1.1-2 Monomers+ Polymers, Carbohydrates Flashcards
what are monomers
-smaller, repeating molecules / units from which larger molecules / polymers are made
what are polymers
-molecules made from many (a large number) identical / similar monomer molecules
what happens in a condensation reaction
- 2 molecules join together
- forming a chemical bond
- releasing a water molecule
what happens in a hydrolysis reaction
- 2 molecules separated
- breaking a chemical bond
- using a water molecule
examples of monomers
-nucleotides
-monosaccharides eg glucose
-amino acid
example of polymers
-polynucleotides (dna/rna)
-polysaccharides (starch)
-polypeptides (protein)
what are monosaccharides
- monomers from which larger carbohydrates are made
- glucose, fructose, galactose
describe the structure of alpha glucose
-on the right,
-H on the top and OH on the bottom
describe the difference between the structure of alpha glucose and beta glucose
- isomers - same molecular formula but differently arranged atoms
-OH group is below carbon 1 in α-glucose but above carbon 1 in β-glucose
what are disaccharides and how are they formed
- two monosaccharides joined together with a glycosidic bond
- formed by a condensation reaction, releasing a water molecule
list 3 common disaccharides
-maltose
-sucrose
-lactose
monosaccharides that make up maltose
glucose + glucose
monosaccharides that make up sucrose
glucose + fructose
monosaccharides that make up lactose
glucose + galactose
what are polysaccharides and how are they formed
- many monosaccharides joined together with glycosidic bonds
- formed by many condensation reactions, releasing many water molecules
function of starch
-energy store in plant cells
structure of starch
- polysaccharide of α-glucose
- some has 1,4-glycosidic bonds so is unbranched (amylose)
- some has 1,4- and 1,6 glycosidic bonds so is branched (amylopectin)
function of glycogen
-energy store in
animal cells
structure of glycogen
-polysaccharide made of α-glucose
-1,4- and 1,6-glycosidic bonds → branched
explain how the structure of starch relates to its function
- helical → compact for storage in cell
- large, insoluble polysaccharide molecule → can’t leave cell / cross cell membrane
- insoluble in water → water potential of cell not affected (no osmotic effect)
explain how the structure of glycogen relates to its function
- branched → compact / fit more molecules in small area
- branched → more ends for faster hydrolysis → release glucose for respiration to
make ATP for energy release - large, insoluble polysaccharide molecule → can’t leave cell / cross cell membrane
- insoluble in water → water potential of cell not affected (no osmotic effect)
describe the function of cellulose
- provides strength and structural support to plant / algal cell walls
describe the structure of cellulose
- polysaccharide of β-glucose
- 1,4-glycosidic bonds so forms straight, unbranched chains
- chains linked in parallel by hydrogen bonds, forming microfibrils
explain how the structure of cellulose relates to its function
- every other β-glucose molecule is inverted in a
long, straight, unbranched chain - many hydrogen bonds link parallel strands
(crosslinks) to form microfibrils (strong fibres) - hydrogen bonds are strong in high numbers
- so provides strength to plant cell walls
