Homeostasis
Cards (14)
- homeostasis-human body cells function most efficiently in optimum conditions
- External changes such as missing a meal ,sunbathing, not drinking, or exercising can all change the internal conditions in which cells work
- Changes in condition either increase or decrease one or more of the following conditions:water levels ,blood glucose concentratio or body temperature
- If body temperature decreases Enzymes are less active.this decreases the rate of many cell reactions,while the diffusion of the substance into and out of cells occurs more slowly
- If water levels increase or decrease,cells gain or loose water by osmosis so they swell or shrink and may change shape
- If blood glucose concentration falls,less glucose is available for respiration, so less energy is available for cell activities such as active transport
- Maintaining optimal internal conditions is called homeostasis and is achieved automatically by variety of control systems
- Organisms need energy for growth homeostasis and muscle contractions
- Aerobic respirationC6H12O6+602———-6co2+6h2o+(energy)glucose+oxygen—-carbon dioxide+water
- Because humans are living in a changing environment we must regulate our bodies internal conditions to make our enzymes and cells funcrion well
- denaturing
- if conditions are not optimal then out enzymes can denature(change shape)
- this reduces their ability to catalyse metabolic reactions (chemical reactions in organisms)
- conditions That must be regulated are
- urea concentration
- internal body temperature
- carbon dioxide levels
- blood sugar levels
- water levels
- bodies negative Feedback loop
- an internal condition change
- chabeg detected by the receptors
- correct mechanisms activated
- internal conditions back to normal
- correct mechanisms deactivate
- Positive feed back is opposite to the negative feedback loop.it makes a small change even bigger.for example the body releasing the hormone oxytocin which increase the number of contractions during child birth