Posts Tagged ‘Energy’

Nutrient Groups – Carbohydrates

Posted: December 10, 2012 in National Certificate
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There are six basic nutrient groups.  Three of them provide energy and three are non-energy nutrients.

Energy Nutrients

  • Carbohydrates (provide energy and fibre)
  • Fats (provide slow release energy, improves taste, stores vitamins A, D, E & K)
  • Proteins (provides energy and used for growth and healing)

Non-Energy Nutrients

  • Vitamins (required for the body’s chemical reactions for metabolism)
  • Minerals (required for the body’s functions)
  • Water (essential for all the body’s cells, makes up 60-70% of the body’s weight)


There are three forms of carbohydrates:
Sugars – Provide energy quickly, they are relatively simple molecules and are absorbed and used efficiently by the body – glucose is the most important simple sugar.

Starches – Provide energy more slowly as they are longer chains which must first be broken down into simple sugars before they can be used.

Domestic Rabbit

Fibre – Fibre is an indigestible form of carbohydrate in cats and dogs.  Rabbits, Horses and Ruminants (like cattle and sheep) can break down fibre to use as energy.  Cats and dogs cannot break down fibre and so it can be used to bulk out the diet and control an animal’s weight by  making the animal feel full without providing lots of energy.

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Powerhouse

Posted: September 19, 2012 in Higher National Certificate
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The Mitochondria are structures or ‘Organelles’ found inside cells.
They are termed the ‘Powerhouse’ of the cell because they generate energy in order for the cell to be able to carry out its functions.
The process of energy generation is called ‘Cellular Respiration’ and involves a chemical reaction known as ‘Oxidative Phosphorylation’.  Oxidative Phosphorylation occurs on the surface of the inner membrane of the mitochondrion.
Cells which use a lot of energy, e.g. Muscle Cells have a lot more mitochondria than cells which do not require a lot of energy, e.g. Fat Cells.

The Structure of Mitochondria
The mitochondrion has two membranes, an inner membrane and an outer membrane.
The outer membrane is smooth but the inner membrane is folded – this means that there is more space (a larger surface area) for Oxidative Phosphorylation to take place.
These folds are known as ‘cristae‘.

Parts of the Mitcohondrion

Also inside the mitochondria are ribosomes (another organelle also found around the cell itself) and a ring of Mitochondrial DNA.

For interest: the mitochondrial DNA shows many similarities to bacterial DNA and differs from the DNA found in the cell’s own nucleus.  It is thought that, in evolutionary terms, mitochondria may have started out as independent creatures which set up a mutually beneficial relationship with cells of more complex organisms such as animals and plants.