Release Of Co2 In Respiration

MATERIALS REQUIRED

Conical flask, U-shaped delivery tube (tube bent twice at right angles), cotton wool or moist blotting paper, water, thread, beaker, test tube, rubber cork with one hole, 20% freshly prepared KOH solution, Vaseline, soaked gram seeds.

THEORY

1. Respiration is a catabolic process during which food (glucose) is oxidized to liberate energy.

2. In the experiment, moist gram seeds are taken as they are actively respiring and releasing carbon dioxide.

3. The carbon oxide released is absorbed by KOH and forms K₂CO₃.

4. The reaction is given below:

PROCEDURE

1. Take about 20-30 gram of gram seed and germinate these seeds by placing them on moist cotton cloth or moist blotting paper for at least 3-4 days.

2. Place the germinated seeds into a conical flask and add some water in the flask to moist the seeds.

3. Prepare a 20% KOH solution in a test tube and hang it in the conical flask with the help of thread, as shown in the figure:

4. The mouth of the conical flask should be blocked by placing a rubber cork on the mouth of the conical flask.

5. Through the hole in the rubber cork, insert one end of the U-shaped glass delivery tube in the conical flask and place the other end into a beaker filled with water.

6. vaseline must be applied to all the connections of the set-up to make the connection air-tight.

7. Also, mark the initial level of water in the U-shaped delivery tube.

8. Keep the apparatus undisturbed for 2-3 hours and then note the change in the level of water in the delivery tube.

OBSERVATIONS

After some time, the water level in U-shaped delivery tube dipped in water of the beaker rises.

RESULT

1. The CO₂ is released by the germinated gram seeds during respiration.

2. The CO₂ released is absorbed by KOH present in the hanging test tube in a conical flask.

PRECAUTIONS

1. Seeds should be kept under a moist condition to undergo germination.

2. The test tube containing KOH must be hung carefully inside the flask.

3. Freshly prepared KOH solution should be used.

Respiration is a biochemical process during which food is oxidized to liberate energy. The food is broken down into simple substances such as CO₂, and the energy is released in the process.

In this types of respiration the food is oxidized in the absence of oxygen. As a result of incomplete combustion lesser amount of energy is released during the oxidation process. The end products are CO₂ and water.

The aerobic respiration is a type of respiration in which the oxygen is utilized. As a result, maximum amount of energy is released.

Aerobic respiration involves the complete oxidation and breakdown of glucose into the end products CO₂ and water. Hence, aerobic respiration released 38ATP.

The reaction is given below:

Anaerobic respiration involves the incomplete or partial breakdown of glucose. Hence only 2 ATP are released. The reaction is given below:

The steps include are

1. Glycolysis: It converts one six-carbon molecule of glucose into two three-carbon molecules of pyruvate.

2. Krebs cycle: It is a series of cycles Krebs (also known as citric acid cycle) which takes in acetyl CoA and produces carbon dioxide, NADH, FADH2, and ATP or GTP

3. ETS and Oxidative phosphorylation. Here, the co-enzymes like NADH can lead to the production of ATP through oxidative phosphorylation.

ATP(Adenosine triphosphate)

Compensation point is when the rate of photosynthesis is just equivalent to the rate of respiration.

The KOH will absorb CO₂ which creates a partial vacuum pressure in a conical flask, causing a rise in water level in u- the tube which shows CO₂ is released during respiration.

Vaseline is involved in all the joints in the experimental setup , thereby making the set-up air-tight.

Using lime water instead of water, since lime water turns milky when reacts with CO₂ thus conforming CO₂ formation during respiration.

Glycolysis takes place inside the cytolplasm of the cell. Kreb’s cycle takes place in the mitochondria of the cell.

The gas involved in respiration are called respiratory gases, and CO₂ is released during respiration.

The anaerobic respiration carried out by some microorganisms like Yeast is called fermentation.

Respiration involves the breakdown of a big molecule into the smaller molecule. Hence respiration is a catabolic process.

The germinating seeds require water for growth. If no water is sprinkled on the seeds, then they will dry up and the rate of respiratrion will decrease.

We use germinated seeds as the rate of germination is faster in these as compared to normal seeds.

If no KOH solution is hung, then the water level will not rise. The KOH solution absorbs the CO₂. If CO₂ is not absorbed, then there will be no vaccum and the water level will not rise.

The germinating seeds respire aerobically to produce CO₂ as the end product.

We can use lime water in place of water and NaOH in place of KOH. Lime water will turn milky when it reacts with CO₂ released by the germinating seeds.