homeostasis and cell’s Flashcards
(74 cards)
what is homeostasis
maintenance of a stable internal environment so that your internal environment is kept in a state of dynamic equilibrium
what are factors of homeostasis
temperature regulation, regulations of hormones, maintain blood pressure
why is it important to maintain the right core body termperature and blood ph
temperature and pH affect enzyme activity, and enzymnes control the rate of metabolic reactics
why is it important to maintain the right blood glucose concentration
because cells need glucose for energy and blood glucose concentration affects to water potential of blood
why does the rate of metabolic reactions increase when the temperatures increased
more heat means more kinetic energy, the molecules will move faster, meaning they are more likley to collide with the enzymes active sites.
if the temperature gets too high why does the reaction eventually stop.
the rise in tempertaure makes the enzymes molues vibrate more. If the temperature becomes too high , the vibration brakes some of the hydrogen and ionic bonds which hold the enzyme in its shape. the active site changes shape and the enzyme and substrate no longer fit. enzyme is denatured
if blood ph is too high or low why do reactions eventually stop
enzymes will denature due to the hydrogen and ionic bonds breaking, the active site changes shape and the substrate will no longer fit, the reaction can not occur.
how would you calculate the pH
calculated based on the concentration of hydrogen ions (H+) in the environment
if it is a more acidic environment, does this mean there is a high concentration of H+, or a low concentration
as there is a greater concentration of H+, the lower the pH will be, meaning it is a more acidic environment
why is it bad if blood glucose concentration becomes to high
if it is too high, the water potential of blood is reduced to a point where water molecules diffuse out of cells into the blood via osmosis, this can cause the cells to shrivel up a die.
if blood glucose concentration is too low why are cells unable to carry out normal activities
because there isn’t enough glucose for respiration to provide energy
explain the negative feedback loop
- receptors detect when a level is too high or too low
- the information is communicated via the nervous system or the hormonal system to effectors.
- the effectors respond to counteract the change, bringing the level back to normal
fill in the blank
normal level -> level changes from normal -> receptors detect change -> -> effectors respond -> level brought back to normal
communication via nervous or hormonal system
why do we have multiple negative feedback mechanisms
means you can actively increase or decrease a level so it returns to normal e.g you have feedback mechanisms to reduce your body temperature and also have mechanisms to increase it.
is this feedback loop negative or positive?
normal level -> normal level changes -> receptors detect change -> communication via nervous or hormonal system -> effectors respond -> change amplified
positive feedback loop
what is positive feedback
the mechanism that amplifies a change away from the normal level
when is positive feedback useful
it is useful to rapidly activate processes in the body
blood glucose concentration is monitored by cells in the what
pancreas
the hormonal system controls blood glucose concentration using which two hormones
insulin and glucagon
What is the role of the nucleus
Contains nucleolus which has cell DNA. Directs all metabolic activities
What is the role of the smooth endoplasmic reticulum
Synthesises lipids and steroid hormones
What is the role of the fought endoplasmic reticulum
Studded with ribosome which synthesis proteins
What is the role of the Golgi apparatus
Where proteins are packaged into membrane bound vesicles
What is the role of the mitochondria
Powerhouse of cell. Produce ATP
