Chapter 9.1.2 (Exam 2) Redox Reactions Flashcards
Cells Harvest Chemical Energy from Glucose Oxidation
What are oxidation-reduction (redox) reactions?
One substance transfers electrons to another substance
Oxidation and reduction always occur together
What is reduction in redox reactions?
Gain of electrons/hydrogen and loss of oxygen
What is oxidation in redox reactions?
Loss of electrons/hydrogen and gain of oxygen
Do redox reactions involve a complete transfer of electrons?
Not all redox reactions involve a complete transfer of electrons—it may be incomplete
Electrons aren’t lost or gained, but an atom’s share of electrons is changed due to polar bonds
How are electrons shared in glucose and CO2?
In glucose, the C—C bonds are shared equally
In CO2, the C=O bonds are polar
Which element gets reduced in a polar covalent bond? Which element gets oxidized?
In a polar covalent bond, more electronegative element gets reduced and the less electronegative element gets oxidized
What is the reducing agent and oxidizing agent in glucose metabolism?
In glucose metabolism, glucose is the reducing agent and O2 is the oxidizing agent
If a molecule is more reduced does it have more or less energy? If it is more oxidized?
A more reduced molecule has more electrons, and more energy
A more oxidized molecule has less electrons, and less energy
What is the function of Coenzyme NAD+ in redox reactions?
It is a key electron carrier
It can be reduced to form NADH
What is the final electron acceptor in aerobic respiration?
O2
How many metabolic pathways operate in aerobic conditions?
Four metabolic pathways
What happens to pyruvate in anaerobic conditions?
It is metabolized by fermentation
