Biological Molecules Flashcards
Whats the single unit in carbohydrates called
Monosaccharides
Name 3 monosaccharides
Glucose galactose fructose
Whats a condensation reaction
Joining of molecules to form a chemical bond excluding water
What does condensation of 2 monosaccharides produce
Disaccharides
What bond is formed between molecules in condensation reactions
Glycosidic bond
What disaccharide is made from 2 glucose molecules
Maltose
What disaccharide is made from glucose and fructose
Sucrose
What disaccharide is made from glucose and galactose
Lactose
Starch is a polymer of what glucose
Starch has a ———- structure
Which makes it very ———-
Starch is soluble or insoluble
So does it affect water potential
Starch is a polymer of alpha glucose
Starch has a helical structure
Which makes it very compact
Starch is insuluble
So it doesn’t affect water potential
How do u test for starch
Add iodine if present sample turns black
Glycogen is a polymer of —— glucose
Is it more branched
Glycogen is a polymer of alpha glucose
Its more highly branched so it can be more readily broken down to glucose for uses in respiration
Which is y its used as a storage molecule in animal cells
Cellulose is a polymer of —— glucose
Polymer of beta glucose
Molecules of beta glucose are inverted
Cellulose is in straight chains
Benedicts test for reducing and non reducing sugard
Add benedicts reagent which is blue to sample
Heat sample
If reducing sugar present brick red precipitate
‘If negative solution stays blue
To test for non reducing-
Add hydrochloric acid to negative test and boil to hydrolyse non reducing sugar
Add alkali to neutralise solution because its very acidic ( add sodium hydrogen carbonate )
Perform Benedict test and presence of brick red precipitate shows we have non reducing sugar
Example of non reducing sugar
Sucrose
Example of reducing sugars
Glucose galactose fructose
