carbohydrates

• What elements make up carbohydrates?

  C, H, O
• what are the 3 structures of carbs

  monosaccharides: single sugar

  disaccharides: double sugar

  polysaccharides: multiple monosaccharides joined
• examples of monosaccharides

  glucose, fructose, ribose, deoxyribose
• exampes of disaccharides

  lactose, maltose, sucrose
• examples of polysaccharides

  starch, glycogen, cellulose
• what is the general formula for carbs?

  CnH2nO
• what is the difference between pentose and hexose sugars + examples

  pentose have 5 carbon atoms e.g. ribose/deoxyribose and hexose have 6 carbon atoms e.g. glucose
• what are ribose and deoxyribose and how are they different

  structural isomers - ribose has a H atom and one OH group attached to carbon 2, deoxyribose has 2 H atoms
• what structure do pentose and hexose sugars have

  a ring structure
• what are the properties of glucose

  - major energy source for most cells

  - soluble

  - polar

  - main form that carbs are transported around animals
• why is glucose polar and soluble

  it has hydrogen bonds between the hydroxyl groups and water molecules
• What are the two isomers of glucose?

  alpha and beta
• what is the difference between alpha and beta glucose

  the position of the OH group attached to carbon 1: in alpha, it's below the carbon and in beta it's above the carbon
• What is the isomer of glucose?

  fructose
• How is a glycosidic bond formed?

  a condensation reaction between two monosaccharides
• what are the monomers of maltose

  Alpha glucose + alpha glucose
• what are the monomers of sucrose

  alpha glucose + fructose
• what are the monomers of lactose

  alpha or beta glucose + galactose
• What are storage polysaccharides? + what is its monomer

  starch (plants) and glycogen (animals) - alpha glucose
• what is the structural polsyaccharides and what is its monomer

  cellulose - beta glucose
• what is starch made up of

  amylose and amylopectin
• describe the structure of amylose and what property this causes

  unbranched straight chain which is wound into a helix shape, all 1 4 glycosidic bonds so its very compact - hard to hydrolyse
• describe the structure of amylopectin and what property this causes

  branched with 1 4 and 1 6 glycosidic bonds so it's less compact - easier the hydrolyse
• describe the structure of glycogen

  highly branched with 1 6 glycosidic bonds
• where and how is glycogen stored

  as small granules stored in muscles and the liver
• properties of glycogen

  less dense and more soluble than starch and is hydrolysed more rapidly = higher metabolic requirements of animals than plants
• what are 2 properties of starch and glycogen

  - large so insoluble = have no effect on water potential - so no water enters the cell by osmosis

  - compact - lots can be stored in a small space
• Where is cellulose found?

  the main part of cell walls
• describe the structure of cellulose+ how is it adapted for its function

  long chains of beta glucose joined by 1 4 glycosidic bonds. The chains form rope-like microfibrils which are layered to form a network --> strong fibres provide structural support
• How do beta glucose molecules form glycosidic bonds

  every other glucose molecule is rotated 180° so they can both contribute to the H2O for condensation
• why is cellulose strong

  the hydrogen bonds between the chains of beta glucose due to the inversion
• what is the function of glucose? + how is it adapted

  main energy source in animals and plants. its structure makes it soluble so it can be easily transported. its bonds contain lots of energy
• describe the condensation reaction forming a glycosidic bond?

  a H atom on one monosaccharide bonds to an OH group on the other, releasing a molecule of water
• what is the function of starch + how is it adapted?

  energy storage in plants --> starch is broken down into glucose to release energy
• what is the difference between starch and glycogen?

  glycogen is a lot more branched than starch