Carbohydrates Flashcards
Why is the glucose molecule in a C shape?
Because of the 3-D angles of the chemical bonds
What does the ABBA acronym stand for?
Alpha below, Beta above
Which Carbon does the OH group attach to that determines wether it is Alpha or Beta amylase?
Carbon 1
How are glucose molecules linked together?
Enzyme catalysed reactions
What reaction occurs between Carbon 1 and Carbon 4 when they are linked together?
Condensation reaction
What type of bond links beta-glucose monomers?
beta-1,4-glycosidic bonds
What is starch made from?
The excess glucose made during photosynthesis can be built up to form starch in plant cells.
What is starch made up of?
Thousands of alpha glucose monomers
What are the two forms of starch?
Amylose and Amylopectin
What is the structure of amylose?
Long linear molecule of many glucose monomers joined by alpha-1,4-glycosidic bonds. Twisted. Long unbranched helix.
What is the structure of amylopectin?
Long chains of alpha-1,4 linked glucoses. Side branches every 25-30 units. Alpha-1,6-glycisidic bonds between chain and branch.
What is glycogen used for?
Made in animal cells for energy storage
How is the structure of glycogen different from amylopectin?
Branches occur ever 10-12 units.
How is it that glucose can be released quicker from glycogen than amylopectin?
Glucose is removed from he end of the chain when required.Glycogen has more ends than amylopectin.
Why don’t organisms just store glucose?
A high concentration of glucose draws water into the cell by osmosis leading to problems within the cell.
Why are long chain molecules more effective than glucose for storing energy?
They are insoluble, they do not affect osmosis and so osmotic problems are avoided.
What does cellulose do?
It is the structural carbohydrate providing support and rigidity in plant cell walls.
What is the structure of cellulose?
Beta-glucose linked by beta-1,4-glycosidic bonds
Does cellulose have branches?
No
How is the rigid straight chain of cellulose produced?
Every second monomer is inverted
What does the inversion of monomers lead to?
Hydrogen bonding beween cellulose chains.
What are fibrils made from?
About 40 cellulose chains which are aligned and cross-linked
What is the cell wall made of?
Many fibrils arranged in layers
