Carbohydrates Flashcards
(25 cards)
Four major kinds of macromolecules found in living organisms?
Carbohydrates, lipids, proteins and nucleic acids
What do these macromolecules have in common?
- They are large. Made up of smaller units called monomers to make up polymers exclusive of lipids.
-They contain carbon based core (organic material) special groups attached to it that confer specific
chemical properties
-held together by covalent bonds- distinct form that influences function.
What are functional groups?
Functional groups are groups of atoms that occur within organic molecules in conferral with specific chemical properties.
What are functional groups classified as
hydrophobic and hydrophilic
hydrogen bonds and functional groups
hydrogen bonds between functional groups are important to the function of many macromolecules and help them to fold properly and maintain shape needed for functioning correctly.
Hydrogen bonds are also involved in various recognition processes such as
- DNA complementary Base Pairing
-Binding an enzyme to its substrate
Functional groups of Carbohydrates
in general monosaccharides only have one carbonyl group (aldehyde, ketone or acid), and the remaining carbons each bear one hydroxyl group
Polymers from monomer monosaccharide
- Polysaccharide
-Carbohydrates (starch)
Monosaccharides
Monosaccharides are the simplest carbohydrates. Building blocks of more complex carbs.
Aldoses
monosaccharides containing aldehyde group (-CHO) are known as aldoses and regarded as reducing sugars.
Ketoses
monosaccharides containing ketone groups -C=0 known as ketoses and regarded as non reducing sugars.
Disaccharides
Most monosaccharides are rare in nature. Most sugars found in nature are disaccharides. These form when two monosaccharides come together.
How to the two monosaccharides react to form the disaccharide
A process called condensation/dehydration which requires a lot of energy releases water and a glycosidic bond forms which holds the two monosaccharide units together.
What are the three most important disaccharides?
Sucrose (non reducing sugar)
maltose (reducing)
lactose (reducing)
disaccharides and their forming monosaccharides
sucrose = @ glucose + @ fructose
maltose = @ glucose + @ glucose
@ Lactose = @glucose + B galactose
B Lactose = B glucose + B galactose
Dehydration
In this process a covalent bond is formed, one hydroxyl (-OH) is removed from one sub unit and a H+ bond is removed from the other sub unit. (enzymes facilitate this process)
hydrolysis
In instances where the covalent bond needs to be broken, hydrolysis occurs where a hydrogen group is attached to one sub unit and a hydroxyl group is attached to another sub unit.
Condensation polymerization
Monosaccharides undergo a series of condensation reactions adding one unit after another to the chain forming very large molecules (polysaccharides).
Starch is usually produced in plants as a way of storing energy. It exists in two forms
Amylose and amylopectin
(both made from @ glucose
Amylose
An unbranched polymer of @ glucose, the molecules coil into a helical structure. It forms a colloidal suspension in hot water.
Amylopectin
A branched polymer of @ glucose completely insoluble in water
Glycogen
Glycogen is amylopectin with very short distances between branching side chains. Starch from plants is hydrolysed in the body to form glucose, which is then passed into the cell and used in metabolic reactions. There in the cell the glucose can be polymerized to form glycogen which acts as a carbohydrate energy store.
Cellulose
Another polymer made from glucose however it is made from B glucose molecules and the polymer molecules are straight
Cellulose makes up the cell walls in plant cells. Which are tougher than cell membranes because
because of the arrangement of glucose polymer chains and hydrogen bonding to neighboring chains. Cellulose is not easily hydrolysed so therefore cannot be digested by humans for a source of energy
