Lecture 3 Flashcards
What is the general energy flow through life and through an individual organism?
Energy is captured and stored into reduced bonds, transferred to ATP following oxidation, and used to perform biological work.
What are anabolic and catabolic pathways?
Anabolic pathways build complex molecules from simpler ones, requiring energy, while catabolic pathways break down complex molecules into simpler ones, releasing energy.
What are the major fuel stores in the body?
The major fuel stores are glycogen and fat.
What are the important sources of fuel in the diet that contribute to ATP synthesis?
Carbohydrates, fats, and proteins.
What are the principles of bioenergetics?
Bioenergetics involves the study of energy flow and transformation within biological systems, governed by the laws of thermodynamics.
What are the components of ΔG°’?
ΔG°’ (standard Gibbs free energy change) is calculated using the change in enthalpy (ΔH°’), change in entropy (ΔS°’), and temperature (T).
Why does ATP have a highly negative ΔG°’?
The highly negative ΔG°’ of ATP hydrolysis is due to the release of free energy when the phosphoanhydride bonds are broken, driving chemical work.
What is the ATP-ADP cycle?
The cycle involves ATP being hydrolysed to ADP and inorganic phosphate, releasing energy, and ADP being rephosphorylated to ATP using energy from metabolism.
Why is the negative ΔG°’ value for ATP hydrolysis important?
It indicates that ATP hydrolysis releases a significant amount of free energy that can be used to perform biological work.
How is the free energy from ATP hydrolysis used to carry out biological work?
The free energy released drives endergonic reactions and processes like muscle contraction and ion transport.
How does energy capture and transfer occur in cells?
Energy is captured in reduced bonds (C=O, C-C, and C-H) and transferred to ATP through oxidation.
What is the significance of the phosphate bond in ATP?
The phosphate bond of ATP stores energy and acts as a short-term energy source for cellular processes.
How do thermodynamic laws govern life?
Life processes are governed by the conservation of energy (1st law) and the increase of entropy (2nd law).
What is Gibbs free energy (ΔG)?
Gibbs free energy is the amount of energy available to do work in a system, predicting whether a reaction occurs spontaneously.
What are the stages of catabolism?
1) Hydrolysis of complex molecules to building blocks, 2) Conversion of building blocks to Acetyl CoA, 3) Oxidation of Acetyl CoA in the citric acid cycle.
