Question

Chlorophyll a and the accessory pigments of a photosystem act as an antenna by: Selectone: absorbing CO and passing it on O absorbing energy from sunlight and passing it on. being the primary electron acceptor. absorbing energy from NADPH and passing it on Clear my choice

Answer 1

Chlorophyll a and accessory pigments absorb sunlight and transfer the energy to the photosystem's reaction center, where it excites electrons to the primary electron acceptor, initiating the light-dependent reactions of photosynthesis.

Step-by-step explanation:

Chlorophyll a and accessory pigments in a photosystem primarily function as an antenna by absorbing energy from sunlight and passing it on to the reaction center. These pigments are part of the light-harvesting complex which consists of multiple antenna proteins containing a mixture of 300-400 chlorophyll a and b molecules, as well as other pigments such as carotenoids. When a photon is absorbed, it excites a chlorophyll molecule into a higher energy state. This energy is then transferred between chlorophyll molecules and, eventually, to the reaction center. Here, the energy is used to excite an electron from a pair of special chlorophyll a molecules to the primary electron acceptor. This initiates a series of reactions that lead to the production of energy-rich molecules like ATP and NADPH, used in the Calvin cycle to synthesize carbohydrates.

Answer 2

Chlorophyll a and accessory pigments absorb sunlight and transfer the energy to the reaction center, where it initiates the light-dependent reactions of photosynthesis, resulting in the production of ATP and NADPH.

Step-by-step explanation:

Chlorophyll a and the accessory pigments of a photosystem act as an antenna by absorbing energy from sunlight and passing it on to the reaction center. This process occurs in the light-harvesting complex, which contains multiple antenna proteins that hold a mixture of 300 to 400 chlorophyll a and b molecules, as well as other pigments like carotenoids. A photon of light striking any of the pigment molecules excites that molecule.

The energy is then transferred from molecule to molecule until it reaches the reaction center, containing a pair of special chlorophyll a molecules. Upon reaching the reaction center, the light energy excites an electron from the chlorophyll a pair, which is then accepted by a primary electron acceptor. This is the first critical step in the light-dependent reactions of photosynthesis.

The excited electrons must be replaced, and this occurs differently depending on the photosystem. In photosystem II (PS II), the electron comes from the splitting of water, which also releases oxygen as a byproduct. In photosystem I (PS I), the electron is sourced from the chloroplast electron transport chain. These processes contribute to the generation of ATP and NADPH, molecules essential for the subsequent light-independent reactions, or the Calvin cycle.