Energy and Biosynthesis Flashcards
What do cells derive energy from?
The environment.
What role do activated carrier molecules play in cells?
They store and transfer energy in chemical bonds.
Why do animals need to eat?
To obtain energy.
What is the purpose of metabolism?
To convert food into energy and building blocks for cellular processes.
What happens to cells and organisms without energy?
They die.
How do chemical reactions occur?
Through the interaction of molecules.
What is the first law of thermodynamics?
Total energy in the universe is constant.
What is the second law of thermodynamics?
Free energy in the universe declines over time, leading to increased disorder (entropy).
What is free energy (G)?
Energy that can do work at constant temperature and pressure.
What does the Gibbs Free Energy equation represent?
ΔH = ΔG + TΔS.
What does a negative ΔG indicate?
A spontaneous reaction.
What is an example of a spontaneous reaction?
ATP → ADP + P releases free energy.
What allows unfavorable reactions to occur?
Coupling to favorable reactions.
What are reaction chains?
Biological reactions occurring in sequences where each step contributes to the overall metabolic goal.
What is activation energy?
The energy required to start a reaction.
How do enzymes influence activation energy?
They lower activation energy and speed up reactions.
Define oxidation in terms of electrons.
Loss of electrons.
Define reduction in terms of electrons.
Gain of electrons.
What is the most stable form of carbon?
CO₂.
What is the most stable form of hydrogen?
H₂O.
What is the glucose oxidation reaction?
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP).
What is stepwise oxidation?
Gradual electron transfer that releases energy in controlled steps.
What is hydrogenation?
Addition of hydrogen to an organic molecule (reduction).
What is the purpose of activated carrier molecules?
Store and transfer energy in chemical bonds.
What is the most abundant energy carrier?
ATP (Adenosine Triphosphate).
What does the hydrolysis of ATP release?
~ -13 kcal/mol energy.
How much ATP is recycled per day in a human?
~ 50 kg.
What do NADH and NADPH carry?
High-energy electrons from oxidation reactions.
What is the oxidized form of NAD?
NAD⁺.
What is the reduced form of NAD?
NADH.
What does acetyl-CoA transfer?
Acetyl groups in metabolism.
What is ATP hydrolysis?
ATP in water undergoes hydrolysis, releasing free energy.
What is required for ATP regeneration?
Input of energy (e.g., from food oxidation).
What do cells follow to maintain energy balance?
The laws of thermodynamics.
What determines reaction spontaneity?
Free energy (ΔG).
What role do oxidation-reduction reactions play?
They are critical for energy transfer.
How do enzymes facilitate biological reactions?
By lowering activation energy.
Fill in the blank: The oxidation of glucose can be summarized as C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + _______.
Energy (ATP).
