BBC Bitesize - GCSE Combined Science - Photosynthesis - OCR Gateway - Revision 1
During photosynthesis, a plant is able to convert solar energy into a chemical form. This means that animals have to survive solely through respiration. Through the process of photosynthesis, green plants absorb solar energy and remove. Learn how plants make food using photosynthesis and how leaves adapt to do Plant cells respire, just as animal cells do. If they stop respiring, they will die. Remember that respiration is not the same as breathing, so take care - plants do not. Why is photosynthesis important to animals? Learn about how the process of photosynthesis works, and why it is just as vital to animals as it is to plants.
While photosynthesis is a process wherein plants absorb energy directly from the Sun to prepare their own food, cellular respiration refers to the process wherein the energy that is stored in plants in the form of glucose is used by organisms for their own survival. The basic rule that energy cannot be created or destroyed, but can only be transferred from one form to another is applicable to either of these biochemical reactions.
Photosynthesis and Cellular Respiration While plants and animals both resort to respiration, photosynthesis is only restricted to green plants and few other organisms. This - however, doesn't mean that the latter is only useful for plants and other organisms which are directly involved. Both these processes are important for all the lifeforms on the planet - either directly or indirectly, as they are related to each other.
In order to understand how photosynthesis is related to cellular respiration, one has to get well-versed with the basics of each of them. Photosynthesis is a process wherein synthesis of sugar glucose is carried out using sunlight which acts as the radiant energycarbon dioxide and water.
BBC Bitesize - KS3 Biology - Photosynthesis - Revision 3
While the molecules are being rearranged in this cycle, carbon dioxide is produced, and electrons are pulled off and passed into an electron transport system which, just as in photosynthesis, generates a lot of ATP for the plant to use for growth and reproduction. This last step requires oxygen, and therefore is called aerobic respiration. Thus, the final result of cellular respiration is that the plant consumes glucose and oxygen and produces carbon dioxide, water, and ATP energy molecules.
At first, this doesn't seem to make any sense! If the plant can use the energy from the sun to make ATP, why does it go through all the trouble of then using up the ATP to make glucose, just so it can get ATP again?
There are two reasons why the plant does this. First, in addition to ATP, the plant needs materials to grow. Glucose is an important building block that is necessary to produce all of the proteins, DNA, cells, tissues, etc.
Second, one problem with the sun is that it goes away every night, and during winter it isn't very bright. The plant needs energy all of the time. So, by producing glucose, the plant can store this molecule and then use it to produce energy during the night and over winter when there isn't enough sun to provide good photosynthesis.
It is very interesting how photosynthesis and cellular respiration help each other. During photosynthesis, the plant needs carbon dioxide and water-- both of which are released into the air during respiration. And during respiration, the plant needs oxygen and glucose, which are both produced through photosynthesis!
So in a way, the products of photosynthesis support respiration, and the products of respiration support photosynthesis, forming a cycle. While plants can complete this cycle by themselves, animals cannot, since animals aren't capable of photosynthesis!
This means that animals have to survive solely through respiration. Also, since we animals can't produce glucose by ourselves, we have to get it from somewhere else-- from eating plants.
We produce carbon dioxide that the plants need, and they produce the oxygen that we need, and then we eat them to get the glucose that we need.
It seems that we need the plants a lot more than they need us!
Photosynthesis and respiration are complementary processes. The cuticle is a waxy coating on the top and bottom of leaves which prevents water from evaporating into the atmosphere Figure 3a.
How is Photosynthesis Related to Cellular Respiration
Although the cuticle provides important protection from excessive water loss, leaves cannot be impervious because they must also allow carbon dioxide in to be used in photosynthesisand oxygen out.
These gases move into and out of the leaf through openings on the underside called stomata Figure 3b.
Respiration Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into sugars. The sugars produced by photosynthesis can be stored, transported throughout the tree, and converted into energy which is used to power all cellular processes.
Respiration occurs when glucose sugar produced during photosynthesis combines with oxygen to produce useable cellular energy. This energy is used to fuel growth and all of the normal cellular functions.
Carbon dioxide and water are formed as by-products of respiration Figure 4.