Carbohydrrates

Question 1

What are monosaccharides in carbohydrates and what are their functions

Answer 1

Ch20
Determined by number of carbon the have , e.g triose sugar have 3 carbons
Two isomers a and b glucose
Source of energy in respiration ch cc bonds break to release energy transferred to atp
Building blocks for larger molecules e.g glucose
Intermediate reaction e.g triose and intermediates in reaction of photosynthesis and respiration
Constituent of nucleotides e.g deoxyribose

Question 2

Dissacharides

Answer 2

Two monosaccharides bonded together with formation of glycosidic bond 
Between c1 and c4 glycosidic bond 
Maltose - glucose and glucose 
Sucrose- fructose and glucose 
Lactose - galactose and glucose

Question 3

Test for carbohydrates

Answer 3

Benedicts rescuing sugars solution heated to maximum of 70 if reducing sugar present turns from blue to brick red

Non reducing sugars give negative result remains blue e.g sucrose only broken down to its constituent monosaccharides e.g heating with hcl then added and heated as before if red non reducing sugar was present
To get an actual concentration of sugar present is biosensor

Question 4

Polysaccharide. Use

Answer 4

Units of monosaccharides linked together by glysocidic bonds
Starch - insoluble no osmotic effect, cannot diffuse out of cell, compact molecule and can be stored in small place, carries a lot of energy in ch cc bonds ( Brocken down releases energy which is transferred to atp)

Question 5

Starch

Answer 5

Amylose - u branched molecule with 1-4 glysocidic bonds repeated forming chains and coils into helix

Amylopectin - chains of monomers joined with 1-4 glysocidic bonds and 1-6 glysocidic bonds cross linked

Question 6

Testing for starch

Answer 6

Iodine solution reacts with starch colour change from Orange brown to blue black
Qualities test and actual concentration cannot be determined depth of blue black colour gives an indication of relative concentration

Question 7

Glycogen

Answer 7

Main storage production animals
Similar to amylopectin 1-4 with cross links of 1-6 bonds difference is that have shorter 1-4 links and more branched than amylopectin

Question 8

Cellulose

Answer 8

Present in cell wall of plants
Consist of many long parallel chains of b glucose units glucose monomers joined by b1-4 no b link rates 180 degrees forming adjacent parallel chains and contributes to cell walk structurabilty cross links form micro fibrils held in bundles called fibres laminated structure

Question 9

Chitin

Answer 9

Found in exoskeleton o. Insects and in fungal cell wall it resembles cellulose
Long chains of b1-4 chains no amino acid added strong waterproof and lightweight , monomers rotated 180 degrees relation to neighbours and long parallel chains linked with cross links by hydrogen bonds forming micro fibrils