enzymes and digestion

• What is the structure of epithelial tissue?

  Dense layer of many arranged cells
• What is the function of epithelial tissue?

  To secrete a protective layer for organs
• What type of muscle is described as long and thin?

  Columnar membrane muscle
• What do the intracellular spaces in muscle tissue indicate?

  Arrangement of muscle fibers
• How does muscle tissue change shape as needed?

  By altering its arrangement of cells
• What is the characteristic of the layer of cells mentioned?

  Very dense and vascular
• What do elongated fibers in tissue contribute to?

  Making up the basement-like area
• What is the role of the sheath made around cells?

  To provide structural support
• How often are muscles lined in the described tissue?

  Every 3 or direction
• What is the significance of lining as outside of organs?

  To protect and support organ structure
• Why do we eat food?

  To gain energy and materials for growth
• What is digestion?

  • Breakdown of large, insoluble food molecules
  • Converts them into small, soluble molecules
  • Absorbed into the bloodstream
• Where are soluble products of digestion transported?

  To body cells in the bloodstream
• What are the two types of digestion?

  • Physical digestion
  • Grinding action of teeth
  • Churning action of stomach
  • Chemical digestion
  • Involves digestive enzymes and bile
• What is the role of amylase?

  Breaks down starch into simple sugars
• What is peristalsis?

  Waves of muscle contraction moving food
• What does hydrochloric acid do in the stomach?

  Kills bacteria and aids enzyme function
• What is the function of bile?

  Neutralizes stomach acid and emulsifies fats
• Where is bile produced?

  In the liver
• What is the role of the pancreas in digestion?

  Produces digestive enzymes like lipase
• What happens in the small intestine?

  • Digestion occurs in the first 30 cm (duodenum)
  • Absorption takes place in the rest of the small intestine
  • Villi increase surface area for absorption
• What is the main function of the large intestine?

  Absorbs water and forms feces
• What color indicates a positive test for starch?

  Blue-black
• What does Benedict's solution test for?

  Presence of sugars
• What color indicates a positive test for proteins?

  Pink or purple
• What is the structure of carbohydrates?

  Includes sugars and starches
• What are simple sugars?

  Single sugar units like glucose
• What are lipids made of?

  Fatty acids combined with glycerol
• What is the lock and key model in enzymes?

  Substrate fits into the enzyme's active site
• What happens when an enzyme is denatured?

  Its shape changes and it stops working
• What are digestive enzymes and their functions?

  • Carbohydrase (e.g., amylase): Breaks down carbohydrates
  • Protease: Breaks down proteins into amino acids
  • Lipase: Breaks down lipids into fatty acids and glycerol
• What is the optimum temperature for enzyme activity?

  37°C
• What is chyme?

  A watery solution of digested food
• What does emulsification do?

  Increases the surface area of lipids
• Which enzyme digests lipids?

  Lipase
• What happens to large globules of fat in the small intestine?

  They are broken down into smaller droplets by bile
• What is the method for testing starch with iodine?

  1. Add iodine to the sample.
  2. Observe color change.
  3. Blue-black indicates starch presence.
• What is the method for testing sugars with Benedict's solution?

  1. Add Benedict's solution to the sample.
  2. Heat the test tube.
  3. Observe color change: blue to green/red indicates sugar presence.
• What is the method for testing proteins with Biuret solution?

  1. Add Biuret solution to the sample.
  2. Observe color change: light blue to pink/purple indicates protein presence.
• What is the method for testing lipids with ethanol?

  1. Add ethanol to the sample and shake.
  2. Observe: clear to cloudy white indicates lipid presence.