Reflection Post: Part four (4)

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Ok guys… So on to week (2 and 3) of this semester.

Basic knowledge on CARBOHYDRATES!

        A carbohydrate is an organic compound with the general formula C”m”(H 2 O)”n”. They all consist only of carbon, hydrogen and oxygen, the last two elements in a 2:1 atom ratio, respectively. Carbohydrates can be viewed as hydrates of carbon, hence their name. There can also be classified as an aldehyde or a ketone that has additional hydroxyl groups. Carbohydrates or saccharides are the most abundant class of biomolecules. Carbohydrates are used to store energy, though they serve other important functions as well. Some of these functions include:

  • Fuel for cellular metabolism (Monosaccharides)
  • In numerous biosynthesis reactions.
  • They form structural elements, such as chitin in animals and cellulose in plants.
  • Precursor molecules

Metabolism of carbohydrates:

  • Glycolysis
  • Pentose phosphate pathway
  • Glycogen synthesis and catabolism
  • Gluconeogensis

Small carbohydrates, for example glucose, are comprised of one or two sugar units. These molecules are sometimes called “simple sugars” because they are small (only one or two units; monosaccharides and disaccharides), and are rapidly digested, immediately supplying energy to the body. In comparison, larger carbohydrate molecules, which include starches, are composed of at least twenty or more monosaccharides linked together. Another term commonly used to describe carbohydrates is oligosaccharides, a type of carbohydrate molecule that is in between polysaccharides and monosaccharides in size, and features three to twenty monosaccharides bonded together. Other large carbohydrates, called polysaccharides may contain up to several hundred monosaccharides linked together in different ways.

 
 
Three characteristics are used to classify monosaccharides:
  • number of carbon atoms in the molecule;
  • location of the carbonyl group;
  • the chirality of the carbohydrate
    • Aldose – monosaccharide in which the carbonyl group is an aldehyde
    • Ketone – monosaccharide in which the carbonyl group is a ketone
    • Triose – monosaccharide with 3 carbon atoms
    • Tetrose – monosaccharide with 4 carbon atoms
    • Pentose – monosaccharide with 5 carbon atoms
    • Hexose – monosaccharide with 6 carbon atoms
    • aldopentose – 5-carbon aldehyde (e.g., ribose)
    • ketohexose – 6-carbon hexose (e.g., fructose)

Depending on the orientation of the asymmetric carbon located furthest from the carbonyl group, a monosaccharide is either ‘D’ or ‘L’. In a ‘D’ sugar, the hydroxyl group is on the right the molecule when written, however, if the hydroxyl group is on the left of the molecule, then it is an ‘L’ sugar. The ‘D’ representation is more commonly used as compared to the ‘L’ representation with is rear in nature.

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What you need to remember about carbs!

  • Eat the green stuff!
  • Reduce the quantity of carbohydrates to lose weight.
  • Avoid processed sugars to keep healthy.
  • They should represent 40-60% of your diet.

What happens if I eat too much of this?

  • You guessed it! You gain weight.
  • Your blood glucose levels spike, and after a while they fall back and you feel depleted of energy.
  • Diabetes, Hearts Diseases and other conditions linked to obesity.

But what if I avoid them?

  • You’ll lose weight. You won’t have enough energy to carry out your daily task so your body will burn stored fat for fuel.
  • If you avoid them for more than 3-4 days, you’ll go into a state of Ketosis. This is what the Atkins diet is based on. The body starts producing glucose out of fat and protein and stops asking you to eat some sugar. So, you’ll lose weight.
  • If you avoid them for too long, you’ll be depleted of all those vitamins and minerals that you get from fruit and vegetables. And you need those!

Good carbs vs Bad carbs

  • Good would be the fruit and vegetables. The greener they get, the healthier they are!
  • Bread and similar products are somewhere in the middle. They still give you a lot of benefits.
  • Bad carbohydrates are sweets and everything that contains refined sugar! Do your best to stay away from those!

 

Information sourced from:

1) http://www.hsph.harvard.edu/nutritionsource/carbohydrates/

2) http://www.nerdgraph.com/good-carbs-vs-bad-carbs/

3) http://www.google.tt/search?q=good+carbs+vs+bad+carbs&hl=en&source=lnms&tbm=isch&sa=X&ei=iwkkUYX_D4Lo8QTP6oDwDA&sqi=2&ved=0CAcQ_AUoAQ&biw=1366

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