Unit 1: biological molecules Flashcards
what are organic compounds made of?
Carbon , oxygen, hydrogen
(proteins and nuclei acids contain nitrogen)
what are polymers?
long molecules made of monomers
name 3 examples of a polysaccharide
starch, glycogen, cellulose
what is a polysaccharide generally made of?
many sugar molecules (monosaccharides)
what are carbohydrates?
‘sugar’ molecules composed of primarily Carbon, Hydrogen, Oxygen
in a ratio of 1:2:1
what’s the common ending of sugars
-osę
except for glycogen and starch bc they’re made of more than 1 sugar
what are the three types of carbohydrates?
mono-
di-
polysaccharides
what is a monosaccharide?
the simplest sugars.
eg Glucose, and Fructose. Glucose is called a hexose as it has six carbons in its
structure while fructose is a pentose as it has 5.
what are disaccharides?
sugars formed when 2 monosaccharides join together in a condensation reaction
name to examples of a disaccharide
maltose (formed during the malting of barley - glucose + glucose)
sucrose (formed with a glycosidic bond - glucose + fructose)
how is a polysaccharide formed?
many monomers are polymerised together through condensation reactions. E.g. Amylopectin (a polymer of glucose)
E.g. Starch
what is a polysaccharide for?
used to store energy for later & to support plants
What does the condensation reaction do?
It allows for the formation of disaccharide molecules (maltose + sucrose) and eventually polysaccharide molecules.
why is a glycosidic bond strong?
it’s covalent
describe the maltose condensation reaction
2 glucose molecules react to produce maltose a bond is formed between the carbon 1 of one glucose molecule and the carbon 4 of another. = a glycosidic bond.
If these are alpha glucose molecules = α 1,4 glycosidic bond
what is the most common polysaccharide in plants?
cellulose - makes up 40-60% of the cell wall & most common polymer on earth
why is cellulose strong?
made of a long chain of beta-glucose molecules –100 to 15,000 glucose molecules
rigid chain as each unit alternates and gives structural strength
what is made of pure cellulose?
cotton boll
what are the most important storage polysaccharides?
amylose and amylopectin
what is amylose?
A long chain of alpha-glucose, several hundred to several thousand molecules long.
what is amylopectin?
more complex, often made up of 50,000 molecules.
what are amylose and amylopectin used for?
making starch grains. Most starch grains are about 20% amylose and 80% amylopectin
what stores glucose in plants?
starch
what stores glucose in animals?
glycogen
intro to glycogen
glycogen is the molecule that is used to store glucose in animals. It accounts for about 5% of the weight of the liver and 0.5% of the weight of the muscles in the body
describe the structure of glycogen
similar to amylopectin
heavily branched molecule containing straight chains of glucose units connected by a,1:4 linkage. The branching that results from the a 1:6 linkage is much more frequent in glycogen than in amylopectin, occurring every 8-12 glucose units rather than ever 24-28.
