1.5 Respiration Biology N5 Flashcards
what form of energy is found in food
chemical energy
what do all cells require
energy
how is the chemical energy in food releasd
it is released through enzyme controlled reactions called respiration
what is made from the breakdown of glucose in respiration
the glucose is used to make ATP energy
what cellular activities that use the ATP energy
muscle cell contraction, cell division, protein synthesis, active transport of ions or molecules across the cell membrane, transmission of nerve impulses in neurons
how many stages are there in respiration
two stages
describe the 1st stage of respiration
during the first stage one glucose mo0lecule is brokendown into 2 pyruvate molecules which happens in the cytoplasm of the cell and results in making two molecules of ATP to breakdown the pyruvate any further i sdependent on wetrher oxygen is present or absent
explain the processs of the 2nd stage of respiration
pyruvate is brooken down into to carbon dioxide and water when oxygen is present this takes place in the mitochondria of the cell and results in a large number of ATP molecules
what is the word equation for aerobic respiration
gluycose+oxygen>carbondioxide+water+lots of water
describe the relation between energy requirment of a cell and number of mitochondria present in the cell
the higher the energy requirement of the cell the more number of mitochondrioa in the cell and the lower the energy requirment the lower number of mitochondria in the cell
name examples of cells with lots of mitochondria and a high energy requirment
muscle,companion, sperm and nueron cells
what is used to measure rate of respiration
respirometer
explain how a respirometer is used to measure rate of respiration
a respiring organism is placed in the specimen chamber which has a perforated platform which is used to stop the organism touching the soda lime which could harm, it the soda lime is there to remove carbondioxide given out by the organism the starting level of the coloured liquid is noted the organism respires aerobically for a known period of time like an hour for example the organism wiil take up oxygen from the enclosed space causingf the coloured liquid to rise the organism also releases the same volume of carbon dioxide which is absorbed by the soda lime after the one hour is up the new level of coloured liquid is noted the difference imn coloured liquid represents the volume of oxygen taken up by the respiring organism in one hour which is the rate of respirationof the organism in cm cubed per hour
how do you calculate the rate ofrespiration
you divide the difference in level of liquid by the number of minutes
what key variables affect the rate of respiration
temprature glucose concentration oxygen level
how maqny stages are in fermentation
2 stages
what happens during the first stage of fermentation
glucose is brokendown into two molecules of pyruvate this is done in the cytoplasm and the pyruvate is then used to make 2 molecules of ATP
what needs to happen for fermentation to occur
fgermantation occurs only if oxygen is absent
explain the the second stage of fermentation
in the second stage the 2 pyruvate is broken down into lactate because no oxygen is present and occurs in the cytoplasm and no further ATP is made due to no nenergy being released
what is the word equation foer fermentation inn animal cells
glucose>lactate+energy (2xATP)
describe the first stage of fermentation in plant and yeast cells
glucose is broken down into 2 pyruvate which makes 2 ATP
explaimn the second stage of fermentation in plant and yeast cells
in the second stage pyruvate is brokjen down into carbon dioxide and ethanol and no more ATP is made
