Energy Basics
What are the two main forms of energy
Kinetic energy (energy of motion) and Potential energy (stored energy)
A reaction with a negative ΔG is called what type of reaction?
Exergonic (spontaneous, energy-releasing).
Oxidation means the ___ of electrons, while reduction means the ___ of electrons.
Loss; gain
How many main stages make up cellular respiration?
Four: Glycolysis, Pyruvate Processing, Citric Acid Cycle, and Electron Transport & Oxidative Phosphorylation.
How many net ATP are produced per molecule of glucose during glycolysis?
2 ATP (net gain)
What type of energy is stored in the bonds of molecules like glucose or ATP?
Potential energy (specifically, chemical potential energy)
A reaction that requires energy input (positive ΔG) is called what?
Endergonic
When a molecule loses hydrogen atoms during a reaction, what usually happens to its electrons?
It loses electrons and is therefore oxidized.
In which organelle does most of cellular respiration occur in eukaryotic cells?
Mitochondria
What is the final product of glycolysis?
Two molecules of pyruvate (3C each).
According to the first law of thermodynamics, energy cannot be ___ or ___, only transformed.
Created or destroyed
What molecule is used by cells to couple exergonic and endergonic reactions?
ATP
In cellular respiration, glucose is ___ and oxygen is ___.
Glucose is oxidized; oxygen is reduced.
Which stage of respiration does not require oxygen and occurs in the cytosol?
Glycolysis
Glycolysis has two phases — what are they?
Energy investment phase and energy payoff phase
What happens to entropy in all natural processes, according to the second law of thermodynamics?
Entropy (disorder) always increases.
The hydrolysis of ATP to ADP and Pi is an example of what type of reaction?
Exergonic reaction
What molecules act as electron carriers during redox reactions?
NAD⁺/NADH, FAD/FADH₂, and NADP⁺/NADPH.
Which type of reaction is cellular respiration overall — endergonic or exergonic?
Exergonic.
Which enzyme is the key regulatory enzyme in glycolysis that is inhibited by ATP?
Phosphofructokinase. (PFK)
What term describes the total sum of all chemical reactions in a cell?
Metabolism
The regeneration of ATP from ADP and Pi is an example of what type of reaction?
Endergonic reaction
When FAD becomes FADH₂, is it oxidized or reduced?
Reduced (it gains electrons and hydrogen).
What is the overall chemical equation for cellular respiration?
C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + energy (ATP + heat).
What type of inhibition occurs when ATP binds to the regulatory site of phosphofructokinase to slow the pathway?
Feedback inhibition (allosteric inhibition).