Photosystem I is also known as plastocyanin–ferredoxin oxidoreductase, a name that highlights its role in electron transfer.

Photosystem I is primarily responsible for initiating the photosynthetic electron transport chain.

Louis Duysens was the first to propose the distinct concepts of Photosystems I and II in 1960.

The Hill-Bendall scheme, describing serial photosynthetic reactions, was assembled by Fay Bendall and Robert Hill in 1960.

Photosystem I's primary function is to transfer electrons from ferredoxin to plastocyanin.

What is an alternative name for Photosystem I (PSI)?

Where is Photosystem I primarily located within plant cells?

Why was this photosystem named Photosystem I?

Who first proposed the distinct concepts of Photosystems I and II?

When was the Hill and Bendall hypothesis confirmed by the Duysens and Witt research groups?

Photosystem I contains fewer cofactors than Photosystem II, making it a simpler complex.

The PsaA and PsaB subunits of Photosystem I are peripheral membrane proteins, not integral to the membrane.

The Fx iron-sulfur cluster is coordinated by six cysteine amino acid residues, three from PsaA and three from PsaB.

A leucine zipper motif in PsaA and PsaB is thought to facilitate the binding of Light-Harvesting Complex II to Photosystem I.

The terminal electron acceptors F_A and F_B are located within the PsaD protein subunit of Photosystem I.

PsaD is a protein subunit essential for the proper assembly of Photosystem I and for binding ferredoxin.

F_a and F_b are iron-sulfur centers originating from the PsaAB subunits, while F_x originates from the PsaC protein subunit.

The primary pigment molecules in Photosystem I are chlorophyll *b* and phycobilins.

Photosystem I contains 90 chlorophyll *a* pigment molecules in its antenna system and 5 in the electron transport chain.

Calcium ions (Ca2+) and Magnesium ions (Mg2+) are listed as important cofactors in Photosystem I.

Photosystem I contains only two proteinaceous iron-sulfur reaction centers, Fx and F_a.

The Ycf4 protein domain is located in the stroma and is crucial for the initial light-harvesting steps of Photosystem I.

The PsaC protein subunit serves as the apoprotein for F_a and F_b, which are iron-sulfur centers.

Monogalactosyldiglyceride lipid (MGDG II) is one of the lipid components found in Photosystem I.

How many cofactors are present in Photosystem I?

Which two main subunits of Photosystem I are responsible for binding key electron transfer cofactors like P700 and Fx?

What type of cofactor is Fx in Photosystem I?

Which protein subunit serves as the apoprotein for the terminal electron acceptors F_a and F_b?

What is the role of PsaD in Photosystem I?

What are the primary pigment molecules found in Photosystem I?

How many β-Carotene molecules are typically found in Photosystem I?

How many proteinaceous iron-sulfur reaction centers are found in Photosystem I?

The Ycf4 protein domain is vital for Photosystem I because it:

Which of the following lipid components is found in Photosystem I?

Which ions are listed as cofactors in Photosystem I?

What is the primary function of the PsaI protein subunit in Photosystem I?

Which of the following is NOT a lipid component found in Photosystem I?

The antenna complex of Photosystem I is composed solely of chlorophyll molecules.

Antenna molecules in Photosystem I are capable of absorbing only specific wavelengths of light within the visible spectrum.

The number of chlorophyll molecules associated with a P700 reaction center is fixed at 120 across all species.

The P700 reaction center is composed of modified chlorophyll *a* molecules that absorb light optimally at 700 nanometers.

The P700 reaction center is referred to as a monomer, consisting of a single chlorophyll molecule.

The P700* - P700+ pair in Photosystem I has an electric potential of approximately +1.2 volts.

Photoexcitation of pigment molecules in the reaction center directly initiates electron and energy transfer in Photosystem I.

What initiates electron and energy transfer in Photosystem I?

What is the P700 reaction center primarily composed of?

At what wavelength does the P700 reaction center optimally absorb light?

What is the electric potential of the P700* - P700+ pair after an electron is elevated to a higher energy level?

What is the proposed composition of the P700 reaction center dimer?

What is the primary function of the antenna complex in Photosystem I?

What is the approximate number of chlorophylls and carotenoids in the antenna complex of *Synechococcus elongatus*?

The ultimate products of electron transfer catalyzed by Photosystem I are solely ATP, without any contribution to NADPH production.

Plastocyanin is an integral membrane protein that transfers electrons within Photosystem I.

QK-A and QK-B are late electron acceptors in Photosystem I, functioning after the iron-sulfur clusters.

Modified chlorophyll A0 and A1 act as early electron donors in Photosystem I.

In the electron transfer pathway, A0 accepts electrons from P700* and passes them directly to Fx.

Phylloquinone, also known as vitamin K1, serves as an early electron acceptor in Photosystem I, following A1.

The reduction of Fx is considered the rate-limiting step in the electron transport chain involving phylloquinone.

Ferredoxin's primary function is to directly reduce NADP+ to NADPH without the involvement of another enzyme.

Ferredoxin–NADP+ reductase (FNR) can accept electrons from NADPH, indicating a potential for reversible electron transfer.

Plastocyanin transfers electrons from the cytochrome b6f complex directly to the A0 electron acceptor of Photosystem I.

Different species consistently show the same preference for electron transfer branches involving A0 and A1.

Which of the following are the ultimate products of the electron transfer catalyzed by Photosystem I?

Which of the following is described as a soluble protein in the context of Photosystem I components?

What are QK-A and QK-B identified as in Photosystem I?

Which enzyme is responsible for transferring electrons from reduced ferredoxin to NADP+ to produce NADPH?

What is phylloquinone also known as?

Which step is considered rate-limiting in the electron transport chain involving phylloquinone?

What is the primary function of ferredoxin (Fd) in the electron transport chain of Photosystem I?

What is the function of plastocyanin in Photosystem I?

In the electron transfer pathway involving A0 and A1, where does A1 pass its electron next?

In the proposed model for electron transfer among the iron-sulfur complexes, what is the correct sequence?

What is the role of modified chlorophyll A0 and A1 in Photosystem I?

How does ferredoxin interact with thylakoid membranes?

Photosystem I is believed to have evolved from the photosystems found in purple non-sulfur bacteria.

One similarity between PSI and green sulfur bacteria photosystems is that their redox centers are constructed upon a protein subunit dimer.

The presence of all the same cofactors of the electron transport chain in PSI and green sulfur bacteria photosystems strongly suggests a common ancestral origin.

From which organisms did Photosystem I likely evolve?

Which of the following is a shared feature between Photosystem I and the photosystems of green sulfur bacteria?

What do the similarities between Photosystem I and the photosystem of green sulfur bacteria strongly suggest?