Archive for the ‘Carbohydrates’ Category

Beta Oxidation

Hey guys,
So the project for Biochemistry this semester was a video project. My group decided to based our video on Beta oxidation, giving the necessary steps and explaining them in detail. Please give us your support by looking at the video and commenting if you so desire.

Many Thanks.

Brandon.

Anomers.

An Anomer of a saccharide only differs in it’s structure at the anomeric carbon. Anomeric carbon being the functional group of the carbohydrate, which is usually the carboxyl group attached to it.

For example, anomers of glucose are alpha-glucose and beta-glucose.

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Note, the change in position of the hydroxyl group (-OH) on the anomeric carbon( C1).

Epimers.

Epimeres, differ at only one chiral center, not the anomeric carbon.

For example, epimers of glucose.

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Note: Glucose has 5 chiral centers. Notice the change on the the second carbon, the hydroxyl switches places with the hydrogen to give a new structure, thus new properties.

A chiral molecule is one that is not super-imposable on itself, meaning it is not identical to its mirror image. Two mirror images of a chiral molecules are called enantiomers, which are termed either left or right, or in biochemistry, L or D.

glucose

An aldose consist of one aldehyde (CH=O) group per monosaccharide.

For example Glucose.

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A ketose sugar is one containing a ketone group per molecule.

For example, Fructose.

fructose-Ketose

 

 

As shown, aldoses differ from ketoses, with the carboxyl group at the end of the chain, rather than the middle.

 

 

Monosaccharides.

These are the simplest types of carbohydrates. They are all white, crystalline solids and readily reduces other chemicals, which makes them reducing sugars. Different arrangements of the atoms give these molecules different shapes and properties.

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.Disaccharides.

These sugars are formed when two monosaccharides react together via a condensation reaction.

eg. glucose + glucose →condensation→ maltose + water

The bond form is known as a glycosidic bond. The most common disaccharides are:

  • Maltose: α-glucose + α-glucose
  • Lactose: α-glucose + galactose
  • Sucrose: α-glucose + fructose.

Polysaccharides.

These are long, complex chains made up of many monosaccharides. They are insoluble in water and are not sweet or considered sugars. The most common are starch, glycogen, and cellulose.

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Well, as you probably guessed it, its time for carbohydrates.

Carbohydrates are made up of carbon, hydrogen and oxygen, and have a general composition of C(H2O)n. The major role of carbohydrates is to provide energy for cells. They participate in many reactions required by the body.

Significance of carbohydrates:

  1. Energy Source
  2. Storage
  3. Structure
  4. Precursor molecules

Carbohydrates as an energy source.

Animals break down carbohydrates into Carbon Dioxide and water. Monosaccharides ,eg. glucose, and disaccharides break down easily to provide rapid supplies of energy. Polysaccharides, on the other hand, go through a longer process but eventually gives the same products.

Carbohydrates as storage

Carbohydrates in the form of polysaccharides are used for storage. eg Starch in plants.

.ImagePicture of an Iodine experiment done to show presence of starch in leaves.

Carbohydrates for structure.

Cellulose ( Beta-glucose), is fibrous and strong. It is the major component in plant cell walls. Chitin is similar to cellulose, with an acetyl amine group replacing one hydroxyl group, and is found in the exoskeleton of many insects.

Carbohydrates as precursor molecules

Carbohydrates are the basic requirements for the creation of most biomolecules. eg ribose in DNA and RNA.