Organic Biochem

What are Glycosides?

They are formed when a sugar molecule(glycone) binds via a glycosidic bond to a non-sugar molecule(aglycone).
Eg glycoproteins, glycolipids etc.

What is the main function of glucose in the body?

To provide energy for the body

What is the role of Carbohydrates in biological recognition?

Glycocalyx, comprises of glycoproteins and glycolipids serve as ID cards on cells to enable the body distinguish between self and non-self cells. It also helps group the blood into the various classes

How does dietary fibre help reduce blood cholesterol levels?

In the gut, soluble fibres bind to bile salts to speed up their egestion from the body. This increased removal of bile salts from the body tells the body there is a shortage of bile hence more cholesterol is taken from circulation to produce more bile salts. This thus leads to the overall reduction in cholesterol in general circulation

What is Ketosis?

Is a situation where the body uses fats as its main energy source instead of glucose. This often happens during periods of starvation or low-carb diets

What is the storage form of glucose and where are they usually stored?

It is GLYCOGEN and is stored mainly in the Liver and Muscles

What are the classification of monosaccharides?

Trioses(3), Tetroses(4), Pentoses(5), Hexoses(6), and Heptoses(7)

What is the difference between Aldoses and Ketoses

Although both are sugars, Aldoses have the carbonyl group outside the main chain whiles Ketoses have it inside the chain---in the crystalline form that is

What type of sugar is Dihydroxyacetone?

A Ketose

What type of sugar is glyceraldehyde( glycerose)

Aldose(triose)

What type of sugar is Erythrose

An Aldose(tetrose)

What type of sugar is Erythrulose?

A Ketose(tetrose)

What type of sugar is Ribulose?

An Aldose

What type of sugar is Ribose?

Aldose

What type of sugar is Sedoheptulose?

A Ketose

What is Pentosuria?

The presence of L-Xylulose in urine due to a genetic mutation. Although it is harmless, it can create flase positive ls in urine test for glucose

What are Enantiomers?

They are stereoisomers that are mirror images of each other. Eg D-threose and L-Threose

What are Diastereomers?

Stereoisomers that are not mirror images of each other. Eg. D-Threose and D-Erythrose

What are Anomers?

Stereoisomers that differ with that configuration around and anomeric carbon. Eg alpha-glucose and beta-glucose

What are conformational isomers?

Stereoisomers with different 3D conformation in space. Eg chair form and boat form of glucose

What are enatiomers?

Stereoisomers that are non-superimposable mirror images of each other

What are epimers?

They are isomers that differ in configuration around a single carbon atom

Give examples of biologically relevant epimers and the Carbon atom responsible for their disparity.

Glucose and D-Mannose(C2)
Glucose and D-Galactose(C4)
Ribose and D-Xylulose (C3)

TAKE NOTE!!

When two molecules differ in configuration around more than one carbon atom they cease to be Epimers. They become DIASTEREOMERS

What are Hemiacetals and Hemiketoses?

They are basically fancy names for the anomeric carbon of Cyclic aldoses and ketoses respectively.

What do you know about Phosphate Esters?

They are formed when a Phosphoric acid (H3PO4) reacts with the -OH group of a molecule (in this case a monosaccharide) . Eg AMP, ATP and Nucleic acids

What are Lactones and how are they identified?

Lactones in simple terms are Cyclic Carboxylic esters. So basically eerh when you see cyclic monosaccharide with a carboxylic acid group at the anomeric carbon site that is a Lactone

How do you identify Uronic acids?

Similar to aldonic acids, the carboxylic acid group is attached to the last carbon of the Cyclic monosaccharide

"I am a chemical compound.
Lay men call me a ""sugar alcohol"" however if your feeling fancy🤷‍♂️ you can call me a ""polyol""
I am formed when a normal monosaccharide like glucose is reduced at the active site that is the carbonyl carbon.
This process causes my dear double bond oxygen with a measley Alcohol group😤
Not only does this inhumane reduction take away my double bond oxygen it also rids me of the ability to cyclisised i remain a straight chain
So who am I?"

An Alditol

Give two examples of amino sugars

Glucosamine and Galactosamine derived from glucose and galactose respectively

What are soluble and insoluble fibres and give examples of each

Soluble fibres; dissolves in water and is digestable. Eg Pectin and Mucilages
Insoluble fibres; do not dissolve in water. Eg cellulose and hemicellulose