The document discusses respiration, which is the process by which organisms obtain energy from food through the breakdown of glucose. There are three main types of respiration: aerobic respiration, which uses oxygen to fully break down glucose; anaerobic respiration, which breaks down glucose without oxygen; and lactic acid fermentation, an alternative pathway used by muscle cells during heavy exertion. The stages of respiration include glycolysis, which breaks down glucose in the cytoplasm, and subsequent pathways that further break down pyruvic acid, depending on oxygen availability. The document also describes the respiratory organs that different organisms use to intake oxygen and remove carbon dioxide, including lungs in humans and other terrestrial animals.

1. RESPIRATION
Introduction
The food materials taken in during nutrition is used in the
cell to provide energy for various life process.
The process of release of energy through enzymatically
controlled biological oxidation of glucose is called
RESPIRATION
It is an exothermic & catabolic process in which
substrate glucose is oxidized to release energy in the cell
(Mitochondria)
The energy released is stored temporarily as ATP
The by product Carbon- di -oxide play an active role in
maintaining carbon- di -oxide balance in nature

2. Types of Respiration
• Diverse organism respire in different way
• Most of the organism use oxygen to breakdown glucose completely
into carbon-di-oxide, watar & energy. This is called aerobic
Respiration
• C6H12O6 + 6O2----------6CO2 + 6H2O + Energy (686Kcal = 38 ATP)
• Some organism use other pathway that do not involve
oxygen. Eg Yeast, Bacteria (Micro-organism)
• The breakdown of glucose into CO2 & alcohol(Ethanol) in
absence of (without) oxygen is called Anaerobic respiration
• C6H12O6 ------------------2C2H5OH + 2CO2+Energy (56Kcal)
• Sometimes when there is lack of oxygen in our muscle cells
another pathway called lactic acid fermentation occurs.
• Glucose is oxidized partially into lactic acid.

3. Respiration

4. Glycolysis
• Glycolysis is the common respiratory pathway in
all types of respiration. It occurs in cytoplasm.
Hence called cytoplasmic respiration.
• The cellular breakdown of glucose through a
series of glycolytic enzymes to Pyruvic Acid acid is
called GLYCOLYSIS
• During glycolysis one mole of glucose is broken
down into two mole of pyruvic acid & there is a
net release of 2 ATP
• Glucose + 2ATP --------------2 Pyruvic Acid + 4ATP
• C6H12O6 +2ATP----------------2 CH3COCOOH + 4ATP

5. Aerobic Respiration
• Further oxidation of Pyruvic Acid depends on availability or non availability of oxygen in different
organism under different pathway
• Aerobic Respiration
• Occurs in mitochondria
• Pyruvic acid is completely oxidized into CO2,H2O & release energy in presence of oxygen with the
help of respiratory enzymes
• Overall 38 ATP is released from aerobic respiration
• Glucose--------Pyruvic Acid--------CO2 + H2O +38ATP
• Anaerobic Respiration (Fermentation)
• Pyruvic acid is partially oxidized into Ethanol (C2H5OH), CO2 & release less energy in absence of
oxygen with the help of enzyme
• It may occur in the cytoplasm (intracellular) or outside cell(extracellular with the help of enzymes
secreted by the cell (FERMENTATION)eg yeast
• Only 8 ATP is released
• Glucose----2Pyruvic Acid ----2Ethanol +2Co2 +E (8ATP)
• Lactic Acid Fermentation
• It occurs in muscle cells when there is scarcity of oxygen & more demand of energy
• Ie it is an alternative pathway to fulfill instant demand of energy when normal aerobic respiration
fails to satisfy demand of energy during heavy duty,/exercise etc.
• It is a less efficient pathway of respiration releasing only 2 ATP
• The lactic acid accumulated in the muscle cause muscle cramp and later thelactic acid enters into
aerobic cycle & get consumed.
• Glucose----Pyruvic Acid ------Lactic Acid +2ATP

6. Respiratory organ
• Animals have evolve different organs for the uptake of oxygen
from environment & for getting rid of co2 from the body
• Unicellular organism like Amoeba, Euglena, Paramecium
etcrespire through body surface by the process of simple
diffusion.
• Insects respire through tracheal systemEarthworm respire
through skin
• Aquatic animals (fish) respire through gills. Since the amount
of dissolve oxygen in water is lesser with respect to air, the
rate of breathing is faster.

7. Human respiratory system
• Terrestrial organism use the oxygen present in
the atmosphere for respiration.
• The oxygen is absorbed different organs in
different animals
• The respiratory organs which is in direct
contact with oxygen rich atmosphere have
very fine ,delicate & highly vascular surface
with increased surface area called LUNG
• It is placed within body for its protection

8. The Lung
• Human respiratory system consist of Nostril, Nasopharyns, Larynx,
Trachea, Bronchi, Lung, Pleura, Diphram, Intercostal muscle.
• Nostrils- the gateway of respiratory system, are two nasal opening. The
Nasal cavity have hairs to filter dust & secret mucus to absorb fine dust
present in air.
• The Nasopharynx is the junction between nasal cavity & the larynx. It is
guarded by epiglottis which close the passage of air while swallowing.
• The Larynx (Adam’apple =voice box) contains two ligamentous fold calld
vocal cord. Air expelled between the vocal cord vibrate them producing
sound
• Trachea or wind pipe is a non-collapsable tube extending from larynx to
lung. It has cartilageneous ring.
• The Lung – There are two spongy elastic hollow organ formed of
bronchioles& alveoli. The right lung has three lobes & left lung has two
lobes.
• Trachea----Bronchi-----------Bronchioles------------------Alveoli

9. Structure of lung