Question

Can someone explain how cellular respiration work in simple words, but giving the same level of understanding?

Answer 1

There is aerobic respiration where oxygen is used as electron acceptor at the end of electron transport chain!! and there is anerobic respiration which uses substrate as electron acceptor at last od ETC

Answer 2

u can search about ETC to learn about cellular Respiration

Answer 3

On a super-basic level think of photosynthesis which is anabolic (building up), cellular respiration undoes photosynthesis and is catabolic (breaking down.) Energy is harvested and stored in the relatively complex high-energy bonds of sugar molecules during photosynthesis and broken down and harnessed to do biological work in the cell and returned to their original simple form during cellular respiration.
Formula as follows....CO2 + H2O + Energy(light) → C6H12O6 + O2 - photosynthesis .C6H12O6 + O2 → CO2 + H2O + Energy - respiration

Answer 4

Unfortunately, there is no real simple way to explain respiration I will do my best to keep this explanation general so if you need more details just let me know.

Cellular respiration is all about converting glucose into another chemical called ATP that can be used to do cellular work. I think of this conversion like walking into the dollar store with a one thousand dollar bill. Lets say I buy five items. I have plenty of money but the cashier probably wont sell me the items because she/he can't make change for $1000. This is glucose it has plenty of energy to do cellular work but the cell can't use it in that form. So just like you could go to a bank and get your $1000 dollar bill broken into smaller bills, cellular respiration is going to break that glucose into smaller units of energy know as ATP. I think of ATP like a rechargeable battery. ATP is a fully charged battery. As it's used it loses energy and becomes a molecule called ADP. This molecule is very similar to ATP but it lacks the potential energy to do work. It's a dead battery. But just like you could put the battery in a charger and make it useful again ADP can be rephosphorylated into ATP. Anyway, respiration happens in 3 phases: Glycolysis, The Krebs or citric acid cycle, and the electron transport chain.

Glycolysis:
This process takes place in the cytoplasm of the cell and literally means to cut glucose. Glucose has 6 carbons so if we cut it in half we should get 2 molecules each with 3 carbons. These molecules are called pyruvate. Now there are roughly 8 chemical intermediates in the process that converts glucose into 2 pyruvate molecules I will only include the most important ones. So, remember our overarching goal is to make ATP but to do this we need to invest some energy. so glycolysis starts with what is usually called an investment phase. I generally think of chemistry like playing with Legos so picture a Lego house...if I want to use the same pieces to build a Lego boat I will have to invest some initial energy into disassembling the Lego house. Glucose is the Lego house and the cell has to invest some energy in its disassembly. The energy investment is 2 ATP molecules and glucose is changed into 2 molecules of G3P. (the Lego boat if you will) Everything that happens after this point is going to release energy. That energy will be in the form of actual ATP and a molecule called NADH. NADH is made when a molecule called NAD+ is reduced. NAD+ is an electron carrier...I think of it as a molecular city bus. NAD+ is a vehicle tat carries high energy electrons from where they were created to where they are going to do work. In this case all NADH travels to the Electron transport chain. So to finish this section up, as 2 G3P are converted to 2 molecules of a chemical called 1,3, biphosphoglycerate and then to 2 molecules of Pyruvate enough energy is released to form 2 NADH (go to ETC) and the four phosphate groups from 1,3, biphosphoglycerate are attached to ADP making 4 ATP. So at this point we have 2 ATP to bank and 2 NADH traveling to the ETC.

Given that it will take me a long time to type out the Krebs and the ETC I will summarize them in terms of inputs and outputs and if you need more details I can include them later.

So the 2 pyruvates made in glycolysis in an environment where Oxygen is present will move into the empty space (matrix) of the mitochondria. Passing through the mitochondrial membrane requires the removal of a CO2 group from pyruvate. This is a partial oxidation (energy released) and just like before the energy released jumps on the bus (NAD+) making NADH which goes to the ETC. At this point, we are left with a small two carbon compound that reacts with a 4 carbon compound to form citric acid which has 6 carbons. This is the beginning of the citric acid cycle. The citric acid cycle is a series of oxidations that release CO2. Once again this means energy is released and it jumps on the buses that will carry it to the ETC where it can be used to do work. The work in this case will be turning ADP into ATP. So after the Krebs /citric acid cycle our two molecules of pyruvate have been turned into 8NADH (travel to ETC) 2 FADH2 (FAD + energy = FADH2) (Travel to ETC) and 2 actual ATP. So remembering that our goal is to make ATP at this point we have only made 4 But the NADH and FADH2 we just made are going to allow us to make much more.

The electron transport chain and ATP synthase are a series of proteins in the mitochondrial membrane. Think of this protein combination as a big machine that assembles ATP by attaching a inorganic phosphate to an ADP(recharging the battery). But just like any machine it needs fuel to power it. This fuel comes in the form of high energy electrons that are being brought to the ETC by our molecular busses NADH and FADH2. Every NADH has approximately enough energy to make 3 ATP and every FADH2 has approximately enough energy to make 2 ATP. These electrons are pulled through the ETC by ever increasing electronegativity until they are given to oxygen (this is the whole reason we need to breath) in the inner membrane space. This I how water is made. The electrons moving through the ETC are releasing energy (electrons moving toward more electronegative atoms lose/release energy) that is used to drag protons into the inner membrane space. This make the inside crowded (concentration gradient) and the protons (H+) start to look for a way to escape the membrane. Their escape is through ATP synthase (enzyme that builds ATP). This proton motive force or, a force created by moving protons is what powers the ATP synthase and finale constructs the ATP we've been trying to make all along. So over all we can make 36-38 ATP. 2 in glycolysis 2 in the Krebs and roughly 34 made from NADH and FADH2 at the ETC.

Hope that helps.