majority are chromosomaltranslocations. These genetic lesions cause activation ofproto-oncogenes and inactivation of tumor-suppressor genes,ultimately resulting in leukemogenesis. The molecular pathologicalalterations in the disease impair the regulation of normal cellularprocesses, such as cell differentiation, cell proliferation, cellcycle progression and cell death. Leukemia is a common malignantdisease and can occur in individuals at any age. Thousands ofpeople died from leukemia every year around the world. There arefour major types of leukemia, including acute myeloid leukemia(AML), chronic myeloid leukemia (CML), acute lymphoblastic leukemia(ALL) and chronic lymphocytic leukemia (CLL). Acute leukemia ischaracterized by a rapid clinical progression and accumulation ofmalignant blood cells, whereas chronic leukemia is characterized bya slow clinical progression and an increase in relatively maturebut abnormal leukocytes. Lymphoblastic and lymphocytic leukemiasinvolve lymphocytes. Myeloid leukemia affects red blood cells, someleukocytes and platelets. Epidemiologic, genotypic and animal modeldata all indicate a multistep and complicated oncogenic process ofleukemia. Notably, the diversifying genetic and molecularalterations that drive malignant transformation of blood cellscritically contribute to the pathogenesis of leukemia and theheterogeneity of the disease. Therefore, understanding the geneticbasis and molecular events of various leukemias may provide newinsights into leukemia diagnoses, prognoses and therapies.
The carbon atom light dependent reactions light independent reactions Transitioning between photosynthesis and respiration Twelve three-carbon molecules are formed from every six carbon dioxide molecule.
The majority of differentially expressed proteins indenervated TA muscle identified in our study are enzymes involvedin the regulation of energy metabolism, including α- and β-enolase,glycogen phosphorylase muscle form (PYGM), creatine kinase M-type(KCRM) and GAPDH (G3P). Cross-referencing with KEGG pathway dataindicated that these energy metabolism-related enzymes are involvedin the glycolytic, Krebs cycle and oxidative phosphorylationpathways. These observations suggest that time-dependent changes inenergy production might be a dominant molecular event occurring indenervated skeletal muscle. The altered expression of energymetabolism-related proteins can lead to an overall disturbance ofthe muscle, and ultimately contribute to the establishment ofpathological states, such as atrophy (–).