Unit 1

• What is the function of starch in plants?

  Major energy source in most diets
• Where is starch primarily found in plants?

  In seeds and storage organs
• What are the two polysaccharides that make up starch?

  Amylose and amylopectin
• What type of glycosidic bonds are found in starch?

  C1-4 and C1-6 glycosidic bonds
• How does the helical structure of starch relate to its function?

  It allows for compact storage of energy
• Why is starch insoluble in water?

  It doesn't affect water potential
• How do the branched chains of starch benefit its function?

  They allow for more efficient hydrolysis
• What is the primary function of glycogen in animals?

  Main storage of energy
• Where is glycogen primarily stored in the body?

  In muscle and liver cells
• What type of glycosidic bonds are found in glycogen?

  C1-4 and C1-6 glycosidic bonds
• How does the branched structure of glycogen relate to its function?

  It allows rapid hydrolysis into glucose
• What is the function of cellulose in plants?

  Provides structural strength in cell walls
• What gives cellulose its strength?

  Hydrogen bonds between parallel chains
• How does cellulose withstand turgor pressure?

  High tensile strength allows stretching
• What type of glycosidic bonds are found in cellulose?

  C1-4 glycosidic bonds
• What is the significance of microfibrils in cellulose?

  They provide collective strength to cell walls
• What are the steps in the Benedict's test for reducing sugars?

  1. Add Benedict's reagent to the sample.
  2. Heat in a boiling water bath for 5 minutes.
  3. Observe color change from blue to green, yellow, orange, or brick red.
• What is the procedure for testing non-reducing sugars using Benedict's test?

  1. Hydrolyze the sugar with hydrochloric acid.
  2. Neutralize with sodium hydrogen carbonate.
  3. Add Benedict's solution and heat in a boiling water bath for 5 minutes.
• What color indicates a positive result for reducing sugars in the Benedict's test?

  Brick red
• What is the positive result for the iodine test for starch?

  Orange to blue/black
• What elements do lipids contain?

  Carbon, hydrogen, and oxygen
• What is the structure of triglycerides?

  1 glycerol and 3 fatty acids
• How are triglycerides formed?

  Through condensation reactions releasing water
• What is the primary function of triglycerides?

  Storage molecules for energy
• Why are triglycerides insoluble in water?

  Hydrophobic fatty acid tails face inwards
• What is the structure of phospholipids?

  1 glycerol, 1 phosphate group, 2 fatty acids
• What is the function of phospholipids?

  Form phospholipid bilayer and micelles
• How do phospholipids contribute to cell membranes?

  Hydrophilic heads attract water, tails repel
• What are the two types of fatty acids?

  Saturated and unsaturated
• What is the difference between cis and trans unsaturated fatty acids?

  Cis has H on the same side, trans opposite
• What is the procedure for the lipid test using ethanol and water?

  1. Add ethanol to the sample.
  2. Add water and shake.
  3. Observe for a white/milky emulsion.
• What are the monomers of proteins?

  Amino acids
• What elements do proteins contain?

  Carbon, hydrogen, oxygen, nitrogen, sulfur
• What is the structure of an amino acid?

  NH₂, COOH, and R group
• How are dipeptides formed?

  Through condensation reactions between amino acids
• What determines the primary structure of proteins?

  The sequence of amino acids in a polypeptide
• How does the primary structure of a protein affect its function?

  It determines the protein's shape and function
• What bonds are involved in the secondary structure of proteins?

  Hydrogen bonds between amino acids
• What is the tertiary structure of proteins?

  3D structure formed by R group interactions
• What stabilizes the quaternary structure of proteins?

  Hydrogen bonds, ionic bonds, disulfide bridges