carbohydrates

Question 1

what is a monosaccharide

Answer 1

the monomers from which larger carbohydrates are made
eg. glucose, fructose, galactose

Question 2

what are the disaccharides and what bond

Answer 2

maltose = glucose + glucose
sucrose = glucose + fructose
lactose = glucose + galactose

Question 3

what are the isomers of glucose

Answer 3

alpha glucose and beta glucose
(draw)

Question 4

what is the function and structure of glycogen and how do they relate

Answer 4

function - energy store in animal cells
structure - polysaccharide of alpha glucose
relate
- branched so can be rapidly hydrolysed to release glucose for respiration
- large molecule so cant leave cell
- insoluble in water so water potential of cell not afffected

Question 5

what is the function and structure of starch and how do they relate

Answer 5

function - energy store in plant cells
structure - polysaccharide of alpha glucose
amylose is unbranched
amylopectin is branched
relate
- helical so compact for storage
- large so cant leave cell
- insoluble in water so water potential of cell not affected

Question 6

what is the function of cellulose and how does its structure and function relate

Answer 6

function - provides strength and structural support to plant cell walls
structure - beta glucose
relate
- every other beta glucose is inverted so long straight unbranched chain
- many hydrogen bonds link parallel to strands to form micro firbrils
- h bonds are strong in high numbers

Question 7

what is the biochemical test for a reducing sugar

Answer 7

benedicts
add benedicts reagent
heat in water bath
positve = green to red

Question 8

what is the biochemical test for non reducing sugars

Answer 8

benedicts
add dilute HCl
neutralise with alkali
add benedicts reagent
reheat
positive = green to red

Question 9

what is the biochemical test for starch

Answer 9

iodine
add iodine and shake
positive = blue/black