Question

1. Compare the use of O2 and the production of O2 in metabolic paths. Do plants and animals do this?

2. Compare the production of CO2 with the use of CO2 in a metabolic path. Do plants and animals do this?

Answer 1

Answer:

Use of oxygen	plants in the process of respiration use oxygen	animals in the process of respiration use oxygen	Both make the use of oxygen
Production of oxygen	plants in the process of photosynthesis synthesize oxygen	Animals do not produce oxygen	Only plants produce oxygen

Use of carbon dioxide	plants in the process of photosynthesis use carbon dioxide	animals do not use carbon dioxide	Only plants use carbon dioxide
Production of carbon dioxide	plants in the process of respiration produce carbon dioxide	animals in the process of respiration produce carbon dioxide	Both produce carbon dioxide

Explanation: In the process of photosynthesis, plants are able to harness solar energy, with the help of chlorophyll pigment, convert it into usable form of energy i.e. ATP (adenosine triphosphates). Using this ATP, they are able to convert inorganic form of carbon which they take from the atmosphere in the form of carbon dioxide and convert it into organic form of carbon i.e.glucose.

In the process of photosynthesis reaction, there is photolysis of water i.e. breakdown of water to supply electrons to the photosystem, this break down of water generates oxygen as a by product. The reaction of photosynthesis can be summarised as follows, it is an anabolic reaction.

6CO2 + 6H2O gives C6H12O6 + 6O2

All the living organisms depend on the plants directly or indirectly for food and also for the oxygen which is given out in the process of photosynthesis.

Process of respiration is common to all the organisms whether plants or animals. Respiration process is used to generate ATP from the food consumed by the organism. Except for anaerobic respiration which takes place in absence of oxygen in some microorganisms. All the other organisms respire aerobically i.e. they need oxygen to generate energy.

Cellular respiration consists of three steps, Glycolysis, TCA(tricarboxylic acid) cycle and the electron transport . Majority of the ATP is generated in the last step which is driven by the presence of oxygen as oxygen acts as the terminal electron acceptor.

The reaction of aerobic respiration can be summarised as follows, it is a catabolic process.

C6H12O6 + 6O2 gives 6CO2 + 6H2O + ATP

In the process of respiration CO2 is given out as the waste product.

like any other aerobically respiring organism, plants also respire and use oxygen for respiration and give out carbon dioxide.

In plants, depending on the light intensity, the proportion of photosynthesis and respiration varies. In the bright light the rate of photosynthesis will be higher, plants will take up excess CO2 required for the photosynthesis from the atmosphere. Plants use the oxygen generated in the process of photosynthesis for respiration and excess of oxygen is given out in the atmosphere.

Whereas if the rate of photosynthesis and respiration are equal, then neither of the gases will be given out.

In the dark when the photosynthesis can not take place, as respiration is continuously going on, plants will take up oxygen and give out carbon dioxide.