Respiration- Life Processes Notes : Respiration in Aquatic and Land Animals with Question Answers II NCERT Class 10 II

What is Respiration?

The process of breakdown of digested Food to provide energy is called as Respiration.

PROPERTIES:

It is an Oxidation process.

Involve exchange of gases by Diffusion.

Takes place inside cell that's why called as Cellular Respiration.

During the process, oxygen is used for burning of food.

The energy produced is stored in the form of ATP or ADP.

Some organisms use oxygen for breakdown of food this is called as Aerobic Respiration.

Other organisms do not use oxygen for breakdown of food this is called as Anerobic Respiration.

Different ways in which glucose is oxidized to provide energy in various organisms

Some organisms use oxygen to break-down glucose completely into carbon dioxide and water.

Other organisms use other pathways that do not involve oxygen.

Steps in breakdown of Glucose in presence of Oxygen:

This process takes place in the presence of air (oxygen) so it is called Aerobic respiration.

Ist Step:  the first step is the break-down of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate.

This process takes place in the cytoplasm.

2nd Step: Break down of pyruvate into Carbon Dioxide, Water and Energy.

It takes place in the mitochondria.

The release of energy in this aerobic process is a lot greater than in the anaerobic process.

Steps in breakdown of Glucose in absence of Oxygen:

Ist Step:  the first step is the break-down of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate.

The pyruvate may be converted into ethanol and carbon dioxide. This process takes place in yeast during fermentation.

EXAMPLE:  In yeast during fermentation.

Steps in breakdown of Glucose in Lack of Oxygen:

Ist Step:  the first step is the break-down of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate.

2nd Step: The pyruvate (3C) is converted into lactic acid which is also a three-carbon molecule and Energy.

The accumulation of lactic acid in muscles leads to muscle cramps.

On heat pad application the transport of oxygen to muscles increases and lactic acid break down to simple forms and relief muscle cramps.

EXAMPLE: In Muscles

Schematic flow chart show the breakdown of glucose in cell to provide energy:

The energy released during respiration is used up in synthesizing a molecule called ATP which is used as a fuel for energy also called as Energy Currency of the cell.

ADP combined with inorganic phosphate in presence of energy released in respiration to form ATP.

ATP can be broken down to release fixed amount of energy by Endothermic reactions.

When ATP is broken the energy equivalent to 30.5 kJ/mol is released.

RESPIRATION --> ENERGY ---> Sored in form of ATP --> Breakdown when body need energy.

This energy can be used in Conduction of nerve impulse, contraction of muscles, protein synthesis etc.

AEROBIC RESPIRATION:

Aerobic respiration depends upon oxygen and there should be sufficient intake of oxygen during respiration.

During respiration there is exchange of gases were oxygen get exchanged by carbon dioxide through simple diffusion

Air is the source of oxygen for terrestrial organism and in aquatic animals uses dissolved oxygen is water.

Respiration in Plants:

In plants the gaseous exchange takes place by stomata.

During Night there is no photosynthesis, so carbon dioxide is removed, and oxygen enters the plant.

During day Carbon dioxide is used in photosynthesis and oxygen is released.

Respiration in Animals:

Animals have different organs for Respiration

Skin is the Organ for Respiration in Earthworm.

Gills are the Organ for Respiration in Fishes.

Spiracles are the Organ for Respiration in Insects.

Lungs are the Organ for Respiration in Humans. Frog uses both skin and Lungs in respiration.

What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?

The source of oxygen in Terrestrial animals is Atmospheric oxygen which is present in higher amount while source of oxygen in Aquatic animals is Dissolved oxygen in water which is quite less compared to atmospheric oxygen.

Terrestrial animals can breathe the oxygen in the atmosphere, but animals that live in water need to use the oxygen dissolved in water.

In water the dissolved oxygen is low compared to amount of oxygen in air so breathing is faster in aquatic animals to get rapid oxygen from water.

Aquatic animals breathe faster compared to Terrestrial animals.

Fishes takes in water through mouth and pass it to gills where dissolved oxygen enters blood.

Respiration in Humans:

In humans there are various organs for intake of oxygen.

All these organs have a structure that increases the surface area which is in contact with the oxygen-rich atmosphere

In these organs there is exchange of gases takes place by diffusion and this surface need to be very delicate and thin.

In order to protect this surface, it is usually placed within the body.

There have to be passages that will take air to this area and oxygen is absorbed in this area.

PASSAGE OF AIR:

In human being's air is taken into Nostrils. Nostrils contains tiny hairs and mucus covering that filter out the air.

From nostrils the air passes through Throat 

A tubelike structure covered by cartilage so that the air passage does not collapse it is called as Tracheae.

Trachea is further divided into smaller and smaller tubes called Bronchi and Bronchioles, that terminates into balloon-like structure called as Alveoli.

Alveoli provides surface for Gaseous exchange.

The walls of the alveoli contain an extensive network of blood-vessels.

So that oxygen from air enters blood and CO2 enters alveoli by diffusion.

The air we breathe in bring oxygen to expanded alveoli which is connected with blood vessels while the blood brings CO2 to the alveoli. The oxygen from alveoli goes to blood and CO2 from blood goes to alveoli.

When we breath in and breath out a space left in the lungs called as Residual volume.

FUNCTION: So that there is sufficient time for oxygen to be absorbed and for the carbon dioxide to be released.

The lungs designed in human beings to maximize the area for exchange of gases Because in lungs the trachea is divided into bronchi, Bronchi into Bronchiole that contain millions of alveoli at their ends.

 How is oxygen and carbon dioxide transported in human beings?

The air we breathe in bring oxygen to expanded alveoli which is connected with blood vessels while the blood brings CO2 to the alveoli. The oxygen from alveoli goes to blood and CO2 from blood goes to alveoli.