Thermodynamics And Atp: Breaking Down Energy's Rules

The second law of thermodynamics states that the entropy of a closed system will always increase over time. Entropy is a measure of the disorder of a system. The second law implies that heat will not spontaneously pass from a colder body to a warmer body.

The first law of thermodynamics states that energy can be converted from one form to another but cannot be created or destroyed.

The breakdown of glucose is an example of a spontaneous natural process, and therefore the second law of thermodynamics applies to it. The breakdown of glucose can be described by the equation:

ΔG = ΔH - TΔS ≤ 0

Where ΔG is the change in Gibbs free energy, ΔH is the change in enthalpy, T is the temperature, and ΔS is the change in entropy.

The breakdown of glucose can be described as a conversion of 40% of potential energy to ATP and 60% to thermal and unusable energy. This process is possible because the breakdown of glucose does not decrease the total entropy of the reaction and its environment.

The second law of thermodynamics is a physical law based on universal empirical observation

The second law of thermodynamics is concerned with heat and energy interconversions. It states that heat always flows spontaneously from hotter to colder regions of matter. This is often described as heat flowing "downhill" in terms of the temperature gradient. The law also asserts that not all heat can be converted into work in a cyclic process.

The second law establishes the concept of entropy as a physical property of a thermodynamic system. Entropy is a measure of the degree of disorder in a system. The law predicts whether processes are forbidden, despite obeying the requirement of conservation of energy as expressed in the first law of thermodynamics. For example, while the first law allows for a cup that has fallen off a table and broken on the floor to reverse this process and have its fragments come back together and "jump" back onto the table, the second law allows the former process but denies the latter.

The second law of thermodynamics is particularly relevant in the context of energy pyramids, where it states that usable energy always decreases. In an energy pyramid, 90% of usable energy is lost in each level. When a first-level consumer eats a plant, not all of the energy stored in the plant is converted to ATP in the herbivore due to entropy. The organism must then use energy to maintain its life functions, and this energy is "lost" as heat and is no longer usable by the organism or any other organism. When the first-level consumer is eaten by a second-level consumer, only 10% of the energy that was contained in the plant remains to be used by the predator.

While the second law of thermodynamics may seem paradoxical, as nature is filled with examples of order emerging from chaos, it is important to note that this law only applies when the system under study is in a quiescent state called equilibrium. In this state, the system's parameters, such as mass, energy, and shape, have ceased to change. When two objects at different temperatures are put together, heat flows from the hotter object to the colder one until they reach the same temperature, or thermal equilibrium. From that point on, nothing changes.

The second law of thermodynamics also has implications for living organisms. It dictates that entropy always seeks to increase over time, which means that everything eventually breaks down into more random and chaotic collections of smaller components. This is where the concept of "breaking" the second law comes into play. Theoretically, if the second law could be broken, it would be possible to have perpetually running machines, infinitely recycling energy, and electronics that repair themselves. However, the second law is a fundamental rule of physics and has been widely accepted based on universal empirical observation.

The law establishes the concept of entropy as a physical property of a thermodynamic system

The second law of thermodynamics establishes the concept of entropy as a physical property of a thermodynamic system. It is a physical law based on universal empirical observation concerning heat and energy interconversions.

The law asserts that the entropy, or disorder, of an isolated system will always increase or remain constant over time. It predicts whether processes are forbidden despite obeying the requirement of conservation of energy as expressed in the first law of thermodynamics and provides necessary criteria for spontaneous processes. For example, the first law allows the process of a cup falling off a table and breaking on the floor, but the second law denies the reverse process of the cup fragments coming back together and jumping back onto the table.

The second law may be formulated by the observation that the entropy of isolated systems left to spontaneous evolution cannot decrease, as they always tend toward a state of thermodynamic equilibrium where the entropy is highest at the given internal energy. An increase in the combined entropy of a system and its surroundings accounts for the irreversibility of natural processes, often referred to in the concept of the arrow of time.

The law also allows for the definition of the concept of thermodynamic temperature, although this has been formally delegated to the zeroth law of thermodynamics. The second law is concerned with the direction of natural processes, asserting that a natural process runs only in one sense and is not reversible.

The second law of thermodynamics is a cornerstone in the world of physics, setting constraints on what is physically possible. It governs the unstoppable march of time and the flow of energy.

The law predicts the irreversibility of natural processes

The second law of thermodynamics is a physical law based on the universal empirical observation of heat and energy interconversions. It establishes the concept of entropy as a physical property of a thermodynamic system. The law predicts whether processes are forbidden, despite obeying the requirement of conservation of energy as expressed in the first law of thermodynamics.

The second law asserts that a natural process runs only in one direction and is not reversible. This irreversibility of natural processes is a result of the increase in the combined entropy of a system and its surroundings. In other words, the entropy of isolated systems left to spontaneous evolution cannot decrease, as they tend towards a state of thermodynamic equilibrium with the highest entropy at a given internal energy. This is often referred to as the "arrow of time".

For example, consider a cup falling off a table and breaking. While the first law of thermodynamics allows for both the process of the cup breaking and the reverse process of the fragments coming back together, the second law only allows the former and denies the latter. The second law also predicts that heat will always flow spontaneously from hotter to colder regions of matter, and that not all heat can be converted into work in a cyclic process.

The irreversibility of natural processes, as predicted by the second law, has profound implications. It suggests that the universe is becoming increasingly disordered, and this degeneration cannot be reversed. While nature may seem to defy this law with examples of order emerging from chaos, the second law remains universal and applicable to a wide range of systems, from steam engines to molecular motors.

The law applies to both closed and open systems

The second law of thermodynamics is a physical law based on universal empirical observation concerning heat and energy interconversions. It establishes the concept of entropy as a physical property of a thermodynamic system.

In a closed system, the second law of thermodynamics states that the entropy of the system will always increase or remain constant over time. This means that the system will tend towards a state of greater disorder or randomness. In an open system, the law still applies, but there is an additional factor to consider: the exchange of matter and energy with the surroundings.

For example, consider a cup of hot coffee in a room. The coffee will gradually cool down as heat flows from the coffee to the surrounding air until it reaches thermal equilibrium with the room. This is an example of an open system, as the coffee is losing heat energy to its surroundings. The second law of thermodynamics tells us that the heat will not spontaneously flow back into the coffee to raise its temperature above that of the room.

The concept of entropy also applies to living organisms, which can be considered open systems. Organisms require a constant input of energy in the form of food or light to sustain their highly ordered and complex structures. Without this input of energy, the second law of thermodynamics dictates that the organism will break down into smaller, more disordered components.

In summary, the second law of thermodynamics applies to both closed and open systems, describing the tendency of systems to increase in entropy or disorder over time. In open systems, the exchange of matter and energy with the surroundings can either increase or decrease the entropy of the system, but the overall entropy of the universe always increases or remains constant.

The law governs the flow of energy

The second law of thermodynamics governs the flow of energy by stipulating that the entropy, or disorder, of an isolated system will always increase or remain constant over time. In other words, the law dictates that entropy always seeks to increase over time, with the theoretical final or equilibrium state being one in which entropy is maximised and there is no order in the universe or closed system. This means that spontaneous processes, those that occur without external influence, are always processes that convert order to disorder.

The second law is a statistical law, applying generally to macroscopic systems. However, it does not preclude small-scale variations in the direction of entropy over time. The Fluctuation theorem, for example, states that as the length of time or the system size increases, the probability of a negative change in entropy (i.e. going against the Second Law) decreases exponentially. So, on very small time scales, there is a real probability that fluctuations of entropy against the Second Law can exist.

The second law also allows for the imposition of order upon a system. Examining the standard mathematical form of the Second Law:

ΔSsystem + ΔSsurroundings = ΔSuniverse,

Where ΔSuniverse > 0

Shows that entropy can decrease within a system as long as there is an increase of equal or greater magnitude in the entropy of the surroundings of the system.

The second law is a cornerstone in the world of physics, setting constraints on what is physically possible. However, the world of quantum mechanics and thought experiments like Maxwell's demon pose fascinating challenges to our understanding of this seemingly invincible law.

Frequently asked questions