L1: Monosaccharides

Question 1

What are cabohydrates?

Answer 1

• they are organic compounds that are formed mainly of CHO but not always where is the ratio of hydrogen to oxygen is 2:1 like water they are called carbohydrates.
• they are defined as polyhydroxy aldehydes and polyhydroxy ketones or any other compounds yielding them on Hydrolsis.

Question 2

What is the function of carbohydrates?

Answer 2

• they are the main source of energy
• they enter in the structure of sugar-phosphate backbone
• they enter in the structure of cell membrane
• they enter in the structure of glycolipids and glycoproteins.
• they play a role in cell recognition as well

Question 3

What are monosaccharides classified according to?

Answer 3

They are classified according to the number of carbon atoms and active carbonyl group whether it is aldehyde or Ketone.

Question 4

Triose

Answer 4

Glycerldehyde

Dihydroxy acetone

Question 5

Tetrose

Answer 5

Erythrose

Erthyroluse

Question 6

Pentose

Answer 6

Arabinose
Ribose
Xylose

Xylulose
Ribulose

Question 7

Hexose

Answer 7

Glucose
Galactose
Mannose

Fructose

Question 8

Heptose

Answer 8

——-

Sedoheptulose

Question 9

What is the importance of glucose?

Answer 9

• It is a major source of energy for tissues and cells.
• some tissues and cells like brain and erthrocytes depends mainly on glucose as it cant oxidize on the any other alternatives for fuel.
• therefore the body keeps a fairly constant amount in the blood ranging between 70 to 110 mg/dl.
• all the ingested sugar is absorbed in the form of glucose.
• It is a changed into other forms like galactose,ribose,fructose and glygogen in other organs like the liver.

Question 10

Galactose

Answer 10

• It is formed in mammary glands.
• It helps in the formation of lactose.
• It is a constituent Of glycolipids and glycoproteins.

Question 11

Mannose

Answer 11

It is a constituent of glycoproteins and Amino sugar acids.

Question 12

Fructose (levulose) (fruit sugar)

Answer 12

• It is found in the seminal fluid as to provide energy for the sperms.
• It is also a constituent in the formation of Inulin which is a polysaccharides and sucrose which is a disaccharide.

Question 13

Ribose

Answer 13

• It enters in the structure of sugar-phosphate backbone.
• It enters in the formation of co enzymes like NAD.
• Deoxy ribose enters in the formtion of DNA.
• Ribose enters in the formation of RNA - ATP -NAD.

Question 14

What are sugar derivatives?

Answer 14

• Sugar acids
• Deoxy sugars
• Amino sugar
• Amino sugar acids
• Glycosides

Question 15

What are sugar acids?

Answer 15

-They are the yield of the oxidation of carbon atoms to carboxylic groups.

First——> aldonic acids
Last——> uronic acids
Both——> aldaric acids “glucaric is sacharic acid”

And ascorbic acid “vitamen C” which is six carbon sugar acid and it is soluble in water and optically active and must be supplied in diet.

By glucose oxidase enzymes and this technique is used in test stripes to test the amount of sugar in blood and urine

Question 16

what are deoxy sugars?

Answer 16

• Monosaccharides with one oxygen missed (one OH group replaced by H).
• 2-Deoxy-D-ribose is a constituent of DNA.

Question 17

Give examples for amino sugars

Answer 17

• glucosamine
• Galactoseamine

The hydroxyl group is replaced by an amino group at the C-2 position, And they are found in glycoseamineglycans (GAGS)
And glycoproteins

Question 18

What are amino sugar acids?

Answer 18

-They are the yield of condensation reaction between acids and amino sugars like neuraminic acid which is found in neural tissues and is formed duet l the reaction between mannosamine and pyruvic acid.

Question 19

What are glycosides?

Answer 19

They are compounds that are connected by glycosidic bonds and there are two types of glycosidic bonds O and N.

Question 20

What are O-Glycosides ?

Answer 20

-they are compounds that contain O-glycosidic bond between and it arises by the attachment of the hydroxyl group on the sugar with the hydroxyl group on the other compound whether it is a CHO or not by removal of water.

From the examples:glycoproteins (Hydroxy amino acids) ,Glycolipids ,Disaccharides ,Poly saccharides and oligosaccharides, Cardiac glycosides “galactose + steriod “(digitalis used for treating heart failure).

Question 21

What are N-Glycosides?

Answer 21

-They are compounds that contain N-Glycosidic bonds between them that arise from the attachment of the hydroxyl group of the sugar with the amino group of the other compound.

For example:- DNA and RNA nucleotides.

Question 22

Symptoms of diabetes

Answer 22

• Polyuria
• Polyphagia
• Polydipsia

Question 23

How are glycosides named?

Answer 23

-They are named according to the sugars they contain.

E.g: Glucosides, galactosides