Homeostasis Basics

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A level Biology (5.1.1 Communication and Homeostasis) Flashcards on Homeostasis Basics, created by Yinka F on 14/02/2018.
Yinka F
Flashcards by Yinka F, updated more than 1 year ago
Yinka F
Created by Yinka F almost 7 years ago
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What is homeostasis? The maintenance of a constant internal environment. It involves control systems that keep your internal environment roughly constant (within certain limits)
What happens when body temperature goes above a certain level? The vibrations caused by the increased kinetic energy breaks some of the hydrogen bonds that hold proteins in its 3D shape - the proteins denature
What happens when body temperature falls below a certain level? The rate of metabolic reactions slow down
What is a negative feedback mechanism? A negative feedback mechanism is a mechanism that restores a level to normal
Name 3 components that are involved in homeostatic systems Receptors A communication system Effectors
TRUE OR FALSE: Negative feedback only works within certain limits TRUE If the change is too big then the effectors may not be able to counteract it
Outline the negative feedback loop
What is a positive feedback mechanism? A positive feedback mechanism is a mechanism that amplifies a change away from the normal level
TRUE OR FALSE: Both positive and negative feedback mechanisms are involved in homeostasis FALSE Positive feedback is NOT involved in homeostasis because it doesn't keep the internal environment constant. Instead, it is useful to rapidly activate processes in the body
Give an example of a positive feedback mechanism in the body The formation of a blood clot - platelets become activated and release a chemical, triggering more platelets to be activated, and so on
Outline the positive feedback loop
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