b3 Flashcards
Define cell
Basic unit of living things.
Define tissue
Groups of similar cells performing the same function.
Define organ
Group of tissues performing the same function.
Define organ system
Groups of organs performing the same function.
List the three types of tissue
Muscular, glandular and epithelial.
Describe the role of bile
Neutralises stomach acid and breaks fats down into droplets.
Name the organ where bile is produced
Liver.
Name the organs involved in digestion
Mouth, oesophagus, stomach, liver, small intestine, large intestine, anus.
Give the function of the small intestine
Reabsorbs glucose from digested food.
List the adaptations of the small intestine
Lots of microvilli, good blood supply, thin walls, lots of mitochondria.
Name the substance the stomach contains
Hydrochloric acid (pH 3).
Name the part of the digestive system responsible for reabsorbing water
Large intestine.
Describe the test for starch
Iodine solution. It turns dark blue/black.
Describe the test for simple sugars (glucose)
Benedict’s solution. It turns brick red when heated.
Describe the test for protein
Biuret solution. It turns purple.
Describe the test for Lipids (fats)
Ethanol - milky emulsion is formed.
What are proteins broken down into?
Amino acids.
What are carbohydrates broken into?
Glucose.
What are lipids broken down into?
Glycerol and fatty acids.
Define enzyme
Biological catalyst (speeds up reactions).
Name the three types of digestive enzyme
Amylase (carbohydrase), proteases, lipases.
Where is Amylase produced?
Mouth, pancreas, small intestine.
Where are protease enzymes produced?
Stomach, pancreas, small intestine.
Where are lipase enzymes produced?
Pancreas, small intestine.
Describe what happens to an enzyme when the temperature is too hot.
It denatures.
Describe how the enzyme changes when it denatures
The active site changes shape irreversibly. The substrate no longer fits. The enzyme won’t work.
Describe the lock and key mechanism for enzyme action
The active site of each enzyme is specific to one substrate.
