Unit 1: Carbohydrates Flashcards
what do organic molecules contain?
Carbon
Give an example of a monomer
glucose
Give an example of a polymer
starch, cellulose, glycogen
What is the combination of two small molecules to form a large molecule called?
Dehydration synthesis reaction or condensation reaction
In what reaction do large molecules break down to form small molecules?
Hydrolysis reaction
what elements make up carbohydrates?
carbon, hydrogen and oxygen
what are carbohydrates?
molecules that function as energy sources or structural components of cells
what is glucose chemical formula
C6H12O6
Excess glucose is stored as what and where?
glycogen in the liver and muscle tissue
what are optical isomers
molecules that are structurally identical but are mirror images of each other
which form of glucose do enzymes recognise?
D-glucose
what is the ring structure of glucose known as?
pyranose ring
how do you known which ring is alpha Dglucose and beta Dglucose?
If the hydroxyl group attached to C1 of the ring is above the plane then the resulting ring is known as the beta form.
If the hydroxyl group attached to the C1 of the ring is below the plane, the resulting ring is known as the alpha form.
what bonds does amylose have and what are they made up of?
glucose and a(1,4) glycosidic bonds
what structure does amylose have?
straight chain
How is cellulose formed?
dehydration reaction between beta glucose molecules
top tip, ABBA, what does it stand for?
Alpha Below Beta Above
what is an alpha 1,4 glycosidic bond?
condensation reaction between Oh group of C1 and OH group of C4 forming an alpha 1,4 glycosidic bond.
two monomers joined together is called?
a disaccharide
what are homopolymers and heteropolymers?
homopolymers have the same constituent molecules
heteropolymers have different constituent molecules
starch glycogen and cellulose are what in water
insoluble
what is starch?
is a storage compound in plants
what is starch made up of?
alpha glucose monomers
what is amylopectin made up of and what bonds does it have?
glucose, alpha 1,4 on long chain and alpha 1,6 on branched chain
what is glycogen?
storage glucose in animals
what is glycogen composed of and what bonding does it have?
Dglucose and alpha 1,4 and alpha 1,6 glycosidic bonds
what structure is glycogen?
highly branched structure
what type of structure is more rapidly synthesised and hydrolysed?
branched
why do organisms build storage carbohydrates?
a high concentration of glucose tends to draw water into a cell by osmosis leading to problems for the cell. huge starch and glycogen molecules are insoluble, they do not affect osmosis and osmotic problems are avoided.
how is cellulose formed?
dehydration reaction between beta glucose molecules
what breaks down cellulose
cellulase
what is cellulose made up of?
beta Dglucose and joined by beta 1,4 glycosidic bonds
what is the structure of cellulose
head and tail structure and have hydrogen bonds between parallel chains
how can starch, glycogen and cellulose be distinguished from one another?
with iodine. starch - deep blue
glycogen - dark brown
cellulose - no stain
all due to way iodine gets trapped in polysaccharide
what are the two forms of starch?
amylose and amylopectin
40 cellulose chains make up what?
a fibril that are arranged in layers to make up the cell wall
