Carbohydrates and lipids

• Explain how the structures of amylopectin and glycogen make them suitable for storing energy?

  -highly branched allowing rapid hydrolysis for the release of glucose

  -insoluble so no osmotic effect

  -compact so more energy stored in a small space

  -insoluble and large so cannot diffuse directly out of cell
• Describe the structure of starch?

  polysaccharide of alpha glucose

  has unbranched chains which are joined together by 1-4 glycosidic bonds ( amylose )

  has branched chains ( amylopectin ) which are joined by a 1-6 glycosidic bond
• Describe the formation of glycogen from glucose?

  condensation reaction

  forming 1-4 and 1-6 glycosidic bonds
• Describe how the structure of glycogen is related to its function as a storage molecule?

  highly branched with 1,4 and 1,6 glycosidic bonding for rapid hydrolysis and release of glucose

  compact so more can be stored

  insoluble to prevent osmotic effect
• Describe the reaction which forms a disaccharide between to alpha glucose molecules?

  a condensation reaction

  between the hydroxyl groups on the molecules

  forming a 1,4 glycosidic bond and water
• Describe the effect that a lipoprotein containing a saturated triglyceride would have on blood cholesterol?

  it would form LDL as it is saturated

  so blood cholesterol would increase

  because LDLs transport cholesterol, but if cells are saturated with cholesterol, it remains and accumulates in blood
• what are the similarities between glycogen and disaccharides?

  both contain Carbon, hydrogen and oxygen

  both contain glycosidic bonds

  both contain glucose
• what are the differences between glycogen and disaccharides?

  glycogen has two types of glycosidic bonds (1,4 and 1,6) while disaccharides have only 1,4 bonds

  glycogen is made up of glucose only while disaccharides can contain glucose and another monosaccharide
• How can polysaccharides be broken down by enzymes?

  Glycosidic bond is broken

  by the addition of water (hydrolysis)
• Describe the structure of an unbranded polysaccharide?

  a chain of many monosaccharides

  joined by 1,4 glycosidic bonds
• What is a monosaccharide?

  simple sugars which act as monomers/building blocks of larger, more complex carbohydrates
• what is a disaccharide?

  A disaccharide is a type of carbohydrate composed of two monosaccharide units joined together by a glycosidic bond.
• what is a polysaccharide?

  A complex carbohydrate made up of a repeat unit of monosaccharides bonded by glycosidic bonds, through a condensation reaction where water is reduced as a by-product
• What is this monosaccharide?

  Alpha glucose (H is above carbon 1)

  
• What are the 3 features of glucose?

  primary source of energy for production of ATP in cellular respiration (stores energy in bonds), soluble (easily moves into cells for immediate use), simple structure (doesn’t need to be broken down before use)
• why is glucose immediately available for use?

  always available in the bloodstream from digestion, easily hydrolyzed from glycogen
• how are glycosidic bonds formed?

  forms between 1,4 carbon or 1,6 carbon, water molecule is removed from hydroxyl and hydrogen during a condensation reaction
• How can glycosidic bonds be broken?

  hydrolysis
• What are the two types of starch?

  amylose

  amylopectin
• Describe the structure of amylopectin?

  A polysaccharide made up of alpha glucose monomers, a component of starch which is an energy storage carbohydrate in plants, has a 1,4 glycosidic bonded glucose chain with 1,6 glycosidic bonded branches
• what is the function of amylopectin and amylose?

  energy storage
• What features of amylopectin make it suitable for energy storage

  HIGHLY BRANCHED Leading to rapid hydrolysis for immediate release of glucose, insoluble (no osmotic effect), large and insoluble (will not diffuse out of cell) compacT (a lot of energy can be stored in a small amount of space)
• Compare amylopectin and glycogen

  Both are polysaccharides made up of a repeat unit of alpha glucose

  Both store energy in the form of glucose

  both made up of C,H,O only

  both have glycosidic bonds formed through condensation reaction
• contrast amylopectin and glycogen?

  Glycogen is a more highly branched molecule, this is because it is found in animals which have higher metabolic Requirements that plants.

  Amylopectin is found in starch in plants while glycogen is found in liver and muscle cells in animals
• Compare and contrast amylose and amylopectin?

  Both are polysaccharides consisting of alpha glucose monomers held together by glycosidic bonds. Both are energy storage in starch in plants.

  Amylose has a linear chain structure of 1,4 glycosidic bonds while amylopectin has a branched structure of 1,4 and 1,6 glycosidic bonds, amylose has a helical compact structure for storage long-term while amylopectin is more efficient for rapid release of glucose
• What type of bond is present between the glycerol molecule and the three fatty acid molecules?

  ester bond
• Name the circled region on the triglyceride molecule

  ester bond

  
• how are ester bonds formed?

  condensation reaction where hydrogen is removed from the glycerol and hydroxyl is removed from each fatty acid molecule
• Hydrolysis results in the bonds between glycerol and fatty acids to be broken and water to be 


  used
• Which type of reaction is involved in the digestion of cellulose by enzymes?

  hydrolysis
• The role of starch is to be a store of energy for

  Plants
• Starch is a polymer of which monosaccharide?

  alpha glucose
• A starch molecule is helical in shape, explain why this shape is important to its function in cells?

  it is more compact, maning it occupies less space and can store more glucose per unit space occupied
• Diagram shows a cellulose molecule, name part A and B

  A —> beta glucose

  B —> glycosidic bond

  
• Name the similarities between cellulose and starch?

  both are polymers made up of simple sugars

  both are joined by a condensation reaction and can be broken down by hydrolysis

  both are made up of Carbon, Hydrogen, Oxygen

  Both are insoluble

  both contain 1,4 glycosidic links
• Name 4 differences between cellulose and starch?

  starch is coiled/ helical shape and branched, cellulose is unbranched and not coiled

  Starch is made up of alpha glucose, cellulose is made up of beta glucose

  in starch all glucose are the same way up, while in cellulose the directionality alternates

  starch Have no H bonds, cellulose do
• How is the structure of cellulose related to its function in plant cells?

  long straight unbranched chains of glucose, joined by strong hydrogen bond, this provides strength and support
• Distinguish between the structures of amylopectin and amylose?

  amylose is a linear, coiled chain containing only 1,4 glycosidic bonds while amylopectin is uncoiled (both 1,4 and 1,6 glycosidic bonding)

  amylose is unbranched, amylopectin is highly branched
• Why do lipids store more energy than carbohydrates

  Higher ratio of C-H compared to oxygen atoms. Many C-H bonds allow a lot of energy to be released upon breaking due to formation of very high energy releasing molecules. While carbohydrates have a higher oxygen ratio and fewer C-H bonds