A reduced molecule ______.
a. has gained electrons
b. has become more positive in charge
c. has lost electrons
d. is an electron donor

Verified step by step guidance

1. Understand the concept of reduction in chemistry, which involves the gain of electrons by a molecule, atom, or ion.
2. Recall that when a molecule gains electrons, it becomes more negatively charged, as electrons carry a negative charge.
3. Consider the options provided: (a) has gained electrons, (b) has become more positive in charge, (c) has lost electrons, (d) is an electron donor.
4. Eliminate options that do not align with the definition of reduction. For example, losing electrons or becoming more positive in charge would not be consistent with reduction.
5. Identify the option that correctly describes a reduced molecule based on the understanding that reduction involves gaining electrons.

Key Concepts

Reduction in Biochemistry

Reduction refers to the gain of electrons by a molecule, which often results in a decrease in its oxidation state. This process is fundamental in redox reactions, where reduction and oxidation occur simultaneously. In biological systems, reduced molecules often serve as energy carriers, such as NADH and FADH2.

Oxidation-Reduction Reactions

Oxidation-reduction (redox) reactions are chemical processes where the oxidation state of molecules changes due to the transfer of electrons. Oxidation involves the loss of electrons, while reduction involves the gain of electrons. Understanding these reactions is crucial for grasping metabolic pathways and energy production in cells.

Electron Donors and Acceptors

In redox reactions, electron donors are molecules that lose electrons and become oxidized, while electron acceptors gain electrons and become reduced. This transfer is essential for various biochemical processes, including cellular respiration and photosynthesis, where energy is harnessed from electron flow.