Question

The electrons from Photosystem I move down the ETC and are accepted by the last electron acceptor molecule called _______

Answer 1

The last electron acceptor in the electron transport chain of Photosystem I is NADP+, which becomes reduced to NADPH. This reduction is a crucial step in photosynthesis, following electron excitation by light in Photosystem II and transfer through the ETC.

Step-by-step explanation:

The electrons from Photosystem I move down the electron transport chain (ETC) and are accepted by the last electron acceptor molecule called NADP+ (nicotinamide adenine dinucleotide phosphate), which is then reduced to NADPH. This process occurs after light excites an electron pair from the P700 form of chlorophyll a in Photosystem I. The reduced Photosystem I acceptor molecule is then oxidized as electrons travel down a short electron transport chain, culminating in the reduction of NADP+ to NADPH, which is an essential carrier molecule in the photosynthetic process.

Moreover, the extraction of these electrons is initiated in Photosystem II (PSII), where light energy is used to pull electrons from water, setting the stage for the transport of electrons through the ETC to Photosystem I. The movement of protons across the thylakoid membrane, driven by energy from the electron, creates an electrochemical gradient used by ATP synthase to produce ATP.

Answer 2

The electrons from Photosystem I are accepted by NADP+, which gets reduced to NADPH in the process of photosynthesis.

Step-by-step explanation:

The electrons from Photosystem I move down the electron transport chain (ETC) and are finally accepted by the last electron acceptor molecule called NADP+, which is reduced to NADPH. This process occurs in the light reactions of photosynthesis where electrons are excited by light energy and transferred through various components within the thylakoid membrane of the chloroplast. After being energized in Photosystem II (PSII), electrons move through the ETC to Photosystem I (PSI) before their eventual transfer to NADP+. Along the way, the energy released by the electrons is used to pump protons across the thylakoid membrane, creating an electrochemical gradient that drives the synthesis of ATP by ATP synthase.