Chapter 7: Cellular Respiration and Fermentation Flashcards
What are the three key pathways to cellular respiration?
Glycolysis, The citric acid cycle (Krebs cycle), and oxidative phosphorylation at the ETC
What are catabolic pathways
pathways that break down organic molecules, releasing stored energy
How do organic molecules possess potential energy?
As a result of the arrangment of electrons in the bonds betweeen their atoms
What is fermentation
The partial breakdown of sugars without O2 (anaerobic)
What is aerobic respiration?
The most efficient catabolic pathway. This occurs in the presence of O2 which makes this an aerobic process.
What is the chemical equation for cellular respiration?
C6H12O6 + 6O2 –> 6 CO2 + 6H20 + NRG
Is cellular resperiation exergonic or endergonic?
exergonic
How is ATP synthesized in cellular respiration (summarized)
When cells break down glucose, the realocation of electron releases energy stored in organic molecules, and this energy is used to synthesize ATP
What is oxidation?
the loss of electrons
What is reduction?
the addition of electrons
What is the reducing agent?
the electron donor
What is the oxidizing agent?
the electron acceptor
How do electrons move throughout compounds?
AN electron loses potential energy when it shifts from a less electronegative atom toward a more electronegative atom
Is glucose oxidized or reduced?
oxidized
Is O2 oxidized or reduced?
reduced
Why are organic molecules with many hydrogen atoms great sources for energy?
These type of molecules are high in energy (hydrocarbons) because they are a soruce of “hilltop” (high energy) electrong with the potential to fall closer to O2
If electrons and H+ ions were transferred directly to oxygen what would occur?
This reaction would result in an uncontrolled release of energy. This release of energy would cause the cells of living organisms to immediately die.
Which coenzyme functions as an oxidizing agent?
NAD+
Is NAD+ reduced or oxidized and how?
NAD+ is reduced and becomes NADH with the addition 2 electrons (2e-) and 1 Proton (H+)
What is the function of dehydrogenases?
they remove a pair of hydrogen atoms (2 electrons and 2 protons) from the substrate, thereby oxidizing it.
How many electrons and protons does NAD+ deliver to the ETC?
NAD+
Which oxidizing agent delivers more energy: NAD+ or FAD
NAD+
