carbohydrates

Question 1

general formula for carbohydrates

Answer 1

cx(h20)y

Question 2

types of carbohydrates

Answer 2

monosaccharide, disaccharide and trisacccharides

Question 3

example of monosaccharides

Answer 3

glucose, fructose and galactose

Question 4

example of disaccharides

Answer 4

maltose - glucose + glucose
sucrose - glucose + fructose
lactose - glucose + galactose

Question 5

polysaccharides

Answer 5

starch, glycogen and starch

Question 6

bio chemical test for presence of sugar

Answer 6

Benedicts test

Question 7

reducing sugars

Answer 7

called so because they are involved in a reducing reaction. includes all monosaccharides and some disaccharides as well.

Question 8

Test for reducing sugars

Answer 8

• add benedicts regaent to the solution and heat it in a water bath.
• if the color changes from clear blue to green, yellow, oranga and red brown due to the presence of insoluble copper oxide ppt, then it is positive.

Question 9

Test for non reducing sugars

Answer 9

• non reducing sugar has to be broken down into monosaccharides first
• heated with hcl and then is made alkaline using an alkaline solution with sodium hydroxide.
• then is treated with benedicts reagent and heated in a water bath.
• if there is presence of red color then its positive for presence of non reducing sugars.

Question 10

Test for starch

Answer 10

iodine test
iodine solution is orange brown in color. add a drop of iodine solution to the solid or liquid which is to be tested. if the color changes to blue black, then it indicates the presence of iodine.

Question 11

why is starch suited for its role

Answer 11

• helix shape making it compact so it can fit a large amount of glucose in a small space.
  branched structure increases the surface area for rapid hydrolysis back to glucose.
• insoluble in water - doesnt affect the water potential.
• it is a large molecule so it can not cross across the membrane.

Question 12

why is glycogen suited for its role

Answer 12

glycogen has 1-4 and 1-6 glycosidic bonds making it more branched which makes it more compact and suitable for storage.
- branching enables more free ends where glucose molecules can be added or removed.

Question 13

monosaccharides

Answer 13

monosaccharides are the monomers from which larger carbohydrates are made.

Question 14

what type of bond is formed when two monosaccharides are joined together?

Answer 14

glycosidic bond.

Question 15

polysaccharides definition

Answer 15

polysaccharides are formed by the combination of many glucose units.

Question 16

what is starch amde up of?

Answer 16

amylose and amylopectin.

Question 17

amylose?

Answer 17

amylose is a component of starch. amylose has unbranced helix chain with 1,4 glycosidic bond between alpha glucose moleules. the helix shape makes the molecules compact for storage.

Question 18

amylopectin?

Answer 18

amylopectin has 1,4 and 1,6 glycosidic bond between alpha glucose molecules providing a branced structure. the branches result in terminal glucose molecules which can be hydrolysed at the time of need during cellular respiration.

Question 19

where is glycogen found?

Answer 19

in the form of granules in the liver and muscle cells as they have a very high cellular rate of respiration.

Question 20

cellulose

Answer 20

polymer found in beta glucose.
b glucose is an inverse of alpha gluucose. so when it is inversed hydrogen bonds are formed.

Question 21

what bonds are present in starch, glycogen and cellulose?

Answer 21

starch - 1,4 and 1,6 glycosidic bonds.
glycogen - 1,4 and 1,6 glycosidic bonds.
cellulose - 1,4 glycosidic bonds.

Question 22

structure of cellulose

Answer 22

the polymers forms long straight chains.
the chains are held together in parallel chains by hydrogen bonds to form fibrils or micro fibrils.

Question 23

why is it suited for its function?

Answer 23

the hydrogen bonds between parallel chains of micro fibrils gives a tensile strength to withstand the pressure.
-insoluble - doesnot affect water potential.
-cellulose fibres and other molecules combine to form a matrix which provides an additional strength.