Intro to Carbohydrates Flashcards
Emily
Monosaccharide structure
- 3-6 C atoms
- Carbonyl group & hydroxyl group
Fischer projection
Most oxidised group at top (carbonyl)
L & D notations
Side of OH on chiral furthest from carbonyl:
- Left = L
- Right = D
Naturally occurring carbohydrate isomer
D isomer
Aldoses
1 aldehyde group w hydroxyls
Ketoses
1 ketone group w hydroxyls
D-glucose
Aldohexose
Epimers
- what
- example
- Differ at chiral centre (not one which determines L or D)
- D-glucose vs D-galactose (C4 = difference)
Cylic structures
- when occur
- RHS goes…
- 5/6 C, often in solution
- RHS goes BELOW
Anomers
- what
- example
- cyclic monosaccharides differing around C1/2
- glucose –> alpha vs beta
Starch
- function
- 2 types
- Plant energy storage
- Amylose, amylopectin
Amylose vs amylopectin
- Unbranched, only a-1-4
vs - Branched, a-1,4 & a-1,6
Cellulose
b-1,4 linkages
Glucose = in inverted orientation (e.g. C6 = above, then below)
Cellulose in mammals
Passes through as ‘roughage’
Glycogen
- what
- function
- structure
- storage
- Most common polysaccharide in animals
- Storage form of glucose
- Branched –> glycosidic links a-1,4 and a-1,6
- In liver & muscles
Reducing sugar
- ion change
- colour change
- reaction in monosaccharides
- Cu2+ reduced to Cu+
- Blue –> orange
- Carbonyl group donates electrons (is oxidised)
Spectrophotometer measures concentration using…
- Absorbance
- Compare w absorbance of different known concentrations
Measuring glucose conc over short time (example)
Urine dip-stick
Galactosemia
- caused by
- effects
- solution
- Lack enzyme for galactose –> glucose SO accumulate galactose intermediates
- Toxic effects in liver, brain etc (as energy dependent)
- Avoid lactose
Measuring glucose conc over long time (example)
Glycation
How does glycation work x3
- glucose enters rbcs
- binds w haemoglobin
- more glucose = more binding
Why is glycation long-term
Rbcs have life-span of ~3 months
Lactose
- which monosaccharides
- where is link
- b-D-galatose + a/b-D-glucose
- b-1,4 glycosidic (b from galactose)
Lactose intolerance
- why
- what happens
- symptoms
- causes
- lack of lactase
- lactose –> colon –> fermented by bacteria
- stomach cramps, bloating etc
- inherited OR developed
