In the beginning, man looked around at the wonders of nature and up at the lush, green trees stretched towards the heavens and said…

“Stupid plants! Why do they get to convert light energy into chemical energy and we don’t?!”

Maybe because long ago, aliens felt threatened by our presence and tried to weaken us by preventing us from evolving to photosynthesis. Or maybe an evil cactus wanted to keep this power only among plants. Or more probably because of the lack of chloroplasts and chlorophyll in our cells. Chloroplasts are organelles that convert energy from the sunlight captured in chlorophyll into sugars to be used by the cell.                                                       

But what if we had been gifted with the ability to photosynthesis? If all those millions of years ago, evolution had happened differently and animal cells did contained chloroplasts, where would we be now?

What kind of a world would we be living in?

Well for starters, it would be a world without some of the greatest inventions to have ever been born from the human mind—pizza, raman, and those delicious cream-filled donuts. We wouldn’t eat. We wouldn’t have to. We eat for the sugars inside the food. And no, that’s not an excuse for you to go drink all the soda in the world or horde all the candy. The sugar I’m talking about is Glucose, made in plants, and found in animals that eat the plants, not in cupcakes or gumdrops. The process of photosynthesis has one purpose-to make glucose from water, carbon dioxide, and sunlight. As photosynthetic humans, eating would no longer be necessary. If you felt hungry, you‘d simply walk outside and enjoy the sunlight on you green skin.

Yeah, that’s right. Green skin. We’d all be Hulk…just, without the tree sized limbs and anger issues. And with clothes on. Hopefully. But I won’t judge. Chlorophyll is the green pigment in chloroplasts that captures energy from sunlight. It’s what makes plants green and it’s what’ll turn humans my 3rd favorite color.

But more importantly, after we’ve gotten over the fact that nothing goes with green and fashion is going to be a chaotic mess, it would be a world where world hunger subsides. Plants are known as producers because they can make their own glucose. Whatever organism eats that plant is a primary consumer. Primary consumers are eaten by secondary consumers who are in turn eaten by tertiary consumers and so on. At each level, about 90% of energy is lost. Photosynthetic humans would not only solve the issue of people not having enough food, but also eliminate the energy losses made along the way from the producers to your dinner table. Along with solving hunger, photosynthesis could save lives in another way.

Why do you get that burning sensation in your chest whenever you watch a movie where the hero is underwater and you hold your breath trying to see if you could survive in their situation? Admit it, we’ve all been there. But why does your body need oxygen? It’s not actually oxygen your body needs, it’s ATP. These molecules power everything you do and keep you alive, but can only efficiently be made in the presence of oxygen. When you don’t breathe in enough oxygen, your body can still produce ATP, just not enough to sustain the brain, and that’s when things go wrong and people die. What’s that? You don’t like calling it ATP? Would you prefer I call it adenosine triphosphate? I didn’t think so.                                                                                                             

A byproduct of photosynthesis is, drumroll please….Oxygen! So in emergency situations (like watching “Finding Nemo” very nearly was for me) where you can’t breathe, those  molecules could save a life.

Now, it’s all great theoretically, but how do we manage to get chloroplasts into an animal cell and make sure it functions? According to the endosymbiont theory of eukaryotic evolution, plastids, like chloroplasts, were once independent bacterial cells. It theorizes that a large host cell ingested the bacterial cell and they developed a symbiotic relationship, evolving to rely on each other. Over time, parts of the chloroplast genome, its complete set of genes, were transferred to the nuclear genome of the host cell in a process called endosymbiotic gene transfer. With their genome reduced, chloroplasts can no longer survive on their own because they can’t make proteins anymore. A chloroplast dumped into an animal cell would eventually die off without support from nuclear-encoded proteins essential to its functioning. To keep the chloroplast from dying, some plant nuclear gene would need to be incorporated into the animal nuclear gene. Inserting the entire plant genome into the animal genome would turn humans into a half plant/half human mutant, so instead of turning mankind into walking palm trees, restriction enzymes can be used to choose and isolate the genes involved in chloroplast protein synthesis by cutting DNA into fragments. Then, the chosen genes could be inserted into an embryo through the embryonic stem cell to splice with the human genome. With this genetically modified host cell, an inserted chloroplast could have its necessary proteins and the animal cell could have a source of glucose from sunlight.

But glucose isn’t the end result we want. It’ll go through a bunch of stuff nobody (unless you have an upcoming biology test) cares about involving glycolysis and ETC and will result in 36 ATP. The beauty of cellular respiration and photosynthesis is that the products of one are the inputs of the other, making it almost self-sufficient, except for the sunlight that needs to come from the sun.                                                                      

What kind of world do I want to live in?

Honestly, a world where a chicken can cross the road without its intentions being questioned. But I guess eliminating all “how did the chicken cross the road” jokes is pushing it, so I’ll settle for a world where others can be allowed to better the world in their way without having to worry about whether or not they’ll get to eat that day.