Carbohydrates, Proteins And Fats Flashcards
What 4 key elements are needed to make biological molecules?
Carbon, hydrogen, oxygen and nitrogen
What are covalent bonds?
Strong bonds formed when two atoms share electrons
What are polymers?
Large molecules made up of many repeating smaller molecules monomers, which are joined together by covalent bonds
What is condensation?
A type of chemical reaction in which molecules are joined together when a covalent bond is formed by the elimination of water, this forms a polymer
What is hydrolysis?
A chemical reaction in which a molecule is broken down when a covalent bond is broken by the addition of a water molecule, this forms monomers
Carbohydrates are?
Molecules containing C, H and O
What are the 3 main functions of carbohydrates?
.energy source-glucose
.energy store-starch (plants) and glycogen (animals)
.mechanical support-cellulose
What are the three main types of carbohydrates?
.monosaccharides
.disaccharides
.polysaccharides
What are monosaccharides, disaccharides, and polysaccharides?
-single , simple sugar molecules such as pentode sugars (5-carbon sugars) and heroes sugars (6-carbon sugars)
-molecules made by joining two single sugars together
-polymers made by joining many simple sugars together
Glucose is a …?
Monosaccharide
There are two different types of glucose which are isomers of each other, this means?
They are heroes sugars with the same molecular formula (C6H12O6) but their atoms are arranged differently
The two forms of glucose are called?
Alpha glucose and beta glucose
Hundreds of alpha glucose molecules join to make?
Starch and glycogen (polysaccharides)
Hundreds of beta glucose Join to make?
Cellulose
Explain ABBA
Alpha has the hydroxide below, beta has the hydroxide abve
Disaccharides are made by?
Joining two monosaccharides by condensation
What does
Alpha glucose + alpha glucose =
Alpha glucose + galactose =
Alpha glucose + fructose =
Maltose + water
Lactose + water
Sucrose + water
During condensation of maltose, what happens?
Water is removed by losing OH from c1 of one alpha glucose molecule and H from C4 of the second a glucose molecule, this forms a 1,4 glycosidic bond
What is a function of starch?
It’s an energy store in plants
Starch is a mixture of?
Two polysaccharides called amylose and amylopectin
Compare the functions of starch and glycogen
Starch is an energy store in plants (starch grains in chloroplasts) whereas, glycogen is an energy store in animals(mainly stores as glycogen granules in liver and muscle cells)
Compare how amylose and glycogen are formed
Amylose and glycogen are both formed from hundreds of alpha glucose molecules joined together by 1,4 glycosidic bonds formed by condensation
Compare the structures of amylose and glycogen
Chains of amylose coil into a compact helix shape in which hydrogen bonds between glucose monomers help hold the helix to keep its shape, whereas, glycogen is highly branded, making it even more compact , these branches are made of 1, 6 glycosidic bonds between alpha glucose molecules
Why are starch and glycogen ideal energy stores ?
-they are helical or branched, meaning they are compact
-large molecules, so can’t leave the cell
-insolvable, so don’t affect the water potential of cells where they are stored
Describe the iodine test for starch
Iodine solution is yellow-brown, when added to starch, the iodine molecules get trapped in the amylose coils, producing a blue black colour
What is cellulose?
A structural polysaccharide in plant cell walls, it is insoluble and very strong. It is a polymer of thousands of beta glucose molecules joined together by 1,4 glycosidic bonds formed by condensation
Describe the structure of cellulose
Because of the structural differences between alpha lactose and beta glucose, every second beta glucose molecules is rotated 180 degrees compared to the first