Carbohydrates Flashcards
What are the monomers are carbohydrates?
Monosaccharides
When two of these monomers join what are they called?
Disaccharides
How many carbon molecules are in hexose sugars and name the three hexose sugar molecules.
There are 6 carbon molecules in hexose sugars.
The three main hexose sugars are glucose, galactose and fructose.
These hexose sugars are isomers.. Define the term isomer.
Isomers have the same molecular formula but a different structural formula.
Name the two pentose sugars and name what they form
Ribose sugar- RNA
Deoxyribose sugar- DNA
What are the two isomers of Glucose?
Alpha Glucose
Beta Glucose
What bonds form when two monosaccharides form and during what reactions does this occur?
Glycosidic bonds form between two monosaccharides and tis occurs within a condensation reaction.
What is the structure of a glycosidic bond? And what molecule is lost when this reaction happens?
C-O-C
H2O is lost.
Glucose + Glucose =
Glucose + Fructose=
Glucose + Galactose=
Maltose
Sucrose
Lactose
State what is meant by the term polysaccharide and give three examples of a polysaccharide
A polysaccharide are lots of monosaccharides joined via condensation reactions forming glycosidic bonds.
Starch, Glycogen and cellulose are all examples.
a-1,4 glycosidic bonds form what chains and why?
a-1,6 glycosidic bonds form what chains and why?
b-1,4 glycosidic bonds form what chains and why?
a-1,4: straight chains, OH Carbon 1 and OH Carbon 4
a-1,6: branched chains, OH Carbon 1 and OH Carbon 6
b-1,4: straight but alternating glucose, OH Carbon 1 and OH Carbon 4
What monosaccharides is starch made of and which bonds? And what structures do these then form?
Amylose and Amylopectin monosaccharides.
Amylose: a-1,4 glycosidic bonds- straight
Amylopectin: a-1,4 and 6 glycosidic bonds- branched structure
How is the structure of starch helpful for its function?
Helical and coiled so compact.
Branched meaning it can be rapidly hydrolysed by enzymes to release glucose for respiration.
Insoluble meaning it doesn’t affect water potential- prevents cells from bursting.
What bonds are glycogen made from? and what does this mean for its structure?
A-1,4 and 6 glycosidic bonds meaning its highly branched.
How does the structure of glycogen benefit its function?
Large and therefore cannot cross the cell membrane.
Insoluble so does not affect water potential.
Highly branched for rapid hydrolysis.
