Carbohydrates Flashcards
AQA
What is carbon’s unusual feature?
It readily forms bonds with other carbons
Name the four main elements
Oxygen Nitrogen Carbon Hydrogen
What is a monomer?
Small units from which larger units are made
Name 3 examples of monomers
Monosaccharides amino acids and nucleotides
What is a condensation reaction?
Joins 2 molecules together with the formation of a chemical bond and involves the elimination of a water molecule
What is a hydrolysis reaction?
Breaks a chemical bond between 2 molecules and involves the use of a water molecule
What is the monomer that makes up carbohydrates?
monosaccharides
Name 3 common monosaccharides ?
Glucose
Fructose
Galactose
Name the bond formed between two monosaccharides?
Glycosidic Bond
Monosaccharide + Monosaccharide =
Disaccharide
glucose + glucose =
maltose ( plus water !!)
glucose + fructose
sucrose ( plus water !!)
glucose + galactose
lactose ( plus water !!)
Name the 2 isomers of glucoses and how they differ ?
Alpha and beta glucose (SEE CARD)
The H and OH are flipped on C1 of a beta molecule.
Name the test from reducing sugars and how to perform it.
Benedict’s Tests
2cm2 of a food sample
2cm2 of the Benedict’s reagent
5 mins in boiling water bath
Name the results of the Benedict’s test
blue copper sulphate is reduced to red copper oxide
blue-green-yellow-orange-red
How to do test for non-reducing sugars?
no colour change seen during the benedicts test
must hydrolyse into monosaccharides
2cm2 food sample + 2cm2 HCl } 5mins in boiling water bath
add sodium hydrogencarbonate ] to neutrilise, use pH paper to test
redo Benedict’s test
What type of glucose are these made from?
Starch
Cellulose
Glycogen
Alpha glucose = starch and glycogen
Beta glucose = cellulose
What is the main role of starch?
energy storage
How is the structure of starch suited to its role?
Insoluble/ doesn’t affect water potential = water not drawn into cell via osmosis
large and insoluble = doesn’t diffuse out of cells
COILED / helix shape compact = lots can be stored in a small space
when hydrolysed it forms alpha glucose which is easily transported and readily used in respiration
branched form has many ends so can be broken down quicker by enzymes.
What is the difference between amylose and amylosepectin?
Amylopectin = branched polysaccharide ( α-1,4- and α-1,6-glycosidic bonds)
Amylose is a linear polysaccharide ( α-1,4-glycosidic bonds)
Amylose is rigid than amylopectin.
Amylose is less readily digested than amylopectin.
What type of glycosidic bonds are in
Starch
Glycogen
Cellulose
1-4 and 1-6 = starch and glycogen
1-4 = cellulose
How is the structure of glycogen suited to its role?
Insoluble/ doesn’t affect water potential = water not drawn into cell via osmosis
large and insoluble = doesn’t diffuse out of cells
compact = lots can be stored in a small space
highly branched = more ends for enzyme
Why is glycogen only found in animal cells?
Animals have a higher metabolic rate hence a higher respiratory rate .
