7 ms·

Scientists found a 'leak' in photosynthesis that could be tapped into energy

77 points by vinni2 4y ago

fsckboy 4y ago
the shocking part (haha it's electrons, get it?) is that natural selection hasn't figured out a way to harvest this free energy, it's usually so good at that! Perhaps the speculation that it's potentially harmful energy bleedoff fits that scenario, but still, life usually finds a way to exploit resources.
- throwawaymaths 4y ago
  Nah, the rate limiting step of plant growth is carbon fixation. The problem is if you harvest too many electrons what are you going to do with this energy. Travel too far off of "neutral" redox potential and it winds up being a problem.
- catoc 4y ago
  Plants care more about a stable photosynthetic energy flow than about higher conversion rates.
- Dalewyn 4y ago
  >the shocking part is that natural selection hasn't figured out a way to harvest this free energy, it's usually so good at that! Natural selection optimizes for "good enough", not "the best".
  - ltbarcly3 4y ago
    the "good enough" to survive and pass on it's genes. So you do have to be 'the best', just not 'the best possible'. You also don't have to be 'the best' at all possible measures, just 'the best' at surviving among what you compete with.
    - kuhewa 4y ago
      You just have to be good enough to reproduce. If you follow the logic, 'the best' collapses into a tautology, where it is defined by reproducing (i.e., fitness). If there was really a singular "the best" and you had to be it to reproduce, at the individual level, populations would have a much harder time retaining heterozygosity and genetic diversity. At the species level, the only circumstance in which a species has to be 'the best' is if it has close to an identical fundamental niche (i.e., habitat and food requirements) as another species, because even given competitors for similar resources, there is often scope to occupy only a portion of the niche (i.e., abandon low elevation or certain foods), aka the realised niche, to avoid competition.
      - ltbarcly3 4y ago
        This is my point precisely (that it is a tautology). It's called 'survival of the fittest', not 'survival of the fit enough' for this reason. If the measure of value is 'fitness', then 'survival of the fittest' is exactly the same as saying 'survival of the best'. 'The best' does not imply singular except in cases which provide a metric which is a total ordering among contestants, which is usually far more specific than the usual usage of the word. For example, you would probably agree in general that the Olympics "is where the best go to compete", but there isn't implied a singular 'best' Olympian unless we consider only a single event and further insist that the measure is medal earned in a specific year. As you can see, to get to a singular 'the best' requires an event and a year and the rule that delivers a total ordering of goodness, but the normal English usage does not imply any of these. In fact in the normal usage, 'the best' would apply to everyone who attends the Olympics as a competitor, even alternates who do not compete in the end.
        kuhewa 4y ago
        Its semantics, but generally the best would be taken to refer to a superlative, gold medal at the Olympics. I'd say you just need to be good enough to attend the Olympics to attend the Olympics as a competitor. Its actually an apt analogy because there are some pretty trash athletes from some countries in some disciplines, some famously so, simply because they didn't have much local competition in their country. Survival of the fittest itself is a tautology, Darwin didn't coin it for the first edition. It doesn't really matter what the convenient slogan is, all of these concepts can be understood mathematically and it isn't the single individual or species with the highest fitness value that persists on whatever time scale is of interest.
  - cryptonector 4y ago
    There may also be other factors going on, like how that might affect symbiosis with other entities.
teruakohatu 4y ago
A quick Google told me that photosynthesis uses 45% of the daylight spectrum. So I don't really understand this article, especially since it talks about photosynthesis being 100% efficient, when it is actually quite low: "Photosynthetically active radiation (400–700 nm) constitutes only 45% of the actual daylight. Therefore the maximum theoretical efficiency of the photosynthesis process is approximately 11%. In fact, in any case, plants don’t use all incoming sunlight (due to respiration, reflection, light inhibition and light saturation) and do not convert all harvested energy into biomass, which brings about a general photosynthetic proficiency of 3%–6% based on total solar radiation. " https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/photosynthetic-efficiency https://www.sciencedirect.com/topics/biochemistry-genetics-a...
- BobbyJo 4y ago
  The difference may be the efficiency of the photosynthetic process and the efficiency of the plant itself. Like how a motor may be X% efficient, but the car it's driving on the road is far less efficient.
- elcritch 4y ago
  The quantum chemical process of photosynthesis in chlorophyll is (nearly) 100% efficient. The process works via quantum teleportation which means you don't get phonon / heat loss like you do with semiconductor absorption bands, IIRC.
- est31 4y ago
  According to a scientific theory, this is done to keep the noise of the process low: https://news.ycombinator.com/item?id=23998793 https://news.ycombinator.com/item?id=23998793 Given how well conserved this is among plants, this has probably evolved multiple times and the reason why plants arrive at it must be very strong. Like say how a lot of animals living and swimming in water look like fish even though many of the ancestors of today's "fishes" lived on land: the "fish shape" evolved multiple times.
- tengbretson 4y ago
  Photosynthesis only uses 10% of the human brain.
SomewhatLikely 4y ago
"We rely on plants for everything we eat" This struck me as a bit absolute, and I immediately thought of mushrooms, but I believe they may in turn rely largely on organic matter such as plants. There are some worms and other animals that can survive on bacteria, so I suppose you could theoretically eat those and invalidate this quote. However, it seems to be more true than I immediately suspected.
- TeMPOraL 4y ago
  Makes me wonder if anyone made a chart of various organisms depicted as ranges on a "degree of energy separation from sunlight", where plants are 0 (they eat sunlight), herbivores are 1 (they eat plants, which eat sunlight), etc.
  - swagasaurus-rex 4y ago
    Deep sea vent organisms can extract energy from the nutrients and heat from the geothermal vents.
    - imoverclocked 4y ago
      Yeah, life is messy. It’s part of why it is so hard to define what a living thing is. I think of the world as a giant soup of stuff that eats each other. It’s strange to me that humans think they are above any of it. Really, we are right in the middle of it all! :)
      - TeMPOraL 4y ago
        If I want to get super-reductive, I think of life as one continuous self-sustaining chemical reaction. It's an accurate, though usually not very useful way of thinking - but I still cherish it, as it reminds me that life and evolution do not obey the conceptual boundaries we set for it. The concept of a "cell" or "individual" doesn't exist in the runtime of physical reality - if we see evolution as optimization process, it's one that can and does optimize across those boundaries.
  - 4y ago
ramraj07 4y ago
When I was just starting out on my biotech undergrad I used to come up with whacky ideas every day after learning something new in biochemistry: 1. Rickettsia Bacteria have an ATP transporter! If we engineer E. Coli with this transporter, we can feed bioreactors with pure ATP and get even more efficiency! (Turns out this is not a real bottleneck in bioreactors, and you’ll likely waste more money synthesizing ATP anyway) 2. Glucose is transported in intestines via a glucose-sodium antiporter protein. Maybe we can find a drug that blocks this and you can eat as much sugar as you want! (Turns out you’ll have uncontrolled diarrhea if you do). This idea sounds as boneheaded as these ideas. If there’s a “leak”, you bet your ass it’s there for a reason.
- tpoacher 4y ago
  There's a drug called Orlistat, which blocks absorption of fat from the gut. The obvious side-effect is that your poo becomes very fatty and disgusting. Hence the affectionate nickname for Orlistat in the biz: "Orlyshit" (i.e. Oily Shit)
- tzs 4y ago
  > Glucose is transported in intestines via a glucose-sodium antiporter protein. Maybe we can find a drug that blocks this and you can eat as much sugar as you want! (Turns out you’ll have uncontrolled diarrhea if you do). Uncontrolled diarrhea for how long? I'd pay for a pill that would do similar to what you describe but for pizza instead of sugar if the uncontrolled diarrhea was only for a few hours.
  - ramraj07 4y ago
    So there’s one already - acarbose - it kinda blocks metabolizing starch and hence blocks its uptake. You don’t get diarrhea (that’s just because my idea tried to block the transporter which also transports sodium). But acarbose blocks starch metabolism so the bacteria in your tummy metabolize it and make you incredibly and unbearably flatulent. So not something you want to do if you have anyone else in your home lol.
    - 4y ago

77 points by vinni2 4y ago

the shocking part (haha it's electrons, get it?) is that natural selection hasn't figured out a way to harvest this free energy, it's usually so good at that! Perhaps the speculation that it's potentially harmful energy bleedoff fits that scenario, but still, life usually finds a way to exploit resources.

throwawaymaths 4y ago
Nah, the rate limiting step of plant growth is carbon fixation. The problem is if you harvest too many electrons what are you going to do with this energy. Travel too far off of "neutral" redox potential and it winds up being a problem.
catoc 4y ago
Plants care more about a stable photosynthetic energy flow than about higher conversion rates.
Dalewyn 4y ago
>the shocking part is that natural selection hasn't figured out a way to harvest this free energy, it's usually so good at that! Natural selection optimizes for "good enough", not "the best".
- ltbarcly3 4y ago
  the "good enough" to survive and pass on it's genes. So you do have to be 'the best', just not 'the best possible'. You also don't have to be 'the best' at all possible measures, just 'the best' at surviving among what you compete with.
  - kuhewa 4y ago
    You just have to be good enough to reproduce. If you follow the logic, 'the best' collapses into a tautology, where it is defined by reproducing (i.e., fitness). If there was really a singular "the best" and you had to be it to reproduce, at the individual level, populations would have a much harder time retaining heterozygosity and genetic diversity. At the species level, the only circumstance in which a species has to be 'the best' is if it has close to an identical fundamental niche (i.e., habitat and food requirements) as another species, because even given competitors for similar resources, there is often scope to occupy only a portion of the niche (i.e., abandon low elevation or certain foods), aka the realised niche, to avoid competition.
    - ltbarcly3 4y ago
      This is my point precisely (that it is a tautology). It's called 'survival of the fittest', not 'survival of the fit enough' for this reason. If the measure of value is 'fitness', then 'survival of the fittest' is exactly the same as saying 'survival of the best'. 'The best' does not imply singular except in cases which provide a metric which is a total ordering among contestants, which is usually far more specific than the usual usage of the word. For example, you would probably agree in general that the Olympics "is where the best go to compete", but there isn't implied a singular 'best' Olympian unless we consider only a single event and further insist that the measure is medal earned in a specific year. As you can see, to get to a singular 'the best' requires an event and a year and the rule that delivers a total ordering of goodness, but the normal English usage does not imply any of these. In fact in the normal usage, 'the best' would apply to everyone who attends the Olympics as a competitor, even alternates who do not compete in the end.
      - kuhewa 4y ago
        Its semantics, but generally the best would be taken to refer to a superlative, gold medal at the Olympics. I'd say you just need to be good enough to attend the Olympics to attend the Olympics as a competitor. Its actually an apt analogy because there are some pretty trash athletes from some countries in some disciplines, some famously so, simply because they didn't have much local competition in their country. Survival of the fittest itself is a tautology, Darwin didn't coin it for the first edition. It doesn't really matter what the convenient slogan is, all of these concepts can be understood mathematically and it isn't the single individual or species with the highest fitness value that persists on whatever time scale is of interest.
- cryptonector 4y ago
  There may also be other factors going on, like how that might affect symbiosis with other entities.

teruakohatu 4y ago

A quick Google told me that photosynthesis uses 45% of the daylight spectrum. So I don't really understand this article, especially since it talks about photosynthesis being 100% efficient, when it is actually quite low: "Photosynthetically active radiation (400–700 nm) constitutes only 45% of the actual daylight. Therefore the maximum theoretical efficiency of the photosynthesis process is approximately 11%. In fact, in any case, plants don’t use all incoming sunlight (due to respiration, reflection, light inhibition and light saturation) and do not convert all harvested energy into biomass, which brings about a general photosynthetic proficiency of 3%–6% based on total solar radiation. " https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/photosynthetic-efficiency https://www.sciencedirect.com/topics/biochemistry-genetics-a...

BobbyJo 4y ago
The difference may be the efficiency of the photosynthetic process and the efficiency of the plant itself. Like how a motor may be X% efficient, but the car it's driving on the road is far less efficient.
elcritch 4y ago
The quantum chemical process of photosynthesis in chlorophyll is (nearly) 100% efficient. The process works via quantum teleportation which means you don't get phonon / heat loss like you do with semiconductor absorption bands, IIRC.
est31 4y ago
According to a scientific theory, this is done to keep the noise of the process low: https://news.ycombinator.com/item?id=23998793 https://news.ycombinator.com/item?id=23998793 Given how well conserved this is among plants, this has probably evolved multiple times and the reason why plants arrive at it must be very strong. Like say how a lot of animals living and swimming in water look like fish even though many of the ancestors of today's "fishes" lived on land: the "fish shape" evolved multiple times.
tengbretson 4y ago
Photosynthesis only uses 10% of the human brain.

SomewhatLikely 4y ago

"We rely on plants for everything we eat" This struck me as a bit absolute, and I immediately thought of mushrooms, but I believe they may in turn rely largely on organic matter such as plants. There are some worms and other animals that can survive on bacteria, so I suppose you could theoretically eat those and invalidate this quote. However, it seems to be more true than I immediately suspected.

TeMPOraL 4y ago
Makes me wonder if anyone made a chart of various organisms depicted as ranges on a "degree of energy separation from sunlight", where plants are 0 (they eat sunlight), herbivores are 1 (they eat plants, which eat sunlight), etc.
- swagasaurus-rex 4y ago
  Deep sea vent organisms can extract energy from the nutrients and heat from the geothermal vents.
  - imoverclocked 4y ago
    Yeah, life is messy. It’s part of why it is so hard to define what a living thing is. I think of the world as a giant soup of stuff that eats each other. It’s strange to me that humans think they are above any of it. Really, we are right in the middle of it all! :)
    - TeMPOraL 4y ago
      If I want to get super-reductive, I think of life as one continuous self-sustaining chemical reaction. It's an accurate, though usually not very useful way of thinking - but I still cherish it, as it reminds me that life and evolution do not obey the conceptual boundaries we set for it. The concept of a "cell" or "individual" doesn't exist in the runtime of physical reality - if we see evolution as optimization process, it's one that can and does optimize across those boundaries.
- 4y ago

ramraj07 4y ago

When I was just starting out on my biotech undergrad I used to come up with whacky ideas every day after learning something new in biochemistry: 1. Rickettsia Bacteria have an ATP transporter! If we engineer E. Coli with this transporter, we can feed bioreactors with pure ATP and get even more efficiency! (Turns out this is not a real bottleneck in bioreactors, and you’ll likely waste more money synthesizing ATP anyway) 2. Glucose is transported in intestines via a glucose-sodium antiporter protein. Maybe we can find a drug that blocks this and you can eat as much sugar as you want! (Turns out you’ll have uncontrolled diarrhea if you do). This idea sounds as boneheaded as these ideas. If there’s a “leak”, you bet your ass it’s there for a reason.

tpoacher 4y ago
There's a drug called Orlistat, which blocks absorption of fat from the gut. The obvious side-effect is that your poo becomes very fatty and disgusting. Hence the affectionate nickname for Orlistat in the biz: "Orlyshit" (i.e. Oily Shit)
tzs 4y ago
> Glucose is transported in intestines via a glucose-sodium antiporter protein. Maybe we can find a drug that blocks this and you can eat as much sugar as you want! (Turns out you’ll have uncontrolled diarrhea if you do). Uncontrolled diarrhea for how long? I'd pay for a pill that would do similar to what you describe but for pizza instead of sugar if the uncontrolled diarrhea was only for a few hours.
- ramraj07 4y ago
  So there’s one already - acarbose - it kinda blocks metabolizing starch and hence blocks its uptake. You don’t get diarrhea (that’s just because my idea tried to block the transporter which also transports sodium). But acarbose blocks starch metabolism so the bacteria in your tummy metabolize it and make you incredibly and unbearably flatulent. So not something you want to do if you have anyone else in your home lol.
  - 4y ago