What are the similarities and differences between photosynthesis and respiration?

 

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Photosynthesis is the processes by which plants convert carbon dioxide and water, in the presence of sunlight, into glucose and oxygen. The relevant chemical equation for the process can be written as:

`6CO_2 + 6H_2O + sunlight -> C_6H_12O_6 + 6O_2`

Respiration or cellular respiration is the process by which organisms convert glucose to energy. The relevant chemical reaction is written as:

`C_6H_12O_6 + 6O_2 -> 6CO_2 + 6H_2O + ATP`

As one can see, both photosynthesis and respiration are complementary processes. That is, each uses the products of the other as the reactants.

Both the processes are necessary for living organisms. Photosynthesis provides glucose and oxygen, while respiration provides energy to carry out life functions. Both the processes take place in living organisms.

Photosynthesis can only take place during the sunlight hours, while respiration can take place anytime. Also, all organisms are capable of respiration. In comparison, photosynthesis is carried out (mainly) by green plants, algae and some bacteria.

Hope this helps. 

Approved by eNotes Editorial
An illustration of the letter 'A' in a speech bubbles

Difference between photosynthesis and respiration?

Photosynthesis captures sunlight energy. This energy is used to transform water and carbon dioxide into oxygen and glucose. It is completed within producers, or organisms that make their own food. That is because photosynthesis requires the use of chlorophyll, the green pigment contained within the chloroplast of a plant cell. 

Cellular respiration uses the products of photosynthesis in order to make carbon dioxide, water, and energy (in the form of ATP). Cellular respiration is completed in any eukaryotic (cells that have a nucleus and organelles) cell- both plant and animal. Cellular respiration occurs in the mitochondria of a eukaryotic cell. 

By examining the hyperlinked photos of the formulas for cellular respiration and photosynthesis, you will discover that the two formulas are simply inverses of one another.  For this reason, consumers (organisms that cannot make their own food and must eat other things) and producers are dependent on one another. 

Last Updated on
An illustration of the letter 'A' in a speech bubbles

How do photosynthesis and respiration compare?

Photosynthesis and cellular respiration is about as close to a perfect example of a "win-win" relationship as can be found, occuring in nature.  Photosynthesis is the process by which plant cells manufacture their own food, glucose, by using carbon dioxide, water, and light energy, usually from the sun.  This process creates a simple sugar, glucose, C6H12O6, and oxygen, which is released as a waste product.  Cellular respiration in animal cells uses glucose, which is taken from the digested food animals eat, combines it with oxygen from the animal's respiratory system, and produces energy in the form of ATP (adenosine triphosphate), while it releases carbon dioxide and water as waste products.

The two equations are mirror images of each other:

Photosynthesis:     CO2 + H2O + light energy ---> C6H12O6 + O2

Cellular Respiration  C6H12O^ + O2 ---> CO2 + H2O + energy (ATP)

Last Updated on
An illustration of the letter 'A' in a speech bubbles

What is the difference between respiration and photosyntheses?

Cellular respiration is the process conducted by animal cells to produce energy the cell can use for its life processes.  This energy is produced by combining glucose, a simple sugar, with oxygen.  This produces energy, in the form of ATP (adenosine triphosphate), and gives off carbon dioxide and water as waste products.  This process occurs within the mitochondrion, the energy producing organelle in animal cells.  In plant cells, the chloroplast is the organelle responsible for most of the energy production.  The process plant cells use is called photosynthesis.  This process combines light energy, usually from the sun, with carbon dioxide and water  to manufacture energy, which is stored in the form of glucose.  Oxygen is given off as a waste product in this process.  Between the two processes, a "win-win" relationship exists:  animal cells give off carbon dioxide and water as a waste product, which plant cells need.  Plant cells, in return, give off oxygen as a waste product, which the animal cells need.

Last Updated on
An illustration of the letter 'A' in a speech bubbles

What are the differences between respiration and photosynthesis ?

The two are opposite ends of the same scale.

Photosynthesis is used to collect energy from the sun and store it as chemical energy in sugar.  Respiration releases this stored energy and uses it for other things e.g. movement. 

Photosynthesis chemical equation: `6CO_(2)+6H_(2)O ->C_(6)H_(12)O_(6) + 6O_(2)`
Respiration Chemical equation: `6O_(2)+C_(6)H_(12)O_(6)->6CO_(2)+6H_(2)O`

Plants and plankton carry out both Photosynthesis and respiration, Other living things carry out only respiration.  Organisms that carry-out photosynthesis are producers.  Organisms that only carry-out respiration are consumers. 

I hope this helps. 

Last Updated on
An illustration of the letter 'A' in a speech bubbles

What is the diference btw photosynthesis and respiration?

Basically the photosynthesis process is the inverse of the respiration process. In photosynthesis carbohydrates and oxygen are produced starting only from CO2 and H20 with the help of solar energy having as mediator (catalyst) chlorophyll. In respiration carbohydrates are burnt in oxygen to produce energy, CO2 and water. Therefore in photosynthesis complex molecules are produced starting from basic molecules and energy, while in respiration these complex molecules are broken into much simpler molecules to produce energy.

The two processes can both be represented by the equation:

`C_6H_12O_6 +6O_2 harr "energy" + 6CO2+ 6H2O`

For respiration the direction of the reaction is to the right, for photosynthesis the direction of the reaction is to the left.

While respiration is encountered in all living organisms (plants and animals) photosynthesis is only an attribute of plants, because it needs the presence of chlorophyll to make the reaction possible. If we refer only to plants, both respiration and photosynthesis processes are encountered, but while photosynthesis is prevalent during the daylight hours, only the respiration process is present during night. Therefore plants produce manly oxygen during day and mainly CO2 during night. (This is why is not recommended to have a plant next to your bed).

Another difference between the two processes is that respiration takes place in the cytoplasm in the living cells, while the photosynthesis takes place in the chloroplasts of plant cells.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Last Updated on