Energy, ATP and Life Flashcards
What are the different forms of energy and give an example of energy transformation
Energy can exist in chemical, electrical, mechanical, and electromagnetic radiation forms. An example of energy transformation is the chemical energy in a flashlight battery converting to electrical energy, which then becomes light and heat.
What is kinetic energy and give some examples?
Kinetic energy is energy due to motion. Examples include ocean waves, a falling rock, a kicked football, the flow of electrons (electricity), and light (photons).
What is potential energy and how is it influenced in atoms?
Potential energy is stored energy due to an object’s position or structure. For example, a boulder on a cliff has potential energy because of its position in Earth’s gravitational field. In atoms, potential energy is influenced by electronegativity; atoms like oxygen and nitrogen hold electrons tightly, resulting in less potential energy compared to atoms like carbon and hydrogen.
What is thermodynamics and what does it study
Thermodynamics is the study of energy and its transformations. It examines how systems exchange energy with their surroundings
What are the three types of systems in thermodynamics?
Isolated System: No exchange of energy or matter with surroundings (e.g., the universe).
Closed System: Exchanges energy but not matter with surroundings (e.g., a saucepan with a lid, Earth).
Open System: Exchanges both energy and matter with surroundings (e.g., oceans)
What does the First Law of Thermodynamics state?
The First Law of Thermodynamics states that energy can be transformed or transferred but cannot be created or destroyed. For example, at Niagara Falls, the potential energy of water converts to kinetic energy as it falls, then to other forms like heat and mechanical energy.
What does the Second Law of Thermodynamics state?
The Second Law of Thermodynamics states that energy tends to spread out or disperse, known as entropy. For example, when a heated pan cools, the heat spreads throughout the kitchen until evenly distributed. Machines can’t be 100% efficient because some energy is always lost to the surroundings as heat.
What is a spontaneous reaction in thermodynamics?
A spontaneous reaction is a process that can occur without an input of energy. It refers to the likelihood of a reaction to proceed by itself, not how fast it occurs.
What is enthalpy and how does it relate to endothermic and exothermic reactions
Enthalpy is the total potential energy of a system. Endothermic reactions absorb energy and have products with more potential energy (positive ΔH). Exothermic reactions release energy and have products with less potential energy (negative ΔH).
How does entropy influence the spontaneity of a reaction?
Entropy measures the dispersal of energy. Reactions tend to be spontaneous if the products have greater entropy than the reactants, meaning energy is more spread out.
What is Gibbs free energy and how is it calculated?
Gibbs free energy (ΔG) is a measure of whether a process is spontaneous. It is calculated using the formula ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.
How do ΔG values determine if a reaction is spontaneous or nonspontaneous?
A reaction is spontaneous if ΔG is negative (exergonic process) and nonspontaneous if ΔG is positive (endergonic process).
Why does ice melt spontaneously at room temperature?
Ice melts spontaneously at room temperature because, although the melting is endothermic (ΔH is positive), the large increase in entropy (TΔS is positive) makes ΔG negative, driving the process spontaneously
Why is diffusion considered a spontaneous process?
Diffusion is spontaneous because it results in an increase in entropy as molecules move from an area of higher concentration to lower concentration, spreading out the energy.
What is chemical equilibrium in the context of exergonic processes?
Chemical equilibrium occurs when the rate of the forward reaction equals the rate of the backward reaction, and the system’s free energy is at its lowest point (ΔG = 0). The proportion of reactants to products remains constant at equilibrium.
What is a key characteristic common to all life forms regarding energy?
One key characteristic common to all life forms is the ability to harness and utilize energy, which is crucial for maintaining high levels of organization.
How do living systems seem to contradict the second law of thermodynamics and how is this resolved?
Living systems seem to contradict the second law of thermodynamics, which states that the entropy of a system and its surroundings must always increase. This is resolved by recognizing that organisms are open systems that continuously import energy and matter from their environment, maintaining a low-entropy state internally while increasing the entropy of their surroundings.
Why must living systems constantly consume energy?
Living systems must constantly consume energy because cellular components are prone to damage and breakdown, requiring ongoing synthesis of proteins, carbohydrates, and other molecules to repair and replace damaged parts. This constant energy supply is necessary to maintain life and prevent cells from reaching chemical equilibrium (ΔG = 0).
