topic 2- organisation

• What is a tissue?

  A group of specialized cells with similar functions
• What are organs formed from?

  Different tissues working together
• What is the function of the stomach?

  To produce digestive juices and acids
• What are organ systems?

  Groups of organs working together
• What organ system is the stomach part of?

  The digestive system
• What is the main function of the digestive system?

  To break down food for absorption
• What do glands in the digestive system produce?

  Digestive juices containing enzymes
• What is the role of hydrochloric acid in the stomach?

  To kill bacteria and optimize pH
• Where are soluble molecules absorbed in the digestive system?

  The small intestine
• What does the liver produce for digestion?

  Bile
• What is the function of bile?

  To emulsify fats and neutralize acid
• What does the large intestine absorb?

  Water from undigested food
• What is the role of enzymes?

  To increase the rate of reactions
• What are enzymes made of?

  Protein molecules
• Why is the shape of an enzyme important?

  It determines the enzyme's function
• What is an active site?

  The region where substrate binds
• What is the Lock and Key Hypothesis?

  Substrate shape fits the active site
• What happens when enzymes are denatured?

  Their active site changes shape
• What is the optimum temperature for most enzymes?

  Around 37 degrees Celsius
• What happens to enzyme activity above optimum temperature?

  It rapidly decreases and stops
• What is the optimum pH for most enzymes?

  7
• What happens if the pH is too high or low for enzymes?

  The active site shape changes
• What do carbohydrases convert?

  Carbohydrates into simple sugars
• Where is amylase produced?

  Salivary glands, pancreas, small intestine
• What do proteases convert?

  Proteins into amino acids
• What do lipases convert?

  Lipids into fatty acids and glycerol
• Where are lipases produced?

  Pancreas and small intestine
• What happens to soluble glucose and amino acids?

  They enter the bloodstream for use
• What is Benedict's test used for?

  To test for sugars
• What color does Benedict's test turn for sugars?

  Brick red
• What is the iodine test used for?

  To test for starch
• What color does the iodine test turn for starch?

  Blue-black
• What is the Biuret test used for?

  To test for proteins
• What color does the Biuret test turn for proteins?

  Purple
• What is the emulsion test used for?

  To test for lipids
• What happens in the emulsion test if lipids are present?

  A cloudy layer forms
• What is the Sudan III test used for?

  To test for lipids
• What happens in the Sudan III test if lipids are present?

  A red layer forms on top
• Where is bile produced?

  In the liver
• What are the two roles of bile?

  Neutralize acid and emulsify fats