Carbohydrates Flashcards
what is the general formula for carbohydrates?
CH20
what 2 functions do monosaccharides have?
energy for respiration
forms larger molecules
what would you call a monosaccharide with 5 carbon atoms? 3 carbon atoms? 6 carbon atoms?
pentose
triose
hexose
what is the most common hexose sugar? what is it’s formula?
a-glucose C6H1206
what do carbohydrates make up?
biological molecules - any living thing
what is an isomer?
has the same chemical formula but a different structure
what reaction changes a monosaccharide into a disaccharide? what bond does this form?
condensation - glycosidic
what is a disaccharide?
2 sugars bonded together
what is a polysaccharide?
3 sugars or more bonded together
EG starch
what reaction changes a polysaccharide into a disaccharide? what needs to be present for this to happen?
hydrolysis reaction
water
what makes up sucrose?
fructose and a-glucose
what makes up maltose?
a-glucose + a-glucose
what makes up lactose?
a-glucose + galactose
how is beta glucose shown?
0H shown on the top and H on the bottom
what is a common polysaccharide?
starch
what does insoluble?
cannot be dissolved
what 2 things makes up starch?
amylose and amylopectin
how is amylose formed and describe its structure.
by a condensation reaction
coiled springs with 1,4 links of 3 or more a-glucose
what is amylopectin structure like?
a-glucose but a branched structure with 1,6 links
how do you test for starch?
what is a positive result?
negative result?
add iodine to solution
blue/black = positive
yellow / orange = negative
why is the polysaccharide glycogen good for respiration?
because it stores glucose and it’s so compact
what is glycogen made up of?
1,4 links and 1,6 links
what does the polysaccharide chitin make up?
fungal walls and exoskeletons of insects
what does the polysaccharide cellulose make up? how?
plant walls - cellulose chains, hydrogen bonds, microfibres, fibres
