organisation

• What makes up all living things?

  Cells
• What is a tissue?

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

  From different tissues working together
• What do organ systems do?

  Work together to perform a specific function
• What organ system is the stomach part of?

  The digestive system
• What is the 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 the stomach in digestion?

  Produces hydrochloric acid to kill bacteria
• 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 the large intestine?

  Absorbs water from undigested food
• What are enzymes?

  Biological catalysts that speed up reactions
• Why is the shape of an enzyme important?

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

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

  Substrate shape matches the active site shape
• What is the optimum temperature for most enzymes?

  Around 37 degrees Celsius
• What happens to enzymes at high temperatures?

  They become denatured and stop working
• What is the optimum pH for most enzymes?

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

  The enzyme becomes denatured
• Why are enzymes vital in the digestive system?

  They break down molecules for absorption
• 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
• Where are lipases produced?

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

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

  Testing for sugars
• What color does iodine turn in the presence of starch?

  Blue-black
• What does the Biuret test indicate?

  The presence of protein
• What happens in the emulsion test for lipids?

  A cloudy layer forms with ethanol
• What are the two roles of bile?

  Neutralizes acid and emulsifies fats
• What is the purpose of the practical involving amylase and starch?

  To investigate the effect of pH on enzyme activity
• What is the equation to calculate the rate of reaction?

  Rate = 1000/time
• What is the heart's role in the circulatory system?

  Pumps blood around the body
• What is a double circulatory system?

  Two circuits for blood flow
• Where does deoxygenated blood flow first in the heart?

  Right atrium
• What happens to blood in the right ventricle?

  It is pumped to the lungs
• What is the function of the left ventricle?

  Pumps oxygenated blood around the body
• What is the role of valves in the heart?

  Prevent blood from flowing backwards
• What controls the natural resting heart rate?

  A group of cells in the right atrium
• What is an artificial pacemaker used for?

  To regulate an irregular heartbeat