Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
What is homeostasis? |
The maintenance of the internal environment in a constant state within an organism despite external changes |
|
|
Why is homeostasis important? |
Organisms can only function it internal conditions are kept within a narrow range |
|
|
Why is it important to keep body temperature and blood pH constant? |
To prevent enzymes from denaturing |
|
|
Why is it important to maintain the right blood glucose concentration? |
Cells need glucose for respiration to produce ATP. Glucose level also affects water potential of the blood |
|
|
What is pH? |
The concentration of H+ ions in the environment |
|
|
What is the equation used to calculate pH? |
pH= -log10 [H+] |
|
|
What is H+? |
The concentration of H+ in a solution in moldm-3 |
|
|
What happens when blood glucose concentration is too high?
|
Water potential of the blood is reduced so water molecules would move out of the blood by osmosis. This can cause crenation |
|
|
What happens if blood glucose concentration is too low? |
Cells can't carry out normal activities because there isn't enough glucose for respiration to produce ATP |
|
|
What is negative feedback? |
A process that brings about a reversal of any change in conditions |
|
|
What does negative feedback ensure? |
It ensures that an optimum steady state can be maintained, as internal conditions return to normal |
|
|
What happens once normal conditions are restored? |
The response is inhibited |
|
|
What does homeostasis involve? |
Multiple negative feedback mechanisms for each thing being controlled |
|
|
Why is this? |
It gives more control over conditions. One would be slower and give less control |
|
|
What is positive feedback? |
The process that increases any change detected by receptors. It doesn't lead to homeostasis because it doesn't keep the internal environment constant |
|
|
What is positive feedback used for? |
To rapidly activate processes in the body |
|
|
When can positive feedback occur? |
When there's been a breakdown of homeostatic mechanisms |
