Energy Flow in Marine Ecosystem kau

Energy Flow In Marine Ecosystem Kau-Free PDF

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Introduction, Marin ecosystem is a functional system and consists of living groups and the surrounding. environment,It is composed of some groups and subgroups. 1 The physical environment seawater and dissolved salts and suspended particles. 2 Bottom sediments,3 Living organisms,3 Microorganisms saprobe. According to their way of living and their environment living groups are classified as. Intertidal littoral,Sublittoral up to 200 m depth,Pelagic open water. Constituents of the marine ecosystem are also classified according to their function. Abiotic substances all chemicals present in solution or in bottom sediments. Producers autotrophs photosynthetic organisms marine plants. Consumers heterotrophs organisms feeding on marine plants and prefabricated organic. Decomposers reduces organisms feeding on dead organisms and recycle the organic matter. These components are linked together in a closed cycle Fig 1. Environment and abiotic,Reducers decomposrs Producers autotrophs.
Consumers heterotrophs,From Fig 1 we can deduce the following points. 1 In some ecosystems the cycle could be completed with only three components odd system. 2 It is clear that the composition of the environment controls the biological activity of all the living. organisms However living organisms greatly determine concentrations and distribution the. abiotic material Living organisms influence and determine the distribution of nutrients. precipitation of carbonates reduction of sulphate ions distribution of dissolved oxygen and. carbon dioxide in water and the atmosphere, 3 The presence of forces and counter forces that act against any significant compositional. variability and keep the chemical composition almost constant However human interference. may force these changes,4 Activity of the living organisms depends on. 1 Recycling of the abiotic material,2 Flow of energy inside the system. Energy Flow in The Marine Ecosystem,What is energy.
Energy is the capacity of a physical system to perform work Energy exists in several forms. such as heat kinetic or mechanical energy light potential energy electrical or other. Energy is either, Stored or potential chemical potential energy gravitational potential energy. Energy in transition heat work, Heat transitional energy which transfers between bodies or among particles in the same. Heat passes from the hot body source to the cold body sink. Heat transfer by,Conduction,Convection, Work mechanical work is the amount of energy transferred by a force acting. through a distance, In thermodynamics work is the quantity of energy transferred from one system to. another without an accompanying transfer of entropy. Thermodynamics is the study of the conversion of heat energy into different forms. of energy in particular mechanical chemical and electrical energy different. energy conversions into heat energy,What is a thermodynamic system.
a thermodynamic system originally called a working substance is defined as that part of. the universe that is under consideration A real or imaginary boundary separates the. system from the rest of the universe which is referred to as the environment or. surroundings, a phase is a region of space a thermodynamic system throughout which all physical. properties of a material are essentially uniform Examples of physical properties include. density index of refraction and chemical composition A simple description is that a. phase is a region of material that is chemically uniform physically distinct and often. mechanically separable In a system consisting of ice and water in a glass jar the ice. cubes are one phase the water is a second phase and the humid air over the water is a. third phase The glass of the jar is another separate phase. First law of thermodynamics, Energy can be transformed changed from one form to another but it can. neither be created nor destroyed,E2 E1 E q w 1, q is positive when the system absorbs heat endothermic reactions. q is negative when the system radiates heat exothermic reactions. w is positive when work is done by the system,W is negative when work is done on the system. Palmitic acid,Chemical reactions may take place either.
1 Under constant pressure reactions in the ocean,2 Under constant volume in closed system. In the first case if the volume changes work is done and equals P V where P is the. constant pressure atmospheric pressure and V is the change in volume. Change in internal energy,E q w q P V 2, Since most of the reactions takes place under constant pressure. qp E P V H 3,H is called enthalpy change or heat of reaction. Under constant volume V equals zero and P V will be zero therefore. E and H depend only on the initial and the final state of the reactants and not by any. mean on the intermediate steps between the two states. 1 Indication of spontaneous reactions,Exothermic reactions H ve are spontaneous. while endothermic H ve reactions are not,2 Measure of stability.
When the H of the products of the dissociation of a substance is negative the reaction is most. probably spontaneous, This means that the substance is unstable with respect to the specific products and under the specific. conditions of the reaction, For example it is not exact if we say that hydrogen peroxide H2O2 is unstable without pr cising the. products of the dissociation and the conditions of the reaction. At 25 o C and one atm H2O2 is stable and does not dissociate easily to its constituents. H2O2 l H2 g O2 g H 44 8 kcal, However it is unstable when it dissociates according to the reaction. H2O2 l H2O l 1 2 O2 g H 23 4 kcal, 3 H is used for the determination of other thermodynamic properties such as G. Determination of H,1 The experimental method, It is possible to measure the heat absorbed or radiated during any chemical reaction.
using a microcalorimeter,Since in a closed system we measure qv. To obtain H the value of qv should be corrected for the work done by the system. Suppose the reaction,CH4 g 2O2 CO2 g 2H2O l qv 211 kcal. The value of qv could be corrected by adding the value of P V at 25o C and one. P V 1 atm X 2 x 24 5 49 l atm,1 l atm 24 2 cal,P V 49 x 24 2 1 2 kcl. H 211 1 2 212 2 kcal,By calculation, This method is based on the Hess s which indicates that H and E depend on the state of. reactants and products of the reaction and not on steps of the reaction In multistep. reactions the final H is the sum of the H H of the individual steps. Consider the oxidation of methane to carbon monoxide. CH4 g 1 5O2 CO g 2H2O l, This reaction could be regarded as two step reaction.
1 CH4 g 2O2 CO2 g 2H2O l H 212 kcal 1,2 CO2 g CO 0 5 O2 H 68 3 kcal 2. 3 Adding equation 1 to equation 2 we get,H 212 68 3 144 7 kcal 3. The free energy of the system, It is the part of the total energy that determines the ability of any substance to exchange. energy chemical reaction, the term thermodynamic free energy refers to the amount of work that can be extracted. from a system, It is a subtraction of the entropy of a system multiplied by a reference temperature.
giving the unusable energy from the total energy yielding a thermodynamic state. function which represents the useful energy,Total energy free energy organization energy. T absolute temperature OK, Changes in free energy of any reaction is a measure of how possible it can take place. Spontaneous reactions are those that high and negative G and H and positive T S values. Energy Flow in Marine Ecosystem Introduction Marin ecosystem is a functional system and consists of living groups and the surrounding environment It is composed of some groups and subgroups 1 The physical environment seawater and dissolved salts and suspended particles 2 Bottom sediments 3 Living organisms 1 Animals 2 Plants 3 Microorganisms saprobe According to their way of living

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