topic 1- Monomers & Polymers and carbohyrdates Flashcards
(30 cards)
What are monomers?
Monomers are the smaller units from which larger molecules are made.
What are polymers?
Polymers are molecules made from a large number of monomers joined together.
What are examples of monomers?
Monosaccharides, amino acids and nucleotides.
What is a condensation reaction?
A condensation reaction joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water.
What is a hydrolysis reaction?
A hydrolysis reaction breaks a chemical bond between two molecules and involves the use of a water molecule.
What are monosaccharides?
Monosaccharides are the monomers from which larger carbohydrates are made.
What are examples of monosaccharides?
Glucose, galactose and fructose.
what is formed between 2 monosaccharide and how?
A condensation reaction between two monosaccharides forms a glycosidic bond. A disaccharide is formed.
How is maltose formed?
Maltose is a disaccharide formed by condensation of two glucose molecules.
How is lactose formed?
Lactose is a disaccharide formed by condensation of a glucose molecule and a galactose molecule.
How is sucrose formed?
Sucrose is a disaccharide formed by condensation of a glucose molecule and a fructose molecule.
What is an isomer?
Two molecules with the same molecular formula but a different structure.
what are the two isomers of glucose?
α-glucose and β-glucose.
Describe the difference between alpha glucose and beta glucose.
Hydroxyl on alpha glucose is at the bottom. The hydroxyl on beta glucose is at the top.
How are polysaccharide formed?
Polysaccharides are formed by the condensation of many glucose units.
give examples of polysaccharides and how they are formed.
Glycogen and starch are formed by the condensation of α-glucose.
Cellulose is formed by the condensation of β-glucose.
What is starch?
Starch is what plants store as excess glucose. When plants need more glucose for energy, starch is broken down into glucose.
What mixture of polysaccharides does starch contain?
Amylose and Amylopectin.
What is the structure and function of starch?
Amylose is a long, unbranched chain of alpha glucose, The angles of the glycosidic bonds give it a coiled structure. This makes it very compact.
Amylopectin is a long, branched chain of alpha glucose. Its has got many side branches.
relate the structure of starch to its function.
The coiled and compact structure of amylose allows a lot of energy to be stored, therefore making it a good energy storage.
The side branches on amylopectin allow enzymes to break down the molecule and make it easier to break the glycosidic bonds. This means that energy can be released quicker for important functions like respiration.
Starch is insoluble in water so doesn’t affect water potential, so water cannot enter cells by osmosis, which would make them swell.
What is the test for starch?
Add iodine dissolved in potassium iodide solution to the test sample. If starch is present the sample changes from browny- orange to a dark, blue-black colour.
What is glycogen?
Glycogen is the main energy storage in animals and it stores excess glucose to be used later on, such as respiration.
What is the structure of glycogen?
Glycogen has many side branches, similar to that of amylopectin.
Relate the structure of glycogen to its function.
The side branches in glycogen allow it to be broken down much quicker by enzymes, meaning that energy can be released quickly as well.
Since it is highly branched, a high amount of energy is released. The energy released can be used for important processes such as respiration.
Glycogen is also insoluble and therefore do not affect the water potential, so water cannot enter by osmosis.
