Macromolecules Flashcards
Roles of sugars and polysaccharides
Food molecules and energy store
Structural support
cell protection
cell-cell adhesion and motility
cell signalling
What are D isomers
straight chain polyhydroxy alcohols (linear form of cyclic sugars)
either an aldehyde or ketone group
at least three carbon units
What are the two glucose enantiomers
alpha and beta glucose
How do the two glucose enantiomers differ, which one is more stable
alpha glucose = OH group pointing down
beta glucose = OH group pointing up
beta is more stable as OH groups are further apart in the molecule
What are the polymers of the glucose enantiomers
alpha = starch and glycogen
beta = cellulose and chitin
How are sugars linked
condensation reaction, removing water forming a 1,4 glycosidic bond
What is the reducing end
the end that is free to become linearised
Glycogen
highly branched glucose polysaccharide
branching increases the number of ends available to be digested for rapid release of glucose
Structure of a ribosome
RNA and protein
active site of ribosome is RNA which is the catalyst for protein synthesis
ribozyme - extra OH on ribose
Structure of a ribosome
RNA and protein
active site of ribosome is RNA which is the catalyst for protein synthesis
ribozyme - extra OH on ribose
What is DNA and RNA used for
DNA = store of genes
RNA = gene expression
What bonds form when nucleotides are polymerised
phosphodiester
What type of pentose is deoxyribose and where is it deoxy at
Aldopentose
deoxy at the 2 position
How many hydrogen bonds between A and T, C and G
A and T = 2
C and G = 3
What are purine and pyrimidine bases
Purine = A and G, two rings
Pyrimidine = T, U, C, one ring
Why does a purine and pyrimidine always complementary base pair
keeps the sugar phosphate backbone the same distance apart all the way along the DNA strand
what is a nucleoside
ribose and base
what is a nucleoside
ribose and base