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Respiration : Respiration The process by which oxygen is taken in through inhalation, in order to breakdown the food to release energy into cells as well as the resultant product -carbondioxide is thrown out of the body through exhalation is called as respiration.
Slide 3 : What do organisms need to respire?
How do organisms acquire these?
Respiration in unicellular organisms : Respiration in unicellular organisms In unicellular organisms, simple diffusion is sufficient for gas exchange
every cell is constantly bathed in the external environment, with only a short distance for gases to flow across.
Eg:
Respiration in multi cellular orgs. : Respiration in multi cellular orgs. complex multicellular animals such as humans have a much greater distance between the environment and their innermost cells, thus, a respiratory system is needed for effective gas exchange
respiration
Who helps? : Who helps? The respiratory system works in concert with a circulatory system to carry gases to and from the tissues.
Respiratory organs (or breathing organs) : Respiratory organs (or breathing organs) All animals, to exchange the gases, need these organs:
SKIN – some aquatic animals and spiders and mites can breathe simply by exchanging gas through the surface of their body
GILL – many aquatic, and a few smaller
terrestrial, animals use gills to breathe.
Gills are simply layers of tissue adapted
specifically to gas exchange.
Respiratory organs : Respiratory organs BOOK LUNG – Some spiders, scorpions, and other arthropods still use primitive book lungs, adapted for land use, in their respiration. These are simply tissue with many wrinkles to increase their surface area.
Respiratory organs : Respiratory organs INVERTEBRATE TRACHEA –eg: many arthropods .
These are tubes which simply lead directly into their bodies through holes called spiracles, where their internal organs generally absorb their own air.
LUNG – The lung is made up of muscle tissues. the cells inside the lung collects the oxygen in the air and pass it into the blood stream and takes carbon dioxide out and of the blood stream.
Common characteristics : Common characteristics a structure that increases the surface area which is in contact with the oxygen-rich atmosphere.
The surface of this structure is very fine and delicate.
Are usually placed within the body for protection
there have to be passages that will take air to this area.
there is a mechanism for moving the air in and out of this area where the oxygen is absorbed.
Cellular respiration : Cellular respiration Where does cellular respiration take place?
IN THE CELL.
Which part of the cell?
BOTH IN THE CYTOPLASM AND IN MITOCHONDRIA.
What are the steps involved in respiration?
BREAKING DOWN OF GLUCOSE (GLYCOLYSIS)
BREAKING DOWN OF PYRUVIC ACID IN ORDER TO RELEASE ENERGY.
Breaking down of glucose : Breaking down of glucose Breaking down of glucose ( a 6 carbon molecule) into pyruvic acid ( a 3 carbon molecule) is called as glycolysis.
C6H12O6 + O2 C3H4O3
THIS HAPPENS IN THE CYTOPLASM OF THE CELL.
BREAKING DOWN OF PYRUVATE : BREAKING DOWN OF PYRUVATE Conversion of pyruvate during respiration depends on whether the organisms respire aerobically or anaerobically.
THIS HAPPENS IN THE MITOCHONDRIA OF THE CELL.
Types of respiration : Types of respiration
Aerobic respiration : Aerobic respiration It must be noted that the first step of respiration – glycolysis is common to both aerobic and anaerobic respiration. Thus, in anaerobic respiration also pyruvic acid is formed.
Pyruvic acid is converted into carbondioxide and water.
The overall reaction for aerobic respiration is
C6H12O6 +6O2 6CO2+6H2O + 38 ATP.
Aerobic respiration : Aerobic respiration This type of respiration is present in higher plants and animals including human beings.
General Equation:
C6H12O6 + 6O2 ---------------> 6CO2 + 6H2O + Energy.
Anaerobic respiration : Anaerobic respiration There are certain microbes that respire in the absence of free oxygen. This respiration is called anaerobic respiration. It is also called fermentation.
It takes place in yeast (fungi), bacteria such as E.coli, Clostridium tetani, etc.
Among animals, only certain cells are temporarily anaerobic (when they are short of oxygen) such as the muscle cells.
Anaerobic respiration:
Lactic acid fermentation
Alcohol fermentation
Alcoholic Fermentation : Alcoholic Fermentation It occurs in fungi like the yeast (a fungus)and in certain bacteria.
First step is glycolysis.
Pyruvate is converted into ethanol, CO2 and energy.
It can be represented as follows: Glucose pyruvic acid ethanol + 2CO2 + 2ATP
This process also takes place in higher plants for a very short while and only when free oxygen is not available. For example, germinating seeds respire anaerobically.
Lactic Acid Fermentation : Lactic Acid Fermentation Here the pyruvic acid is converted intolactic acid.
Glucose pyruvic acid lactic acid + 2ATP .
During this process, no carbon dioxide is released. It is because of the accumulation of lactic acid that there is fatigue and cramps in the muscles after prolonged exercises.
Importance of Anaerobic RespirationBack to Top : Importance of Anaerobic RespirationBack to Top Anaerobic respiration releases less energy, it meets the requirements of the microbes growing in anaerobic conditions.
Fermentation is a commercially important process.
It is used in the following processes: Manufacture of alcohol
Curing of tea leaves, tobacco, etc.
Formation of curd from milk
Manufacture of vinegar, an industrially important compound. Importance of Anaerobic Respiration
Aerobic vs Anaerobic : Aerobic vs Anaerobic Anaerobic respiration is far less efficient than the aerobic respiration.
The anaerobic respiration releases very few ATP molecules (2 ATP) whereas the aerobic respiration releases a lot of ATP molecules (38 ATP).
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