Biology Digestive System Flashcards
(32 cards)
What is a tissue?
collection of similar cells working together to perform a function.
What is an organ?
collection of similar tissues working together to perform a function.
What is an organ system?
collection of organs working together to perform a function.
How do you calculate rate for an enzyme reaction?
1/time OR 100/time
What do enzymes do?
Make large molecules, break down large molecules and turn one molecule into another.
How do enzymes work?
Enzymes have an active site that is specific to only one substrate. When the substrate joins the enzyme, they become known as the enzyme substrate complex. After the reaction, the enzyme remains unchanged, and releases a product that is different from the original substrate.
What does amylase do?
Breaks starch into glucose.
What does protease do?
Breaks protein into amino acids.
What does lipase do?
Breaks fat/lipids into fatty acids and glycerol.
What is the test for starch?
Iodine turns black.
What is the test for sugars?
Bennedict’s solution turns red when heated.
What is the test for protein?
Biurettes solution turns purple.
What is the test for lipids?
Ethanol turns cloudy.
What is the meaning of denatured?
When an enzymes active site has changed shape and is no longer specific to the substrate.
How is the small intestine adapted for its function?
The small intestine is lined with villi, finger like protrusions which provide a large surface area to volume ratio for diffusion. The villi lining is one cell thick, providing a short diffusion distance. The villi have a good blood supply to maintain the concentration gradient.
What is the role of bile in the digestive system?
Bile neutralises stomach acid in the small intestine and emulsifies fats, making them easier to break down.
How does temperature affect enzyme activity?
As temperature increases enzyme activity increases, until optimum temperature is reached.
After optimum temperature enzymes become denatured and activity decreases.
How does pH affect enzyme activity?
Enzymes have an optimum pH, where enzyme activity is highest. If the pH becomes more acidic or alkaline, activity decreases as the enzymes become denatured.
How does concentration of the enzyme affect enzyme activity?
The higher the enzyme concentration, the higher the activity, until substrate concentration becomes the limiting factor and activity stays the same.
How does the concentration of the substrate affect enzyme activity?
The higher the substrate concentration, the higher the activity, until enzyme concentration becomes the limiting factor and activity stays the same.
What is the purpose of the mouth?
The smell of food triggers salivary glands to secrete saliva that contains amylase, breaking down starch. There is also mechanical digestion.
What is the purpose of the oesophagus?
Food is pushed by a series of muscular contractions to the stomach.
What is the purpose of the stomach?
Walls of the stomach contract to churn the food and break it into smaller pieces. It produces protease to break down protein and has hydrochloric acid to kill bacteria.
What is the purpose of the gall bladder?
Stores excess bile before it is released into the mall intestine.
