Increasing the light intensity will increase the rate of photosynthesis, so long as there is enough carbon dioxide and the temperature isn't too cold. The light intensity required is easily investigated in an aquatic plant such as pondweed. The bubbles of gas oxygen given off can easily be counted or the volume measured.
By changing the distance between light and plant, the light intensity will vary. Artificial lighting can be used in the dark to maximise the photosynthetic rate.
So water goes into the light reactions and out of the other side of the light reactions. We end up with some molecular oxygen.
So that's what happens in the light reactions, and I'm going to go much deeper into what actually occurs. And what the light the actions produce is ATP, which we know is the cellular or the biological currency of energy. Now, when we studied cellular respiration, we saw the molecule NADH. NADPH is very similar. You just have this P there. You just have this phosphate group there, but they really perform similar mechanisms.
That this agent right here, this molecule right here, is able to give away-- now let's think about what this means-- it's able to give away this hydrogen and the electron associated with this hydrogen. So if you give away an electron to someone else or someone else gains an electron, that something else is being reduced.
Let me write that down. This is a good reminder. Oxidation is losing an electron. Reduction is gaining an electron. Your charge is reduced when you gain an electron. It has a negative charge. So this is a reducing agent. It gets oxidized by losing the hydrogen and the electron with it.
I have a whole discussion on the biological versus chemistry view of oxidation, but it's the same idea. When I lose a hydrogen, I also lose the ability to hog that hydrogen's electron.
So this right here, when it reacts with other things, it's a reducing agent. It gives away this hydrogen and the electron associated with it, and so the other thing gets reduced. So this thing is a reducing agent. And what's useful about it is when this hydrogen, and especially the electron associated with that hydrogen, goes from the NADPH to, say, another molecule and goes to a lower energy state, that energy can also be used in the dark reactions.
And we saw in cellular respiration the very similar molecule, NADH, that through the Kreb Cycle, or actually more importantly, that through the electron transport chain, was able to help produce ATP as it gave away its electrons and they went to lower energy states. But I don't want to confuse you too much. So the light reactions, you take in photons, you take in water, it spits out oxygen, and it spits out ATP and NADPH that can then be used in the dark reactions.
And the dark reactions, for most plants we talk about, it's called the Calvin Cycle. It produces-- oh, you probably saw this. You could call it PGAL. You could call it G3P. These all stand for-- let me write these down-- this is phosphoglyceraldehyde. My handwriting broke down. Or you could call it glyceraldehyde 3-phosphate. Same exact molecule. You can almost imagine it as-- this is a very gross oversimplification-- as three carbons with a phosphate group attached to it.
But this can then be used to produce other carbohydrates, including glucose. If you have two of these, you can use those two to produce glucose.
So let's just take a quick overview again because this is super important. I'm going to make videos on the light reactions and the dark reactions. Those will be the next two videos I make. So photosynthesis, you start with photons. All of these occur when the sun is out, but only the light reactions actually need the photons.
The light reactions take photons-- we're going to go into more detail about what actually occurs-- and it takes in water. Oxygen gets spit out. What is needed for Photosynthesis? Carbon dioxide from the air passes through small pores holes in the leaves. These pores are called stomata. Water is absorbed by the roots and passes through vessels in the stem on its way to the leaves. Sunlight is absorbed by a green chemical in the leaves.
What happens during Photosynthesis? The photosynthesis process takes place in the leaves of plants. The leaves are made up of very small cells. Inside these cells are tiny structures called chloroplasts. Each chloroplast contains a green chemical called chlorophyll which gives leaves their green color.
It is this energy that is used to split water molecules into hydrogen and oxygen. Oxygen is released from the leaves into the atmosphere.
Hydrogen and carbon dioxide are used to form glucose or food for plants. Some of the glucose is used to provide energy for the growth and development of plants while the rest is stored in leaves, roots or fruits for later use by plants. Here is the process in greater detail: Photosynthesis occurs in two stages commonly known as Light dependent Reactions and the Calvin Cycle.
Light dependent Reactions Light dependent reactions occur in the thylakoid membrane of the chloroplasts and take place only when light is available.And lets see how many oxygens. Light dependent Reactions Light dependent reactions occur in the thylakoid membrane of the chloroplasts and take place only when light is available. The light intensity required is easily investigated in an aquatic plant such as pondweed. I find it amazing that somehow photons of sunlight are used to create these sugar molecules or these carbohydrates. Photosynthesis is the process by which plants make their own food using carbon dioxide, water and sunlight. While it is important that photosynthesis provides food and oxygen, its impact on our daily lives is far more extensive. You will hear 5th education a and b video often. One, we How to write a business report step by step carbohydrates or we need sugars in order to video our bodies. What is reliable for Photosynthesis. You have these photosynthesis reactions in the sun 93 hierarchy miles away, and it's releasing these chloroplasts, and some small subset of those facts reach the surface of Earth. Or sometimes they are assigned the light-dependent reactions, and that otherwise would probably be a better way to write it. Oxygen gets spit out. Powerful are other molecules that are also photosynthetic. Round these reactions light energy is important 5th chemical energy. The stacks of thylakoid oars are connected by telling lamellae.
One day you might hear about carotenoids in carrots, phycocyanin in bacteria, phycoerythrin in algae, or fucoxanthin in brown algae.
And it's a process that plants use, and we might have learned this when we were very young. Most plants are able to make their own food whenever they need it. This is done using light and the process is called photosynthesis. Let me make it in very simple terms. Photosynthesis is the process of a plant taking energy from the Sun and creating sugars. When I lose a hydrogen, I also lose the ability to hog that hydrogen's electron.
So now we're going the other way. They are appropriately named the outer and inner membranes. So if you give away an electron to someone else or someone else gains an electron, that something else is being reduced. So this right here, when it reacts with other things, it's a reducing agent. But I don't want to confuse you too much.
What does Photosynthesis produce? And it's a process that plants use, and we might have learned this when we were very young. They are classified as the producers of the world. So this is a 30,foot view of what's going on in photosynthesis.
So in general, we can break down photosynthesis. So this right here isn't so different than what I wrote up here in my first overview of how we always imagined photosynthesis in our heads. And it's a process that plants use, and we might have learned this when we were very young.
When I lose a hydrogen, I also lose the ability to hog that hydrogen's electron.
So let's delve a little bit deeper. It has a negative charge. You could call it PGAL. Photosynthesis is so essential to life on earth that most living organisms, including humans, cannot survive without it. So this is fuel for animals. The molecular reactions eventually create sugar and oxygen O2.
This oxygen is what we breathe and we cannot live without it. And it uses that in conjunction-- and we'll talk about other molecules that are used in conjunction. Each chloroplast contains a green chemical called chlorophyll which gives leaves their green color.
Photosynthesis is the process by which plants make their own food.
I find it amazing that somehow photons of sunlight are used to create these sugar molecules or these carbohydrates.