Student
These rodents are fairly widespread in dry areas of North and central America. They are examples of mammals which are specialised to live in a rather inhospitable environment.
It is worth pointing out certain facts about their lifestyle and biology.
The animals' diet is principally seeds, gathered at night and stored in underground burrows. They have large cheek pouches like hamsters for temporarily storing this material during their brief forays to the surface at night time when the air is cooler and more humid than in the heat of the day.
Their food is fairly dry and they do not take in liquid water by drinking.
Like most animals, they produce water due to the oxidation of foods used in respiration. This "metabolic water" is the product of aerobic respiration - the final stage of oxidative phosphorylation being the reduction of oxygen using hydrogen ions and electrons.
Lipids are especially important in this respect because on oxidation they produce more water than carbohydrates and proteins.
There is a great difference between the environment beneath ground and above ground.
The nasal passages within the kangaroo rat's skull have a large surface area and the turbinate bone is well developed.
It is said that whilst underground in their cool humid burrows (where they spend the majority of their time), kangaroo rats retain as much water as possible by effectively recycling water which would otherwise be lost in their breath.
Air with a high water vapour content leaves the lungs - the unavoidable consequence of exposing a relatively large surface area for the absorption of oxygen. Therefore air which is exhaled has a very high relative humidity - close to 100 per cent saturation, and it is also at core body temperature - 38°C.
If the temperature of the kangaroo rat's nasal passage is any cooler than 38°C due to the cooler external environment, then water will condense before leaving the animal. The liquid water can then be
It is worth pointing out certain facts about their lifestyle and biology.
The animals' diet is principally seeds, gathered at night and stored in underground burrows. They have large cheek pouches like hamsters for temporarily storing this material during their brief forays to the surface at night time when the air is cooler and more humid than in the heat of the day.
Their food is fairly dry and they do not take in liquid water by drinking.
Like most animals, they produce water due to the oxidation of foods used in respiration. This "metabolic water" is the product of aerobic respiration - the final stage of oxidative phosphorylation being the reduction of oxygen using hydrogen ions and electrons.
Lipids are especially important in this respect because on oxidation they produce more water than carbohydrates and proteins.
There is a great difference between the environment beneath ground and above ground.
The nasal passages within the kangaroo rat's skull have a large surface area and the turbinate bone is well developed.
It is said that whilst underground in their cool humid burrows (where they spend the majority of their time), kangaroo rats retain as much water as possible by effectively recycling water which would otherwise be lost in their breath.
Air with a high water vapour content leaves the lungs - the unavoidable consequence of exposing a relatively large surface area for the absorption of oxygen. Therefore air which is exhaled has a very high relative humidity - close to 100 per cent saturation, and it is also at core body temperature - 38°C.
If the temperature of the kangaroo rat's nasal passage is any cooler than 38°C due to the cooler external environment, then water will condense before leaving the animal. The liquid water can then be