Metabolic Pathways
Define metabolism in your own words.
The chemical processes that occur within a living organism in order to maintain life. It is divided into two subtypes:
- Catabolism
- Anabolism
Energy associated with motion is...
Kinetic energy
What is thermodynamics?
The study of energy transformations.
How do spontaneous processes occur?
Spontaneous processes occur without energy input; they can happen quickly or slowly.
What is an exergonic reaction?
Catabolism: __________ products, __________ energy.
Anabolism: __________ products, __________ energy.
Catabolism: Break down products, release energy.
Anabolism: Builds/creates products, requires energy input.
The kinetic energy associated with the random movement of atoms or molecules is...
Thermal energy
Compare and contrast an isolated system and an open system. What are organisms?
An isolated system: unable to exchange energy or matter with its surroundings.
An open system: energy and matter can be transferred between the system and its surroundings. (Organism)
Compare and contrast spontaneous and nonspontaneous reactions.
For a process to occur spontaneously, it must increase the entropy of the universe.
Processes that decrease entropy are nonspontaneous; they will occur only if energy is provided.
What is an endergonic reaction?
An endergonic reaction absorbs free energy from its surroundings and is nonspontaneous.
Is cellular respiration an example of catabolism or anabolism? Explain why you believe this.
Cellular respiration is the breakdown of glucose in the presence of oxygen. Therefore, this is an example of a catabolic pathway.
Break down of products (Breaks down glucose), releases energy (converted to ATP).
Define heat.
Heat is thermal energy in transfer between objects.
What is the first law of thermodynamics? Go into detail!
Energy can be transferred and transformed, but it cannot be created or destroyed. (Energy in the universe is constant!)
AKA the principle of conservation of energy
Biological order and disorder is important. Organisms create ordered structures from...
Organisms create ordered structures from less organized forms of energy and matter.
Cells are open systems, what is a cell's relationship with equilibrium?
Cells are not in equilibrium; they are open systems experiencing a constant flow of materials.
Are steroids an example of catabolism or anabolism? Explain why you believe this.
Build or create products (increase protein within muscle cells), requires an energy input (requires ATP).
Energy that matter possesses because of its location or structure is...
Potential energy
What is the second law of thermodynamics? What is entropy?
According to the second law of thermodynamics, every energy transfer or transformation increases the entropy of the universe.
Entropy is a measure of molecular disorder or randomness.
The free-energy change of a reaction tells us whether or not the reaction occurs spontaneously. What is free energy?
A living system's free energy is energy that can do work when temperature and pressure are uniform, as in a living cell.
ATP powers cellular work by coupling exergonic to endergonic reactions. ATP is a nucleotide, what is its relationship with energy?
ATP Hydrolysis releases energy.
What does a metabolic pathway begin with? End with? How is each step catalyzed?
A metabolic pathway begins with a specific molecule and ends with a product.
Each step is catalyzed by a specific enzyme.
The potential energy that is available for release in a chemical reaction is...
Chemical energy
When energy is unusable, during every energy transfer or transformation, what happens to the energy that is unusable?
Some energy is unusable and is often lost as heat.
What is the free energy for spontaneous processes? What is the free energy for nonspontaneous processes?
𝛥G is negative for all spontaneous processes
𝛥G is zero or positive for processes that are never spontaneous
How is ATP used to perform work? Go into detail!
Cellular work (mechanical, transport, and chemical) is powered by the hydrolysis of ATP
Energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction. (Exergonic drives endergonic!!)