Lecture 4a - How Do Molecules of Life Differ from Non-Living Matter? - polysaccharides Flashcards
What are polysaccharides (carbohydrates) made from?
joining together of monosaccharides (sugars)
How is a 1’-4’ glycosidic bond formed?
- OH on carbons 1’ and 4’
- react in a condensation reaction
- eliminating water
Why can the process of 1’-4’ glycosidic bonds repeat?
as either the 1’ or the 4’ carbon are free on each glucose molecue
what is the difference between alpha and beta glucose?
in alpha glucose the hydroxyl group on the 1 carbon point downwards whereas in beta glucose they point upwards
What happens as the chain length of alpha glucose increases?
it bends around
what happens as the chain length of beta glucose increases?
the chain remains straight
What is the difference between a 1-4 alpha glucose bond and a 1-4 beta glucose bond?
alpha-> both the hydroxyls involved in bonding point downwards
beta -> C 4 hydroxyl points down and C 1 hydroxyl points up
What causes an alpha chain to bend?
due to both the hydroxyls involved in the glycosidic bond pointing downwards, creating bending
What can break apart carbohydrates?
adding water, causing hydrolysis
What is a use of a curved alpha glucose chain?
- 2 curved chains can wrap around each other using hydrogen bonds, forming a helix.
- creating amylose which makes up starch
- which is used as a long term storage molecule in plants
What is a use of a straight beta glucose chain?
- interact by hydrogen bonds to form solid structures
- making cellulose
- which is used to give structure to plant cells
What causes branching in glucose chains?
1-6 glycosidic bonds
What is an example of a branched glucose chain?
glycogen -> short term storage in animals
what can a 1-4 glycosidic bond form?
chains
what can a 1-6 glycosidic bond form?
branches
