Enzymes Flashcards
Which enzyme works best in acidic conditions?
protease or pepsin
What is the optimum temperature for enzymes in the human body?
37 degrees celsius
What type of enzyme is amylase?
Carbohydrase
How does hydrochloric acid in the stomach help digestion?
Provides optimum pH for protease enzymes
Which enzyme breaks down starch?
amylase
Which enzyme works best in alkaline conditions?
lipase
Where do protease enzymes act?
stomach and small intestine
Why are enzymes described as specific?
Each active site has a specific shape that fits only one type of substrate
Where does absorption take place?
small intestine
Where does carbohydrate digestion occur?
mouth and small intestine
What happens when an enzyme is heated up too high?
the active site changes shape so the substrate is no longer able to bind to it - It becomes denatured
Describe how to test for proteins
Add Biuret solution to the sample and it will turn from blue to lilac if protein is present
Describe how to test for glucose
Add benedict’s reagent to the sample and heat/boil it. It will turn from blue to brick red if glucose is present.
Describe how to test for starch
Add iodine solution to sample and it will turn from orange-brown to blue-black if starch is present
Which acid is found in the stomach?
Hydrochloric Acid
Why does increasing temperature increase the rate of enzyme activity?
Enzyme and substrate molecules have more kinetic energy so they move faster and collide more frequently. More enzyme-substrate complexes are formed as a result.
What are the products of fat digestion?
Fatty acids and glycerol
Which enzyme breaks down protein?
protease
Describe 2 roles of bile
- Emulsifies fat creating a larger surface area for lipase enzymes to act. 2. Bile is an alkali so neutralises the acid contents from the stomach providing the optimum pH for lipase
Where does fat (lipid) digestion occur?
small intestine
What provides alkaline conditions in the small intestine?
bile
Where are lipase enzymes produced?
Pancreas and small intestine
Which enzymes breaks down fats?
lipase
where are carbohydrase enzymes, like amylase, produced?
salivary glands, pancreas, small intestine
Where are protease enzymes produced?
Stomach, pancreas, small intestine
Explain the lock and key theory
The substrate (lock) has a complementary shape to the enzyme’s active site (key) so it will bind to it to form an enzyme-substrate complex (lock and key). The substrate is broken down into products which are then released. If the substrate’s shape (lock) isn’t complementary to the enzymes active site (incorrect key), then it doesn’t bind together.
Which organ produces bile?
liver
Describe how the villi in the small intestine are adapted for their function
Many villi/microvilli which provide a large surface area for absorption. They are one cell thick so provide a short diffusion distance. They have a good blood supply which maintains a steep concentration gradient. They contain many mitochondria to provide energy for active transport
Describe how to test for fats
Add ethanol to food sample and mix. Then add it to water and if a white emulsion forms fat is present.
What are the products of starch digestion?
Sugars
What are the products of protein digestion?
amino acids
Which organ stores bile?
gallbladder
Why does digestion occur?
To break large, insoluble molecules into small, soluble ones so they can be absorbed into the bloodstream
