UNIT 2 - Energy Flashcards
define “energy” and “entropy.”
Energy is the ability to do work or cause a change
Entropy is the order, or rather disorder, of a state, more entropy, more disorder/randomness/chaos
differentiate between oxidation and reduction reactions.
OIL RIG
Oxidation is losing electrons or hydrogen atoms, reduction is gaining electrons or hydrogen atoms
describe catabolic and anabolic processes.
Catabolic = break down, Anabolic = Build rebuild
explain the basic principle of thermodynamics and calculate Gibbs Free Energy for an equation.
G=H-TS
Why are redox reactions common in biological systems?
They are common in biological systems because they allow the molecules and changes to be conserved within the system.
What is the role of enzymes in energy coupling?
The role of enzymes in energy coupling is to provide energy for the reaction by binding ATP and the other molecules involved in the reaction. Using the ATP for energy and hydrolyzing the ATP to ADP + Pi the enzyme can catalyze the reaction.
Outline the first and second laws of thermodynamics.
- The first law of thermodynamics states that energy can be exchanged between systems as heat and work.
- The second law of thermodynamics states that entropy, or disorder, increases in isolated systems.
What is entropy?
Entropy is a measurement of the molecular disorder in a system, in joules/kelvin.
What is the basis for ATP generation through substrate‑level phosphorylation?
The basis for ATP generation through substrate‑level phosphorylation is that ATP is synthesized directly through ADP and a reactive intermediate which is usually a high‑energy phosphate‑containing molecule. An example is the formation of pyruvate and ATP from phosphoenolpyruvate (PEP) and ADP.
Would the following reaction favour synthesis of ATP? Why or why not?
Phosphoenolpyruvate (PEP) + ADP ↔ Pyruvate + ATP
Yes, PEP is super PEPPY and would donate a phosphate group to ADP to make ATP and pyruvate.
What are the three forms/states of ATP synthase and what is the function of each state?
The three forms/states of ATP synthase are:
Loose (L): binds ADP + Pi
Tight (T): squeezes the ADP + Pi together to form ATP
Open (O): releases the ATP into the mitochondrial matrix.
Define photophosphorylation. What is the main difference between oxidative phosphorylation (electron transport) and photophosphorylation (photosynthesis)?
Photophosphorylation is the synthesis of ATP using light from the sun as a source of energy. The main difference between oxidative phosphorylation (electron transport) and photophosphorylation (photosynthesis) is that the electrons produced from the oxidation of biological molecules is the source of energy in oxidative phosphorylation, and light is the source of energy in photosynthesis.
How does the amount of ATP in the cell drive the processes of glycolysis and gluconeogenesis?
High amounts of ATP induce gluconeogenesis (synthesis of glucose), because there is energy available and this process requires energy. Low amounts of ATP in the cell drive the process of glycolysis (breakdown of glucose) to provide ATP to the cell.
What is a futile cycle? What do they produce? Give an example of an animal process that relies on a futile cycle.
A futile cycle is where two metabolic pathways run simultaneously in opposite directions producing no net effect except the production of heat. They produce not function except heat and ATP loss. One example of an animal process that relies on a futile cycle is: thermal homeostasis in brown tissues of young mammals (also insect flight muscles for heat, and arousal from torpor in hibernating animals).
How are muscles able to have stores of energy readily available for use? Explain the mechanism.
Muscles are able to have stores of energy ready for use by storing creatine phosphate. When muscles are resting ATP is high and this drives the synthesis of creatine phosphate and ADP. When muscles begin to contract ATP levels fall and the reaction of creatine phosphate and ADP runs in reverse to create creatine and ATP.
