Electron Transport Chain Components Quiz

Electron Carriers and Ubiquinone

• Ubiquinone, also known as Coenzyme Q, acts as an electron carrier in the electron transport chain, able to accept one electron to become semiubiquinone radical or two electrons to form ubiquinol.
• Ubiquinone is a lipid-soluble molecule, enabling its free diffusion within the lipid bilayer of the mitochondrial membrane.

Functions of Prosthetic Groups

• Prosthetic groups are non-polypeptide units that assist in the functionality of proteins, including those in the electron transport chain, by facilitating electron transfer or aiding in the enzymatic activity of the protein.

Complex 1 and Electron Transfer

• Complex 1 of the electron transport chain reduces NAD+ to NADH, playing a crucial role in transferring electrons to ubiquinone, converting it into ubiquinol.

Role of Fe-S Centers

• Iron-sulfur (Fe-S) centers are pivotal in electron transfer within proteins of the electron transport chain, acting as intermediate carriers for electrons between different components of the chain.

Ubiquinone and Electron Acceptance

• When ubiquinone accepts one electron, it transforms into the semiubiquinone radical, which is a key intermediate in the electron transfer process.

Function of Complex 1

• The major functions of complex 1 include catalyzing the transfer of electrons from NADH to ubiquinone and aiding in the pumping of protons across the mitochondrial membrane, contributing to the proton gradient essential for ATP synthesis.