Cell Respiration (“Aerobic”)
I always think it is very funny that a lot of people think that respiration is breathing. In fact breathing is only in fact part of respiration. The way to think of it is very simple a “cell” needs to have input to have output. In the case of a human cell it requires oxygen and glucose to go into the cell to then release energy. However, when it releases energy for you to move and do things it also has waste products of water and carbon dioxide gas. Really it is very simple and the cell is really an amazing machine that dis-assembles the molecules which go in like a lego kit and builds new ones. That truly is the most amazing thing in the whole world and basis of life on earth. Nothing to go with “god” but a single cell.
At KS3 you only need to know this in words but why not try and do the proper science….
O2(g) + C6H12O6 (aq) => Energy + H2O + CO2(g)
Also remember that what goes in must go out as no atoms are destroyed in this process. Like a set of balancing scales. So if we balance it then we make the devils own number “666”. So all the bits but the sugar get a 6 then it adds up really nicely….
6O2(g) + C6H12O6 (aq) => 6H2O + 6CO2(g)
Also a lot of people wonder where it all goes, well that is where the lungs and kindneys come in. The CO2(g) comes out via the lungs and the water H2O by the kidneys of by sweating. Otherwise of course you would pop!
Yeast is also a living organism, it respires as it is made from cells. In the respiration process sugar and oxygen is converted to CO2, alcohol and energy for the cell.
The term “respiration” describes any chemical process which releases energy from food. There are two types:
- aerobic respiration needs oxygen
- anaerobic respiration happens when no oxygen is available.
Aerobic respiration releases much more energy from a given amount of food. Anaerobic respiration, or fermentation, releases much less energy. (We only need the aerobic form at KS3)
Anaerobic respiration produces alcohol as a by-product when it happens in plants or fungi such as yeast. Fermentation in bacteria produces lactic acid as a by-product.
Have a look at this experiement where we have aerobic respiration which then moves into anaerobic producing CO2 which is captured…
Culturing a Microbe
Micrococcus luteus is a bacterium that belongs to the family Micrococcaceae. M. luteus is found in soil, dust, water and air, and as part of the normal flora of the mammalian skin. The bacterium also colonizes the human mouth and upper respiratory tract. It was discovered by Sir Alexander Fleming before he discovered Penicillin in 1928.
M. luteus is considered a contaminant in sick patients, is resistant to reduced water potential and can tolerate drying and high salt concentrations without forming spores, probably by slowing of major metabolic processes and induction of unique genes.
M luteus forms bright yellow colonies on nutrient agar and is easy to study in the lab…