Polysaccharides: starch, glycogen, and cellulose

• What are polysaccharides made from?

  Many monosaccharides linked together
• How is glycogen stored in animal cells?

  As compact granules
• If you wanted to study the detailed structure of amylose, which microscope technique would you use?

  Scanning electron microscope (SEM)
• What type of bonds link monosaccharides in polysaccharides?

  Glycosidic bonds
• How does glycogen compare to plant amylopectin in structure?

  Glycogen is more highly branched
• What is the chemical structure of cellulose?

  • Cellulose is a polysaccharide composed of repeating units of glucose
  • The glucose units are linked together by β-1,4-glycosidic bonds
  • The structure forms long, linear chains that can hydrogen bond with each other
• How does muscle glycogen function during exercise?

  Supplies glucose directly for muscle contraction
• Why is the structure of amylopectin different from amylose?

  Amylopectin has branched chains, while amylose has a straight chain structure
• How does the structure of cellulose contribute to its function in plant cell walls?

  • The long, linear chains of cellulose form strong, rigid microfibrils that provide structural support and protection to plant cell walls
  • The extensive hydrogen bonding between cellulose chains makes the cell walls resistant to compression and tension
  • The cellulose microfibrils are embedded in a matrix of other polysaccharides and proteins, creating a tough, flexible composite material
• How does the structure of cellulose differ from that of starch, another important plant polysaccharide?

  Cellulose has a linear, unbranched structure with β-1,4-glycosidic bonds, while starch has a branched structure with α-1,4 and α-1,6-glycosidic bonds
• How does the branched structure of amylopectin affect its properties compared to the straight chain structure of amylose?

  The branched structure of amylopectin makes it more soluble and easier to digest than the straight chain amylose
• What are the two polysaccharides that make up starch?

  Amylose and amylopectin
• What is the function of the cellulose microfibrils in the plant cell wall?

  They provide structural support and rigidity to the plant cell
• What properties of cellulose make it suitable for plant cell walls?

  • Strong
  • Rigid
  • Insoluble
• What is the structural difference between the glucose units in amylose and amylopectin?

  • The glucose units in amylose are linked by α-1,4 glycosidic bonds
  • The glucose units in amylopectin are linked by α-1,4 and α-1,6 glycosidic bonds
• How are multiple cellulose chains held together?

  By hydrogen bonds
• How are the cellulose microfibrils arranged in the plant cell wall?

  • Cellulose microfibrils are arranged in layers
  • The microfibrils are aligned in different directions in each layer
  • This criss-cross arrangement provides structural strength to the cell wall
• What role does starch play in the physical structure of plant cells?

  It contributes to rigidity and shape
• How is amylopectin stored in plant cells?

  As large grains
• What is the function of liver glycogen?

  Regulates blood glucose by releasing glucose
• What are the key structural features of cellulose that give it its unique properties?

  • The linear, unbranched structure allows for tight packing and formation of hydrogen bonds
  • The β-1,4-glycosidic bonds make the structure rigid and resistant to hydrolysis
  • The hydroxyl groups on the glucose units allow for extensive hydrogen bonding, contributing to cellulose's strength and stability
• What type of bonds link glucose molecules in cellulose?

  Beta(1→4) glycosidic bonds
• What is the primary function of glycogen in animals?

  Energy storage and blood glucose regulation
• What type of bond is found in glycogen?

  α(1→4) / α(1→6)
• What are the main components of the cellulose molecule?

  • Glucose molecules
  • Hydrogen bonds between glucose molecules
  • Glycosidic bonds between glucose molecules
• How does the structure of starch differ from glycogen?

  Starch is linear/branched, glycogen is highly branched
• What characteristic of cellulose fibers helps them resist stretching and compression?

  Long, unbranched chains
• What type of bonds join glucose molecules in glycogen's main chains?

  α(1→4) glycosidic bonds
• How do the shapes of the four macromolecules differ?

  • Cellulose: Linear, straight chains
  • Starch: Helical, coiled chains
  • Amylopectin: Branched, tree-like structure
  • Glycogen: Highly branched, tree-like structure
• What are the key properties of cellulose fibers?

  • Long and unbranched chains
  • Strong and resistant to stretching
  • Provide shape and strength to plants
• What type of bond is found in starch?

  α(1→4) / α(1→6)
• What is the chemical formula for glucose, the monomer of cellulose?

  $C_6H_{12}O_6$
• What are the general properties of polysaccharides?

  • Large size: Composed of numerous monosaccharide units
  • Insoluble in water: Due to size and arrangement
  • No sweetness: Unlike monosaccharides and disaccharides
• What type of bond is found in cellulose?

  β(1→4)
• If you wanted to observe the detailed structure of the cellulose microfibrils, which type of microscope would you use?

  Scanning electron microscope (SEM)
• What is the primary function of starch in plants?

  Energy storage and physical structure
• How does the structure of cellulose contribute to the function of plant cell walls?

  • Cellulose microfibrils provide structural rigidity and tensile strength
  • The criss-cross arrangement of microfibrils resists compression and stretching
  • This allows plant cells to maintain their shape and withstand turgor pressure
• What is the animal storage form of glucose?

  Glycogen
• What are the main structural features of glycogen compared to amylopectin?

  • Glycogen: More branched, located in animal cells, stored as compact granules
  • Amylopectin: Less branched, located in plant cells, stored as large grains
• What type of bonds create branches in glycogen?

  α(1→6) glycosidic bonds