RESPIRATION
RESPIRATION: It is a biochemical process of enzyme including oxidative breakdown of organic
compounds inside living cells releasing energy in the form of ATP
Food + O2 Oxidation CO2 + H2O+ Energy.
Breathing : The process by which organisms obtain oxygen from environment and release carbon
dioxide produced during oxidation of food to the outer environment is called as Breathing.
It is a part of respiration.
Difference between breathing and respiration.
Breathing Cellular Respiration
It is a physical phenomenon where exchange of It is a biochemical process where glucose is
oxygen and carbon dioxide takes place. oxidized to produce carbon dioxide and water.
Energy is not released. Energy is released.
Enzymes are not involved. A series of respiratory enzymes are involved to
bring about the oxidation.
It is extra cellular. It is intracellular.
Respiration Combustion
It is a biochemical process. It is a chemical process.
It takes place at normal temperature. It takes place at high temperature.
Respiration is a slow process completed in several Combustion is fast process in which the energy is
steps. Thus, the energy is also liberated in several liberated only in one step resulting in increase in
steps and remain stored in the form of ATP. temperature and production of fire.
A series of respiratory enzymes are involved. No enzymes are involved.
Types of Respiration:
Aerobic : When oxidation of food takes place in presence of oxygen. It is called as Aerobic
respiration.
Food In cytoplasm Glycolysis Pyruvic acid Kreb cycle in mitochondria 6CO2 + 6H2O + 38 ATP
O2
Anaerobic respiration: When oxidation of food material does not require oxygen or it occurs in
absence of oxygen, it is called as Anaerobic Respiration.
Aerobic respiration Anaerobic respiration
It occurs in all living cells of higher plants. It occurs in bacteria, certain fungi, germinating
seeds, fleshy fruits and muscle cells.
It requires oxygen Oxygen is not required
The end products are CO2 and H2O The end products are alcohol & CO2 or lactic
acid.
The oxidation of one molecules of glucose The number of ATP molecules produced is
produces 38 ATP molecules only 2 ATP.
All the reactions except the reactions of All the reactions take place in cytoplasm.
glycolysis take place inside mitochondria
Non toxic to higher organisms Toxic to higher organisms.
Organic compounds are completely oxidized Organic compounds are incompletely oxidized
and high amount of energy is released and very small amount of energy.
Step of respiration:
(i) External respiration: Exchange of gases between an organism and its environment.
(ii) Internal respiration: Exchange of gases between tissue cells and extracellular
environment.
(iii) Cellular respiration: Involves oxidation of food along with release of energy, inside cell.
RESPIRATION IN PLANTS
By young roots : Air occurs in soil interspaces. Root hairs as well as epiblema cells of
the young roots are in contact with them. They are also permeable to metabolic gases.
Oxygen of the soil air diffuses through root hair-epiblema cells and reaches all internal
cells of the young root. Carbon dioxide produced by root cells diffuses in the opposite
direction.
Lenticels: Present in old roots and stems, these are covered by protective layer of dead
cells known as bark.
Leaves and Young Stems : Leaves and young stems are ideally suited to quick exchange
of gases. The organs have a covering of nearly impermeable epidermis for reducing loss
of water. The epidermis of leaves bears a number of aerating pores called stomata.
RESPIRATION IN ANIMALS
Animals Type of Respiration
Amoeba (Protozoa) Diffusion : Exchange of gases takes place
through general body surface
Earthworm (Annelida) Cutaneous Respiration : Exchange of
gases occur through moist skin.
Fish (Pisces) Branchial Respiration : Exchange of gases
through gills.
Arachnids(scorpions & spiders) Book lungs.
Grasshopper (Arthropoda) Tracheal Respiration : Exchange of gases
through spiracles.
