Why human need oxygen to live?

Question

Why human need oxygen to live?

Answer 1

It has to do with the way that our cells make energy.  We use glycolysis, which turns basically all starches into pure sugar, and then 'cleaves' the electron bonds to harvest thier energy.

Heres's an easy way to visualize it.  Plants use carbon dioxide and water (along with sunlight) to create sugars:

6 CO2+ 12 H2O=C6H12O6 + 6 O2 + 6 H2O

This equation says that plants use 6 carbon dioxide molecules, and 12 water molecules to create a glucose molecule, 6 oxygen molecules and 6 water molecules.

Humans basically use the reverse process.  We break down the sugar molecule.  In the process of doing this, CO2 is formed and we use the energy from the sunlight that the plants 'harvested'.

Since the reverse process needs oxygen and water in order to work, humans must take in oxygen and water in order to survive.  That's why water is one of the most basic of human needs.  We can go for days or weeks without food, but we must drink water so that our body can produce energy.

Answer 2

humans are eukaryotes that carry out aerobic respiration.

without oxygen gas, we cannot synthesize sufficient ATP to live.  The krebs (citric acid) cycle is important, but that is not why oxygen is important.  the krebs cycle is just the breakdown of sugar into some ATP and NAD/FAD molecules.  Oxygen is the final electron acceptor in the electron transport chain, which is an often overlooked part of energy synthesis/metabolism because it is wrongly seen as part of the krebs cycle.

Answer 3

oxygen is of paramount importance to humans.

deoxygenated blood in the body needs to be oxygenated through the process of diffusion in the aveoli. oxygen is def. needed to make this happen otherwise, blood in the body could become toxic.

cells also need oxygen especially an organelle called mitochondria. they produce energy using aerobic respiration. this energy enables you go about your daily life. without this energy your body would be force to produce energy through anerobic respiration which can be very uncomfortable in the sense that lactic acid would be produced which would build up in your muscles making you sore all over.

i can go on and on but i think you get my point

Answer 4

Respiration is the process of using oxygen as the terminal electron acceptor ( in the electron transport chain ) during energy production.The two processes are coupled ( oxidative phosphorylation) so that the NADHs and FADH2s produced in the Kebs Cycle ( Krebs produces NO ATP, only GTP) and by the malate/ aspartate and glycerol phosphate shuttles are oxidized by the ETC to produce ATP at three places in the step-down process and produce water from reduction of oxygen. If the oxygen is prevented from accepting the reducing equivalwents from the ETC the cell dies ( cyanide , CO , azide block the terminal cytochrome cytochrome oxidase and prevent transfer of electrons to oxygen ).  Oxygen exists in ground state as a diradical..thus making it amenable to reduction, unlike N2 ( nitrogen can be "fixed " but VERY VERY energy expensive )

Answer 5

A little thing called the Kreb's cycle, I believe.

Answer 6

Because humans CANNOT live without Oxygen.

Answer 7

hi

Answer 8

Oxygen is needed in the last step of aerobic respiratioin which produces all the energy we need in the form of ATP. Without this energy which is needed to drive our life processes we could not function.

Answer 9

Oxygen is one of the various ways our body had figured out to extract energy from out surroundings. Food is another way, which provides raw materials that the body uses to make, repair and replace out cells as needed. In order for the body to work with these raw materials, it will need a different kind of energy that comes from oxygen.  When we inhale the oxygen in the air, it is absorbed  by our bodies. Molecules inside of our bodies  will help carry it to the cells, along with the raw materials it will produce the energy necessary for our bodies to performe the everyday functions .

Answer 10

simple and easy

oxygen is the substrate for oxidative phosphorylation..

where 02 + H+ --> H2O  this is not a proper equation but just a rough idea..

before that O2 need to receive electrons from electrons tranport chain..just read about oxidative phsphorylation and u will know why we need oxygen..