Triple digestive System Flashcards
(22 cards)
Physical digestion involves…
The mouth chewing and the stomach churning to break down foods and increase the SA to make it easier to digest.
Chemical digestion…
Performed by enzymes, which are biological catalysts and large proteins. The catalyse a specific reaction by having the correct shaped active site for a specific substrate. The enzymes also have an optimum temp and pH.
What happens when an enzyme goes past it’s optimum pH or temp
It becomes denatured (unravels and the active site changes shape) and is not fit for purpose.
What is a lock and key diagram
A simplified model of enzyme action
What is the induced fit model
When the active site of an enzyme changes slightly as the substrate binds to it, creating a tighter fit.
What is the purpose of digestive enzymes
They covert large food molecules into small food molecules so that they can be absorbed into the bloodstream
What do Carbohydrases do
They break down carbohydrates to simple sugars
What does the carbohydrase, amylase do
It breaks down starch into glucose
What do proteases do
Breaks down proteins to amino acids
What do lipases do
They break down lipids (fats) to glycerol and fatty acids
What is a dependent variable
What changes
What is the independent variable
What is measurable
What are controlled variables
What is kept the same
How to improve an experiment’s accuracy
Calculate the mean
Take results in more frequently
What is the uncontrolled variable in an experiment
Something that is not regulated or measured
What is the equation for the rate of reaction
Rate of reaction = Change in mass of reactant or product / time
What is Bile
It is made in the liver and stored in the gallbladder.
It is an alkaline and neutralises the hydrochloric acid in the stomach.
It emulsifies lipids/fats making them into small droplets which increases surface area
The alkaline conditions and large surface area increase the rate of fat digestion by lipase.
How is the small intestine adapted for its role of absorption.
Very long, villi, microvilli: provide a large surface area
One cell thick lining: short distance for absorption by diffusion / active transport
Good blood supply: maintains a steep concentration gradient
How does digestion relate to respiration
The products of digestion are used to build new carbohydrates, lipids and proteins.
Some glucose is used in respiration
What is the optimum pH of an enzyme
7/8
What happens to the products of digestion once they are absorbed into the blood
Glucose - respiration
Fatty acids and glycerol - synthesise new lipids
Amino acids - synthesise proteins
What is the optimum temp for an enzyme
40 degrees celsius
