Types of respiration

 Respiration may be of two types, (a) Aerobic respiration and (b) Anaerobic respiration.

a)Aerobic respiration:

• Respiration which takes place in the presence of oxygen.

Glucose + Oxygen à Carbon dioxide + Water +Energy

b)Anaerobic respiration

• Some micro organisms like yeast and bacteria obtain energy from food in the absence of oxygen. So, the respiration which takes place in the absence of oxygen is called anaerobic Anaerobic respiration takes place in our skeletal muscle
• Bacteria and fungi can respire anaerobiaclly , which is useful in convertingsugar into alcohol.

Absence of oxygen

Glucose      àEthyl alcohol + Carbon dioxide + Energy.

Yeast is one-celled fungus and respires anaerobically to produce alcohol. Therefore, they are  used to make wine and beer.

Difference between breathing and respiration

Respiration in Man:

• The human respiratory system consists of nose, nasal cavity, trachea bronchi and lungs.
• The lungs are present in the chest cavity. We have muscles in out chest that make us breathe. Some are fixed to our ribs and make rib cage move in and out below the lungs is a strong ,flat sheet of muscle called diaphragm
• Our nose has two holes which are nostrils lead to nasal cavity which in turn  leads to trachea(wind pipe).The trachea divides into two branches called bronchi(singular-Bronchus)     
• Each bronchus enters the lungs and divides into small tubes called bronchioles. The end up in air sacs called alveoli(Singular-alveolus)
• The walls of alveoli are supplied with thin blood vessels called capillarieswhich carry blood in them Oxygen from the lungs enters the blood andcarbon dioxide from the blood reaches the lungs in the regions of alveoli.

How do we breathe?

• Breathing involves both inhalation and exhalation. It is a continuousprocess which goes on all the time and throughout the life span oforganisms.
• The number of times a man breathes in a minute is called the breathing rate.
• As we breathe in, the diaphragm moves down and ribs move up orexpands. This movement increases space in our chest cavity.
• Then the air rich in oxygen rushes into our lungs from outside through the route given below:
• As we breathe out, the diaphragm moves up to its original place and ribsmove down.” This reduces the size of the chest cavity and air is pushed out of the lungs through bronchi, trachea and nose.

Exchange of gases

• When oxygen-rich air goes to alveoli, oxygen is absorbed by the blood and combines with haemoglobin and is carried as oxy-haemoglobin to all cells of the body.
• In the cells, oxygen is used for oxidation of food to release energy alongwith water and carbon dioxide.
• This carbon dioxide is picked up by the blood and is transported to the lungs where it is exhaled
• Air pollution causes many respiratory
• Smoking can cause lung cancer
• Sound is the useful by product of respiratory system
• Like human beings ,animalsand plants also breathe and respire. The basic process of respiration  is same in all organisms
• In unicellular and smaller multicellular animals, all the cells take upoxygen from the surrounding air or water and give out carbondioxide by diffusion.

1. Amoeba, Paramecium

• Animals like earthworrn and leeches respire through the skin which is moist and slimy.
• Animals such as frogs -respire through their skin and lungs.
• Fishes have special organs called gills which are used to absorb the dissolved oxygen in water
• Animals like reptiles, birds and mammals have lungs for breathing.
• In animals such as insects, there are several small openings called spiracles on the lateral sides of their bodies.
• These spiracles lead to air tubes called trachea. Exchange of gases takes place through spiracles into trachea.

Homeostasis

• Horneostasis is the maintenance of a constant internal environment of thebody.
• It was first point out by the French physiologist Claude Bernard in 1857.
• Behavioural and physiological responses are two important regulatingmechanisms to maintain the stability of Homeostasis.

For example

• The control of blood glucose 1evel`is a good example of homeostasis andinvolves the secretion of atleast six hormones.

Cellular Respiration

• Respiration is the process by which chemical energy in organic molecule is released by oxidation.
• If it requires oxygen, it is described as aerobic respiration. If the process takes place in the absence of oxygen, it is described as anaerobic respiration.

Aerobic respiration

• It involves the utilization of free oxygen and results in complete oxidation to carbon-di-oxide and water

Anaerobic Respiration or Fermentation

• Here oxygenis not utilized for respiration.So,it is called anaerobic respiration. It is often referred to as fermentation

Metabolism

• The word metabolism has its root from the Greek work Metabloe which means change means change.
• The sum total of biochemical reactions involved in the release and  utilization of erergy exchange within the organism is termed as metabolism.
• Such a chemical reaction in the metabolic process can be divided into two categories.

1. Anabolism

The simple substances are obtained from the food are converted intocellular substance. This process is called Anabolism.

For example,

 Glucose -> Glycogen and other sugars

Amino acids -> Enzymes, hormones, proteins

Fatty acids -> Cholesterol and other steroids.

Catabolism

• Organic substances which are obtained from the food are broken down toproduce energy for the purpose of physiological functions of the cells.
• This-process is called as catabolism.
• Glucose à CO2, Water and heat
• Protein à amino acid
• Fats àGlycerol, fatty acid, etc.
• The repeated anabolism and catabolism in the metabolic processmaintains the homeostatic conditions of the body
• The metabolic process is responsible for movement growth, development,maintenance and repair of the cell,tissue and body
• Pelicans feed on fish,whichthey scoop up in the flexible pouch that lieunder their long beaks.