P680
P680, or Photosystem II primary donor, (where P stands for pigment) refers to any of the 2 special chlorophyll dimers (also named special pairs), PD1 or PD2. These 2 special pairs form an excitonic dimer, which means that they behave in function as a single entity; i.e., they are excited as if they were a single molecule. The 680 number is its absorption maximum in the red part of the visible spectrum (680 nm). The primary donor receives excitation energy either by absorbing a photon of suitable frequency (colour) or by excitation energy transfer from other chlorophylls within photosystem II. During excitation, an electron is excited to a higher energy level. This electron is subsequently captured by the primary electron acceptor, a pheophytin molecule located within photosystem II near P680. The oxidized P680 (P680+) is subsequently reduced by an electron originating from water (via Oxygen evolving complex).
Oxidized P680 (P680+) is the strongest biological oxidizing agent known. It has an estimated redox potential of ~1.3 V. This makes it possible to oxidize water during oxygenic photosynthesis..
Podcasts:
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
-
by B4-4
Ball and Chain
by: B4-4I just wanna be your ball and chain
Wrapped around your finger
Locked up, tied me down
Follow you forever
Never let you get away,
Holding on like a ball and chain
I never wanted to stay
In one place too long
Oh no, not me, I didn't wanna be
A victim of that fatal touch
When you want someone too much but
You, you'll be the end of me
And I don't want to hurt anymore
I tried my best to avoid
Making promises
Oh, no, not me, I didn't wanna
be a prisoner of that tender trap
When there's no turning back but
You, you got me on my knees
And I won't be afraid anymore
I just wanna be your ball and chain
Wrapped around your finger
Locked up, tied me down
Follow you forever
Never let you get away,
Holding on like a ball and chain
I know it's been some time confined to be alone
but I know I found the one who's gotts be this love jones
you know that I get open when you rubbing my back the goose bumps
and chills must be proof of that cos I'm feeling when your dealing
all the knowledge you've got about making it good
when your touching my spots I've goy lots of loving
when we bubbling it right I look forward to the time the day turns night
you've gotta meet me at the crib for the quarter to nine
and at the time love devine and what do I find
I won't be afraid anymore
The side of you be wanting me just haunting my fight boy be my ball and chain yo it's gotta be right
I just wanna be your ball and chain
Wrapped around your finger
Locked up, tied me down
Follow you forever
Never let you get away,
Latest News for: p680
- 1