6C Homeostasis Basics Flashcards
Define homeostasis
Maintaining a constant stable internal environment
What happens if body temperature is too high
Enzymes may become denatured
Molecules vibrate too much which breaks the hydrogen bonds and it no longer works as a catalyst
What happens if body temperature is too low
Enzyme activity is reduced slowing the rate of metabolic reactions
What happens at optimum temperature
Enzyme activity is at it’s highest
What’s happens if blood ph is too high or too low
Enzymes become denatured
Hydrogen bonds are broken that change the shape of the enzymes active site changes shape so the enzyme no longer acts as a catalyst
What happens at optimum ph
Highest rate of reaction
What happens if blood glucose concentration is too high
Water potential of the blood is reduced to a point where water molecules diffuse out of the cells by osmosis this can cause cells to shrivel up and die
What happens if blood glucose is too low
Cells are unable to carry out normal activities because there isn’t enough glucose for respiration to provide energy
What do homeostatic systems involve
Receptor a communication system and effectors
What do receptors detect
When a level is too high or too low and the information is communicated by the nervous or hormonal system to effectors
What does negative feedback do
Keeps things around the normal level
Why does negative feedback only work within certain limits
If the change is too big then the effectors may not be able to counteract it
Why does multiple feedback systems give more control
Gives you more control over changes in your internal environment
It means you can actively increase and a level so it returns to normal
What would happen if you only had one negative feedback system
It would only turn it on or off
What does a positive feedback system do
Amplifies a change
The effectors response to further increase away from the normal
Positive feedback is used to rapidly activate something
How does the formation of platelets involve positive feedback
Platelets become activated and release a chemical this triggers more platelets to be activated
Platelets very quickly form a blood clot at the injury site
This ends in negative feedback when the body detects a platelets has been formed
How does hypothermia involve positive feedback
Hypothermia- low body temperature
It happens when heat is lost faster than its produced
As the body falls the brain doesn’t work properly and shivering stops this makes body temp fall even more
Positive feedback takes the body temperature further away from the normal level and it continues to decrease unless action is taken
