Carbohydrates 1 Flashcards
Why are Carbs a major energy source?
Theyre highly oxidisable beacuse of ‘high energy’ H atom-associated electrons.
How do carbohydrates have structural and protective functions?
In plants cellulose is critical to cell walls
In animals carbs form part of the ECM
How do carbs contribute to cell-cell communication?
They make up ABO blood groups.
How are disaccharides formed>
From monosaccharide momomers linked by a glycosidic bond. The OH group of one binds to the anomeric carbon of another.
What monomers make up Maltose?
2 Glc monomers
What monomers make up Lactose?
One Glc and one galactose
What monomers make up sucrose?
Glucose and Fructose (only one with no free anomeric carbon so no oxidation)
In what 4 waus are polysaccharides distinguished?
- reccuring monomer units
- Length of chains
- Types of bonds linking monosaccharides units
- AMount of branching
Define homo- and hetero- polysaccharides
homopolysaccharides have a single monomeric species
heteropolysaccharides have 2 or more
Name the 2 glucose polymers that make up starch an explain the difference:
Amylose and Amylopectin
amylopectin is branched
Why store glucose in starch as polymers?
for compactness and because they have many non-reducing ends allowin rapid synthesis and degradation
qWhy store glucose in glycogen as polymers?
Compactness
Rapid syntheis and degradation due to many non-reducing ends
Polymers form hydrated gels that are osmotically inactive stopping Glc from diffusing out of cells into the blood.
Name 4 effect sof carbs attached to proteins (glycoproteins)
- increased protein solubility
- influence protein conformation
- protect from degradation
- inter-cellular communication (cell signalling and recognition)
Where are glycoproteins found?
Mainly outer plasma membrane and ECM.
Also Blood and withing secretory system of cells (golgi body)
Occasionally as cytoplasmic or nuclear proteins.
What are glycosamioglycans? (GAGS)
“mucopolysaccharides”
Unbranched polymers of hexuronic acid and a repeating sugar
