Last revision Flashcards
Describe a condensation reaction
A chemical process where two molecules are bonded together to make a larger more complex biomolecule with the loss of H20. It is the basis of synthesis of all complex macromolecules such as carbohydrate polymers: glycogen, starch and cellulose.
Describe Maltose condensation reaction?
Two alpha-glucose molecules in close proximity have a free -OH at position C-1 and C-4. H20 is created and released. Remaining -O- creates glycosidic bond, said to be a-1,4, glycosydic link. This can be repeated many times to create a polysaccharide.
Describe a hydrolysis reaction
Hydrolysis means water splitting. The H20 molecule breaks the bond of two biomolecules by adding a H and -OH to either side of the glycosdic bond, replacing the H20 released during the condensation reaction.
Describe Hydrolysis of Maltose?
Digestive enzyme Matlase catalyses the hydrolysis of matlose. Enzyme is located in the phospholipid bilyaer of the epithelial cells that line the villi of the small intestines. Either side of the glycosidic bond receive a -H and -OH, replacing the H20 from condensation, displacing the glycosidic bond, and creating two monosaccharides.
What is facilitated diffusion?
Passive movement along concentration gradient with an integral membrane protein forming a channel or pore.
Why are Polysaccharides use for storing energy?
Monosaccharides are water soluble thus cannot be stored in large amounts as they would seriously impair the osmotic balance of the cell, eventually leading to death. Polysaccharides such as glycogen and starch are insolube, thus a much more useful form of storage as they do not influence osmotic balance as much.
How is glycogen formed?
Successive condensation reactions between cytoplasmic glucose molecules.
Describe branching of polymers?
Starch: Moderately
Glycogen: Highly
Cellulose: Unbranched, straight chains
What do glycoproteins and glycolipids do?
They are carbohydrates attached to proteins and phospholipids in the cell membranes and play a role in CELL TO CELL COMMUNICATION.
