Cellular respiration cycle is a combination of various metabolic processes to derive energy from nutrients or food molecules. All living organisms including bacteria, plants, animals all use cellular respiration processes to produce energy. Here we describe all possible aspects regarding cellular respiration cycle.
In this blog post, we will see the various aspects of cellular respiration.
What Is Cellular Respiration?
Cellular respiration cycle is a combination of some metabolic processes that occurs in living cells, which converts food or nutrients into energy units (ATP) and releases different by-products from it.
Cellular respiration formula
The basic formula of cellular respiration cycle (typical aerobic respiration) is-
Glucose +6 water → 6 carbon dioxide + 6 water + 36-38 ATP
C6H12O6 + 6O2 –> 6CO2 + 6H2O + 36 or 38 ATP
The equation specifies that during cellular respiration (in presence of Oxygen molecule) one Glucose molecule burns with 6 oxygen molecules to produce 36-38 ATP molecules as energy units. The reaction also releases 6 carbon dioxide molecules and 6 water molecules as by- products.
Cellular respiration diagram
From the diagram of cellular respiration we can see that there are 4 major steps through which the required energy of cell is produced cyclically. The first step Glycolysis takes place in cytoplasm of cell and the other steps take place in mitochondrial matrix of cell.
Cellular Respiration Cycle from Wikimedia Commons
Cellular respiration reactants
The main reactant in cellular respiration cycle is Glucose and Oxygen molecules.
In cellular respiration process basically the nutrient or food molecule like carbohydrate, proteins participates in respiration process to produce energy. The main reactant is the oxygen molecule in this process. The oxygen serves as the last electron acceptor molecule during the oxidative phosphorylation process.
Cellular respiration cycle process
Cellular respiration process is combination of various metabolic reactions through which Glucose molecules breaks down.
The cellular respiration process (aerobic) generally undergoes four major steps to generate most of the energy. The steps are including-
Glycolysis
Glycolysis is the first step in the cellular respiration process. In this process 1 Glucose molecule breaks into 2 pyruvic acid or pyruvate molecules. The Glycolysis process occurs in the cytoplasm of a cell.
Ten different reactions are involved to facilitate the process. Enzymes involved in Glycolysis pathway are hexokinase, phosphoglucomutase, phosphofructokinase, aldolase, Triose-phosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, phosphoglycerokinase, phosphoglyceromutase, enolase, pyruvate kinase, etc.
During this process 1 Glucose (6-carbon) molecule breaks into 2 pyruvate molecules (3- carbon), releases 2 ATP and 2 NADH molecules as by-products.
Glucose (C₆H₁₂O₆) → Pyruvate (CH₃COCOOH) + 2 NADH + 2 ATP
Throughout the process oxygen molecules are not necessary, that’s why Glycolysis occurs in both aerobic and anaerobic respiration processes.
This process was discovered by German biochemist Gustav Embden, Otto Meyerhof, and Jakub Karol Parnas and after their names the whole process is known as Embden-Meyerhof-Parnas pathway or EMP pathway.
Acetyl-CoA formation
After the end of the glycolysis pathway the pyruvate converts into acetyl-CoA which later participates in Krebs cycle process.
In this process the pyruvate oxidised to form a 2-carbon acetyl group. After the 2-carbon acetyl group bonds with coenzyme -A and produces Acetyl-CoA.
After Glycolysis the pyruvate enters mitochondria and the acetyl-CoA formation reaction occurs in the matrix of mitochondria.
This acetyl-CoA formation process is very significant in cellular respiration process. As only though this process the pyruvate converts into acetyl-CoA and acetyl-CoA is the only component which can undergoes Krebs cycle procedure.
It is also very significant because due to this process the pyruvate cross the plamsa membrane and travels into the mitochondrial matrix from the cytoplasm of cell.
Krebs cycle
Krebs cycle is the third and most important step in cellular respiration process. It only occurs in an aerobic environment.
In case of anaerobic respiration after Glycolysis the pyruvate directly breaks and produces organic by-products to release energy.
In Krebs cycle process the acetyl-CoA breaks and after several reactions produces 2 carbon dioxide molecules, 1 GTP (or ATP), 1 FADH2 and 3 NADH molecules. At around 8 different enzymes are involved in this process such as,
- Citrate synthase
- Aconitase
- Isocitrate dehydrogenase
- α-ketoglutarate
- Succinyl-CoA synthetase
- Succinate dehydrogenase
- Fumarase
- Malate dehydrogenase
In this process Citric Acid or citrate is produced as the first reaction product. That’s why the cycle is also called the Citric Acid Cycle.
As the citrate has three carboxylic groups (- COOH), the reaction is also known as TCA cycle or Tricarboxylic Acid Cycle.
Electron transport chain
It is the last step of cellular respiration cycle where finally most of the energy releases after electron transfer via membrane proteins in the mitochondrial matrix. The NADH, FADH2 molecules transfer electrons and release energy.
In the aerobic respiration process oxygen molecules act as the last electron acceptor molecule.
It produces 36-38 ATP per glucose molecule. It is also known as oxydetive phosphorylation process. In anaerobic respiration process sulphate, nitrate groups act as electron acceptor molecules and produce less amount of energy.
Cellular respiration cycle types
According to the presence of the Oxygen molecule in the environment we can differentiate cellular respiration types.
There are two types of cellular respiration are found in nature. First one is aerobic respiration process, respiration process in presence of Oxygen molecule. Another one is the anaerobic respiration process, in which oxygen molecules are not necessary.
Types of Cellular Respiration
There are different variants of cellular respiration pathways that allow cells to produce ATP, the energy currency of the cell. This article explains the various types of cellular respiration. The table below summarizes the details of the types of cellular respiration pathways:
| Type of Cellular Respiration | Reactants | Products | ATP Yield | Location |
| Aerobic Respiration | Glucose, Oxygen | Carbon Dioxide, Water, ATP | 36-38 ATP | Mitochondria |
| Anaerobic Respiration | Glucose | Lactic Acid (in animals) or Ethanol and Carbon Dioxide (in plants and yeast), ATP | 2 ATP | Cytoplasm |
| Fermentation | Glucose | Lactic Acid (in animals) or Ethanol and Carbon Dioxide (in plants and yeast), ATP | 2 ATP | Cytoplasm |
Aerobic respiration
Aerobic respiration process is the most common cellular respiration process that occurs in all multicellular living organisms, such as bacteria, fungi, plants, animals, etc.
In this process in the presence of Oxygen molecule the sugar content burns and produces energy for the cell.
The whole process consists of four different steps, such as Glycolysis, Acetyl-CoA formation, Krebs cycle and oxidative phosphorylation.
After completing the whole process along with 36-38 molecules of ATP, 6 carbon dioxide molecules and 6water molecules are produced as end products.
Aerobic respiration process from Wikimedia Commons
Glucose +6 water → 6 carbon dioxide + 6 water + 36-38 ATP
C6H12O6 + 6O2 –> 6CO2 + 6H2O + 36 or 38 ATP
Anaerobic respiration
Anaerobic respiration process mostly occurs in lower groups of organisms body mostly in prokaryotic cells. Anaerobic respiration process is also known as Fermentation process.
In this process in absence of oxygen, carbohydrate or glucose molecules break down and produce small amounts of energy (2ATP) along with some organic by-products.
As it lacks oxygen molecules, inorganic groups like sulfate, nitrate groups serve as electron acceptor and release some energy. In anaerobic respiration only Glycolysis and electron transport chain processes are found.
There is usually two types of anaerobic respiration process is found –
Fermentation: An Anaerobic Process that Occurs in the Absence of Oxygen
Fermentation is a metabolic process which happens in the absence of oxygen. It is an anaerobic pathway which breaks down glucose into smaller molecules.
This creates energy in the form of ATP. It is necessary for organisms unable to do aerobic respiration due to no oxygen.
Glucose is broken down via glycolysis, and this forms pyruvate molecules plus NADH. Without oxygen, the pyruvate molecules convert to things like ethanol or lactic acid, based on the organism.
NADH is then turned back into NAD+ so it may be used again during glycolysis.
Fermentation also happens within mitochondria. These organelles have enzymes and co-factors essential for the metabolic pathway to occur.
There are a few chemical reactions which convert pyruvate and make energy.
Example:
- Humans have used fermentation for thousands of years to make beverages such as beer and wine.
- Yeast cells carry out alcoholic fermentation to make these drinks with unique smells and flavors which are desirable.
- ATP production in cellular respiration transforms glucose into energy one chemical bond at a time.
Lactic acid production
In the first one Glucose molecule breaks and produces pyruvate during the Glycolysis step and after that the pyruvate converts into lactic acid and produces energy.
C6H12O6 → C3H6O3 + energy (2ATP)
Lactic Acid Fermentation from Wikimedia Commons
Alcohol fermentation
In the second type of anaerobic respiration process one Glucose molecule breaks and produces pyruvate during the Glycolysis step and after that the pyruvate converts into ethanol and produces energy along with a carbon dioxide molecule.
C6H12O6 → C2H5OH + CO2 + energy (2ATP)
Alcohol fermentation from Wikimedia Commons
To know more about anaerobic respiration process read our article on 4+ Anaerobic Respiration Examples : Detailed Explanations
Products of Cellular Respiration
Cellular Respiration is a metabolic pathway that involves the breakdown of glucose to produce energy in the form of ATP. In simpler terms, it is the process of converting the energy stored in glucose into a usable form of energy.
The products of Cellular Respiration are the end products obtained after the completion of this process.
The table below showcases the various products of Cellular Respiration:
| Product | Location of Production | Function |
| ATP | Mitochondria | Provides energy to cells |
| Carbon Dioxide | Mitochondria | Waste product in metabolism, removed by the respiratory system |
| Water | Mitochondria | Important for maintaining hydration levels |
| NADH | Cytoplasm/Mitochondria | Acts as an electron carrier for oxidative phosphorylation and ATP synthesis |
| FADH2 | Mitochondria | Acts as an electron carrier for oxidative phosphorylation and ATP synthesis |
| Pyruvate | Cytoplasm | Acts as a reactant in the Citric Acid Cycle for ATP production, and forms lactate in fermentation |
| Lactate | Cytoplasm | Waste product in fermentation, removed by the liver and kidneys |
ATP Molecules
The cells’ energy currency is synthesized through a process called Cellular Respiration. This produces Adenosine triphosphate (ATP) molecules.
ATP works to store and transfer energy in all living organisms by releasing one phosphate group via hydrolysis, creating adenosine diphosphate (ADP).
ATP molecules are found everywhere in the cell, vital for metabolic processes such as muscle contractions, nerve impulse transmission, and chemical reactions.
The human body needs millions of ATP molecules each second, so active re-synthesis is essential.
Carbohydrates and fats break down during cellular respiration, forming ATP molecules.
Glucose goes through glycolysis to create pyruvate, which goes through the Krebs cycle to generate electronic carriers that power oxidative phosphorylation, producing ATP.
Function Of NADH and FADH2 In Cellular Respiration
NADH is made during glycolysis and FADH2 is generated during the Krebs cycle.
Both molecules help create ATP in the electron transport chain, which is necessary for cellular function.
| Product | Location | Function |
| NADH | Made during glycolysis | Helps create ATP in the electron transport chain |
| FADH2 | Generated during the Krebs cycle | Helps create ATP in the electron transport chain |
Function Of CO2 and H2O In Cellular Respiration
Cellular respiration yields carbon dioxide (CO2) and water (H2O) as its end products.
Glucose is broken down to create ATP, which is then utilized for energy in cell processes. Thus, CO2 and H2O are released as waste.
- CO2 is an odorless gas, heavier than air, with a sour taste. It is formed when glucose is oxidized in cell mitochondria during respiration.
- H2O, on the other hand, is a colorless liquid with vital roles in the body – such as temperature regulation and waste removal.
- Interestingly, photosynthesis works in reverse of cellular respiration. Plants take in CO2 and H2O, and produce glucose and oxygen.
How does cellular respiration work?
The cellular respiration cycle is a very complicated mechanism through which our body gets required energy from the food we take.
The process is started when a living organism takes some food. The nutrients from that food are broken into smaller units like Glucose and through blood flow that reaches each and every cell of the body.
After that when the organism breathes and takes oxygen, the oxygenated blood also reaches each and every cell of the body and the cellular respiration process starts.
When starting in the presence of Oxygen the cell breaks the Glucose and try to produce energy with the help of several enzymes involved in the process.
The Glucose molecule undergoes a Glycolysis pathway that releases a small amount of energy and converts into pyruvate in the cytoplasm of the cell.
The pyruvate then transfers into the mitochondrial matrix and is oxidized to form acetyl-CoA.
Next it undergoes Krebs cycle and after oxidative phosphorylation processes large amounts of energy releases. This energy will be used for every function of the body and that’s how the cellular respiration process works.
How long does cellular respiration take in plants?
As cellular respiration is a very quick process but every kind of cell completes respiration in different times.
A plant cell respires 24 hours a day because the organism needs energy constantly. According to the cell type a basic cell typically completes a cellular respiration cycle within a milliseconds.
How long does cellular respiration take in humans?
The cellular respiration cycle is a very quick process but every kind of cell completes respiration in different times.
A cell respire 24 hours a day. According to the cell type a cell produces 10 million ATP units per second.
The respiration process depends strictly on the cell type. For example , a muscle cell completes the cellular respiration process more rapidly than a liver cell.
How long does one cycle of cellular respiration take?
How long one cycle of cellular respiration takes completely depends on the type of that particular cell.
Typically a cell completes one cycle of cellular respiration within a millisecond and produces energy.
Cellular respiration cycle product
The main function of the cellular respiration cycle is to produce energy from nutrients. So in both of the cellular respiration processes energy molecules are released.
In the aerobic respiration process along with energy molecules 6 carbon dioxide molecules and 6 water molecules are produced as end products.
C6 H12O6 + 6O2 –> 6CO2 + 6H2O + energy (36 or 38 ATP)
In anaerobic respiration lactic acid production process along with energy lactic acid molecules are produced as the end products of the reaction.
C6 H12O6 → C3H6O3 + energy (2ATP)
In the alcohol fermentation process in absence of oxygen molecules along with energy ethanol and carbon dioxide molecules are produced as end products of reaction.
C6 H12O6 → C2 H5OH + CO2 + energy (2ATP)
To know more about fermentation read our article on Is Fermentation Anaerobic Respiration:What,Why,Detailed Facts
As a whole we can say that cellular respiration process is an most important metabolic process for the energy of living organisms.
Only through this process a cell breaks nutrients and converts it into energy units ATP.
Here we discuss all possible aspects regarding cellular respiration process including steps, types and many more. The role of cellular respiration process in generating energy is immense.
Cellular respiration is a process of breaking down glucose into energy. It involves many reactions in living cells, producing ATP (adenosine triphosphate). This energy currency is essential for organisms’ survival and functioning.
The cycle of cellular respiration has two paths: aerobic and anaerobic. Aerobic occurs with oxygen, with glycolysis, citric acid cycle, and oxidative phosphorylation. Anaerobic happens without oxygen.
Glycolysis breaks down a glucose molecule into pyruvate molecules, which then get converted to acetyl-CoA.
The citric acid cycle in the mitochondrion’s matrix releases electrons. These electrons produce ATP through oxidative phosphorylation.
Fermentation also produces ATP in the absence of oxygen. It happens when an external electron acceptor isn’t available at the end of the electron-transport chain.
To optimize cellular respiration, it’s key to balance glucose and enzymes like NAD+ and FAD+. Exercise boosts mitochondrial biogenesis, increasing NAD+ levels.
The Metabolic Pathway of Cellular Respiration
To understand the process of harnessing energy from food, we need to explore the metabolic pathway involved in cellular respiration.
Explanation
The Metabolic Pathway of Cellular Respiration can be explained through a table that highlights its different stages.
It is essential to note that during aerobic respiration, glucose undergoes glycolysis, pyruvate oxidation, citric acid cycle, and oxidative phosphorylation, which produces a significant amount of ATP.
In contrast, in the absence of oxygen, anaerobic respiration takes place, and pyruvate is converted to products such as lactic acid and ethanol.
Glycolysis: The First Stage of Cellular Respiration
Glycolysis is the primary mode of ATP production and it takes place in the cytoplasm outside of mitochondria.
This process starts with one glucose molecule being broken down into two pyruvate molecules.
Ten enzymes trigger multiple reactions to break down each glucose molecule, plus, it creates 2 ATP, 2 NADH+ and 2 pyruvic acid molecules. Subsequently, these end-products follow more pathways to yield CO2 and H2O.
Pyruvate Oxidation: The Second Stage of Cellular Respiration
Pyruvate molecules are oxidized in the second phase of cellular respiration. This produces acetyl CoA and generates NADH.
Conversion of Pyruvate to Acetyl-CoA
This section talks about transforming Pyruvate to Acetyl-CoA, a key part of cellular respiration.
The transformation takes place in the mitochondria, with an enzyme called Pyruvate Dehydrogenase.
Pyruvate is decarboxylated and oxidized, and its power is stored in Acetyl-CoA. This pathway’s good function helps create ATP and keep metabolic balance.
See the table for the steps:
| Substrate | Reaction | Coenzymes | Products |
| Pyruvate | DecarboxylationOxidation | NAD+CoA-SHTPPLipoamide | Acetyl-CoACO2NADH+H+ |
Pyruvate Dehydrogenase needs things like Thiting point is that glucose from food gets changed into energy quickly.
For better functioning, eat foods with Vitamin B1 and B2. Intense activities or fasting can cause Pyruvate Dehydrogenase to slow or stop, so try to avoid those situations to maintain healthy cellular metabolism.
- Acetyl CoA flows into the Citric Acid Cycle, creating more ATP through oxidative phosphorylation.
- This step is key as it extracts energy from glucose that was unused during glycolysis.
- By taking electrons from NAD+, pyruvate oxidation also reduces NAD+ levels to create NADH.
- Interestingly, studies show that regulating pyruvate oxidation is a top priority in cancer metabolic reprogramming.
- Cancer cells may use more pyruvate to fuel rapid growth, which underscores its importance in cellular functions.
The Citric Acid Cycle: The Third Stage of Cellular Respiration
The citric acid cycle is a crucial metabolic pathway in the third stage of cellular respiration.
This pathway involves many chemical reactions that create energy-rich molecules, such as NADH and FADH2.
Plus, it also releases CO2 as waste. This cycle is located in the mitochondria of eukaryotic cells and comes after glycolysis and before oxidative phosphorylation.
The cycle starts when acetyl-coA enters, formed from pyruvate by decarboxylation. This reaction gives off carbon dioxide and energy-rich NADH.
It’s important to understand how this pathway helps living organisms survive. Knowing the details can help us learn how our bodies generate energy from food.
Oxidative Phosphorylation: The Fourth Stage of Cellular Respiration
Oxidative phosphorylation is the last stage of cellular respiration. It uses energy from the NADH and FADH2 electron carriers to make ATP, the cell’s energy currency.
This metabolic pathway takes place in the inner mitochondrial membrane. The flow of electrons through complexes pumps hydrogen ions into the space between the membranes, creating an electrochemical gradient for ATP synthesis.
Some bacteria and archaea use different electron acceptors and donors, such as iron and sulfur compounds instead of oxygen. This shows the variety of metabolic pathways in different organisms.
It is vital to understand oxidative phosphorylation. It affects cellular function and can be changed by factors like disease or toxins.
Knowing this process makes it possible to create strategies to treat mitochondrial diseases.
To understand respiration and its pathways, scientists must continue researching and learning.
Electron Transport Chain: Part of Oxidative Phosphorylation
Electron transport chain is a key part of oxidative phosphorylation. This metabolic process makes ATP in living cells and takes place in the mitochondria. It is the last step in the series of reactions.
The second shows their purpose, such as transferring electrons or pumping protons. The third notes whether they create an electrochemical gradient or release energy.
Moreover, chemiosmosis works with electron transport chains to create the gradient.
This powers ATP synthesis and needs both oxidizing and reducing agents, with oxygen as the final electron acceptor and water as a byproduct.
Citric Acid Cycle
The Cycle of Tricarboxylic Acid (TCA) is a series of chemical reactions used for respiration by most aerobic organisms. Acetyl-CoA produces citrate, which produces ATP through various other intermediate products.
The Citric Acid Cycle is complicated, as it involves various steps.
A table outlines the steps involved:
| Steps |
| Condensation |
| Isomerization |
| Oxidation and Decarboxylation |
| Substrate-level Phosphorylation |
| Dehydrogenation |
| Hydration |
| Oxidation and Decarboxylation |
- This cycle’s main purpose is the production of ATP. It’s also critical for many cell processes, such as gluconeogenesis, amino acid synthesis, and heme biosynthesis.
- Glucose undergoes respiration twice to produce pyruvate and again to produce ATP.
- Redox reactions occur in the cycle, enabling organisms to extract energy from organic molecules gradually.
- If oxygen is absent, the cycle halts, as it depends on oxygen as an electron acceptor.
Electron Transport Chain and ATP Synthesis
Cellular respiration involves energy release and ATP synthesis through Oxidative Phosphorylation.
To understand Electron Transport Chain and ATP Synthesis, we must consider regulating factors. Some of these are:
| Proton Gradient | A difference in electric potential caused by proton concentration differences across the inner mitochondrial membrane. |
| Cytochromes | Proteins with iron-containing heme complex used to transfer electrons in the electron transport chain. |
| NADH and FADH2 | Molecules involved in transferring electrons from citric acid cycle to electron transport chain. |
| ATP Synthase | Enzymes are used to generate energy by converting ADP + Pi into ATP. |
ATP Production in Cellular Respiration
Cellular respiration is a metabolic pathway that results in the production of ATP from glucose.
ATP production in cellular respiration occurs through a series of steps that involve the conversion of glucose and other reactants into ATP molecules.
The following table shows the ATP Production in Cellular Respiration:
| Stage | Process | Location | ATP Produced |
| Glycolysis | Partial oxidation of glucose to pyruvate | Cytoplasm | 2 ATP |
| Pyruvate oxidation | Conversion of pyruvate to acetyl CoA | Mitochondrial matrix | 0 ATP |
| Krebs cycle | Series of redox reactions | Mitochondrial matrix | 2 ATP |
| Electron transport chain | Series of redox reactions involving electron carriers | Inner mitochondrial membrane | 28-32 ATP |
| Fermentation | Anaerobic process of ATP production from glucose | Cytoplasm | 2 ATP |
ATP Synthase: The Key Enzyme Involved in ATP Production
The enzyme ‘ATP Synthase‘ is key in generating ATP for cellular respiration. It’s part of the process called oxidative phosphorylation. It helps convert ADP to ATP with the H+ protons released.
ATP Synthase has a special structure that changes as it creates ATP. It also controls the energy balance within cells by regulating the proton gradient across the inner mitochondrial membrane.
End Products of Cellular Respiration: Carbon Dioxide and Water
Cellular respiration is a metabolic pathway that occurs in the presence of oxygen. It produces ATP, which cells need to function. Glucose and oxygen are converted to carbon dioxide and water. In mitochondria, the electron transport chain creates a proton gradient that powers ATP synthesis. Carbon dioxide is then released from the cells and exhaled from the lungs.
Water is created when electrons pass along the electron transport chain and react with oxygen. This process is called oxidative phosphorylation and occurs on the inner mitochondrial membrane. ATP synthase also uses the proton gradient to attach phosphate groups to ADP and create ATP.
Anaerobic respiration does not make water since there is no oxygen. Some bacteria use molecules like sulfate or nitrate instead.
We can optimize our health by eating a healthy diet and exercising. Through these activities, we can ensure cells are functioning and ATP is produced through cellular respiration. Breathtaking, isn’t it?
The Role of Mitochondria in Cellular Respiration
Mitochondria play a crucial role in the process of cellular respiration, which involves the breakdown of glucose molecules to produce ATP
The role of mitochondria in cellular respiration cannot be understated as it is essential for the survival of the cell.
Mitochondria are unique in that they have their own DNA and are able to self-replicate. This is important for the efficient functioning of the cell as it ensures that there are enough mitochondria to carry out cellular respiration.
Additionally, mitochondria have a double membrane system that separates the mitochondrial matrix from the intermembrane space.
The enzymes responsible for the citric acid cycle are located in the mitochondrial matrix, while those involved in the electron transport chain are located in the inner mitochondrial membrane.
The Mitochondrial Membrane
The mitochondrial membrane is essential for cellular respiration. It has two layers, an outer and inner membrane. The inner membrane is important for ATP production. It has enzymes and electron transport chains on its surface.
The following table shows the importance of the Inner Membrane:
| Components | Functions |
| Cristae | Structural folds that increase surface area for enzymatic reactions |
| Electron Transport Chain | Performs oxidative phosphorylation to produce ATP |
| Enzymes | Catalyze specific reactions needed for ATP synthesis |
The intermembrane space also has unique environments for apoptosis and calcium signaling.
The Mitochondrial Matrix
The Intramitochondrial Compartment is an organelle powerhouse that provides energy to our cells. This innermost space is filled with a liquid-like substance called the Mitochondrial Matrix.
It houses many enzymes that break down glucose in the citric acid cycle (also known as the Krebs cycle) to produce ATP molecules.
The matrix also has a circular DNA molecule that encodes proteins essential for respiration and growth.
The Mitochondrial Matrix is unique for its ability to regulate calcium levels. Calcium ions are important for cellular signaling pathways and muscle contraction, so they must be carefully balanced.
Mitochondria take in calcium ions from the cytosol when there’s too much and redistribute them when needed.
Mutations in genes related to the Matrix can cause diseases. For example, Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD) is caused by mutations in the LCHAD gene, which encodes an enzyme within the mitochondrial matrix.
LCHAD has a range of symptoms, from vomiting and sleepiness to seizures.
It’s been established that 90% of ATP produced in mammal cells comes from mitochondria, which use oxidative phosphorylation in their cristae membranes.
Cellular respiration is a vital biochemical process. It breaks down glucose molecules inside cells to release energy. This process happens in three stages: glycolysis, the Krebs cycle, and oxidative phosphorylation.
Frequently Asked Questions
What is cellular respiration?
Cellular respiration is the process by which cells break down glucose and other molecules to produce energy in the form of ATP (adenosine triphosphate).
What are the stages of cellular respiration?
Cellular respiration has three main stages: glycolysis, the citric acid cycle (also known as the Krebs cycle), and oxidative phosphorylation (where ATP is produced).
What molecules are involved in cellular respiration?
Glucose is the main molecule involved in cellular respiration. Other molecules like pyruvate, NADH, FADH2, and ATP are also important in the process.
How does aerobic respiration differ from anaerobic respiration?
Aerobic respiration requires oxygen to produce ATP, while anaerobic respiration can produce ATP without the presence of oxygen. Aerobic respiration produces more ATP per glucose molecule, while anaerobic respiration produces less.
What is the electron transport chain?
The electron transport chain is a series of chemical reactions that occurs during oxidative phosphorylation. It involves transferring electrons from NADH and FADH2 to oxygen, resulting in the production of ATP.
What is fermentation?
Fermentation is a process involving a glycolytic pathway that occurs in the absence of oxygen. It converts pyruvate to other molecules to regenerate NAD+ for use in glycolysis. The end products of fermentation can include lactic acid, ethanol and carbon dioxide.
What is cellular respiration?
Cellular respiration is the process by which cells convert nutrients (mainly glucose) into ATP, which can be used as energy by the cell.
What are the different stages of cellular respiration?
Cellular respiration involves three main stages: glycolysis, the citric acid cycle, and oxidative phosphorylation (which includes the electron transport chain and chemiosmosis).
What is glycolysis?
Glycolysis is the first stage of cellular respiration, during which a molecule of glucose is broken down into two molecules of pyruvate, generating a small amount of ATP and NADH.
What is the citric acid cycle?
The citric acid cycle (also called the Krebs cycle) is a series of enzymatic reactions that occurs in the mitochondria of eukaryotic cells. During this cycle, acetyl-CoA (which is produced from pyruvate) is completely oxidized, yielding carbon dioxide, ATP, and NADH.
What is oxidative phosphorylation?
Oxidative phosphorylation is the final stage of cellular respiration, during which most of the ATP is generated. It includes the electron transport chain, which transfers electrons from NADH and FADH to molecular oxygen (creating a proton gradient across the inner membrane of the mitochondria), and chemiosmosis, which uses the energy from the proton gradient to produce ATP from ADP and inorganic phosphate.
What is aerobic respiration?
Aerobic respiration is the form of cellular respiration that uses oxygen as a reactant and produces the most ATP. It includes glycolysis, the citric acid cycle, and oxidative phosphorylation.
What is anaerobic respiration?
Anaerobic respiration is a form of cellular respiration that does not use oxygen as a reactant. It is less efficient than aerobic respiration and produces less ATP. This process is also called fermentation.
What are the end products of glycolysis?
The end products of glycolysis are two molecules of pyruvate, two molecules of ATP, and two molecules of NADH.
What are the end products of the electron transport chain?
The end products of the electron transport chain are a proton gradient across the inner membrane of the mitochondria and a large number of molecules of ATP (generated by chemiosmosis).
What is the role of NADH in cellular respiration?
NADH is a molecule that carries high-energy electrons that are used to produce ATP during cellular respiration. It is generated during glycolysis and the citric acid cycle, and is used as a reactant in the electron transport chain.
What is cellular respiration cycle?
Cellular respiration cycle is the process by which cells generate energy through the breakdown of glucose, using oxygen to produce ATP.
What are the important steps in cellular respiration cycle?
The important steps in cellular respiration cycle are glycolysis, pyruvate oxidation, citric acid cycle, electron transport chain and oxidative phosphorylation.
What is glycolysis?
Glycolysis is the first step of cellular respiration. It is the process by which a molecule of glucose is broken down into two molecules of pyruvate, resulting in the production of ATP and NADH.
What is pyruvate?
Pyruvate is a molecule that is produced during glycolysis from the breakdown of glucose. It acts as a starting point for the next step of cellular respiration, called pyruvate oxidation.
What is the citric acid cycle?
Citric acid cycle is also known as Krebs cycle. It is a series of chemical reactions that occurs in the mitochondria and is responsible for the complete breakdown of carbohydrate, lipids, and proteins into carbon dioxide, water, and energy.
What is the electron transport chain?
Electron transport chain is a process that takes place in the inner membrane of the mitochondria, where electrons from NADH and FADH2 are transported by a series of proteins, leading to the production of ATP.
What is oxidative phosphorylation?
Oxidative phosphorylation is a process where ATP is produced by the transfer of electrons from NADH and FADH2 to oxygen by the electron transport chain in the mitochondria.
What is aerobic respiration?
Aerobic respiration is a process that requires molecular oxygen and involves the complete breakdown of glucose to produce carbon dioxide, water, and energy in the form of ATP.
What is anaerobic respiration?
Anaerobic respiration is a process that occurs in the absence of molecular oxygen and involves the partial breakdown of glucose, resulting in the production of ATP and end products such as lactic acid or ethanol.
What are the end products of the electron transport chain?
The end products of the electron transport chain are ATP and water.
How is ATP used to produce energy in cellular respiration?
ATP is used as a source of energy in cellular respiration. ATP is produced during glycolysis, citric acid cycle, and oxidative phosphorylation, and is used to power various cellular processes, such as muscle contraction and protein synthesis.
Conclusion
Cellular respiration is a vital process that occurs in living organisms. It produces ATP, which is the primary energy source. Glucose gets broken down into CO2 and water, with energy being stored in ATP molecules. It happens in mitochondria and can be either aerobic or anaerobic.
