How do cells get most of their energy?

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There are two processes by which cells secure the energy they need to conduct life processes.  Plant cells undergo a process known as photosynthesis, which takes carbon dioxide from the atmosphere, water from the ground, uses energy, usually sunlight from the sun to produce glucose, which is used for the plant cells life processes.  Oxygen is given off as a waste product in this process.  Another process, used primarily by animal cells, is cellular respiration.  In this process, the glucose mentioned as a product of photosynthesis, is taken by the animal cell and broken down by oxidizing it with oxygen.  This releases energy, which is stored for use by the animal cell in the form of ATP.  Carbon dioxide and water are two waste products produced by this process.  Both these processes are described as "win-win" processes, because each one produces what the other one needs, in terms of reactants.

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Cells obtain energy by the process of cellular respiration. When this occurs, the chemical energy stored in the bonds of food, usually glucose is converted into adenosine triphosphate(ATP). This is a high-energy compound used by cells as a fuel to carry out life processes. There are waste products that result from respiration. Respiration is a catabolic reaction--this means that larger molecules are broken into smaller ones, accompanied by the release of energy. Respiration occurs in small steps in the cell, using special enzymes to catalyze the reaction. In aerobic respiration, oxygen plus glucose combines and 36 ATP are produced for cellular energy. The wastes that form are carbon dioxide and water. In anaerobic bacteria, and yeasts, respiration can occur without the presence of oxygen, by the process called fermentation. In this case, the end product is 2 ATP to be used for cell energy. In yeasts, they also produce the wastes ethanol as well as carbon dioxide gas. In anaerobic bacteria, they  produce the waste lactic acid. The answer to your question is that cells use ATP for energy.

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How do cells obtain energy?  

Cells require energy to perform work. Energy is obtained from extracellular sources. The process of photosynthesis by producers such as algae and green plants can convert light energy into chemical energy in the form of organic compounds such as glucose. Glucose is essentially stored or potential energy that can be utilized by living cells during cellular respiration.

The process of respiration results in ATP which can be regenerated from ADP. The ATP molecules are then used by cells to perform work like growth, synthesis and other metabolic activities. During aerobic respiration, three stages occur including glycolysis, the citric acid cycle and oxidative phosphorylation. The cell can generate 32-34 molecules of ATP. If an organism carries out anaerobic respiration or fermentation, they carry out glycolysis and generate only 2 ATP molecules.

Organic molecules contain potential energy that is released via a catabolic pathway. Enzymes are necessary to facilitate these reactions and eventually, the energy stored in organic compounds is released as these compounds are broken down into simpler waste products containing less energy. In essence, during aerobic respiration, glucose is used as a fuel and in the presence of oxygen, it is broken down to form carbon dioxide, water, plus energy in the form of heat and ATP. The change in free energy is -686 kcal/mole of glucose and it is an exergonic reaction. The 32-34 ATP that are formed can be used for cellular work. 

In anaerobic respiration, glucose is only partially degraded and only some of its potential energy is converted to 2 ATP in the absence of oxygen. In alcohol fermentation which is carried out by yeast, glucose is converted to ethanol and carbon dioxide plus 2 ATP. In lactic acid fermentation, carried out by some fungi and bacteria, glucose is converted to lactic acid plus 2 ATP.

To summarize, in order for living things to obtain energy to stay alive, organic molecules must come from an outside source. Through the process of cellular respiration, cells will be able to regenerate ATP to be used as the energy currency for life processes.

 

 

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How do cells obtain energy?  

Cells obtain energy through the process of cellular respiration. This process can take place both aerobically as well as anaerobically. In aerobic respiration, the food (in the form of glucose molecules) reacts with oxygen and produces carbon dioxide and water molecules, along with ATP (or adenosine triphosphate) molecules. The balanced chemical equation for this reaction can be written as:

`C_6H_12O_6 + 6O_2 -> 6CO_2 + 6H_2O + ATP`

These ATP molecules are the energy currency. Energy is released (on the order of 30.6 kJ/mol) when one of the phosphate bonds is broken and ATP converts to ADP molecule. 

One can think of ATP molecules as rechargeable batteries. When cells need energy they can convert stored ATP to ADP. And when food is oxidized, ADP converts back to ATP.

Anaerobic breakdown of food is much less efficient as compared to aerobic respiration and generates very few ATP molecules.

Hope this helps. 

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How do cells obtain energy?  

The process that produces energy for the body to use is called cellular respiration.

ATP the energy source used by cells. ATP stands for adenosine triphosphate. ATP is produced during cellular respiration.  

Cellular respiration can occur in the presence or absence of oxygen. However, much more energy is produced for the body when cellular respiration is completed in the presence of oxygen. In the presence of oxygen, 34-38 ATP are produced. In the absence of oxygen, the net yield of ATP produced is 2.

ATP is formed in the presence of oxygen during the process that is known as aerobic cellular respiration. This process occurs within mitochondria of eukaryotic cells. There are three main parts of aerobic cellular respiration- glycolysis, Krebs Cycle, and the electron transport chain. Overall, aerobic cellular respiration converts the sugar called glucose and oxygen gas into carbon dioxide gas, water, and 34-36 ATP.

Here, the processes that occur during each phase of aerobic cellular respiration can be read in greater detail.

Anaerobic respiration is sometimes referred to as fermentation. Fermentation is a metabolic process in which organisms convert carbohydrates, such as starch or sugar, into lactic acid or alcohol.

Ethanol fermentation is the type of fermentation that produces alcohol. It is done by yeast and some strains of bacteria. During ethanol fermentation, pyruvate from glucose metabolism is broken into ethanol and carbon dioxide.  Because ethanol fermentation produces alcohol, it is used to produce beer and wine. The carbon dioxide produced by ethanol fermentation is advantageous in the making of breads.

During lactic acid fermentation, six-carbon carbohydrates, such as the pyruvate molecules from glycolysis or lactose, are converted into cellular energy (ATP) and lactic acid. Lactic acid occurs within muscle cells during intense intervals of activity when energy is needed at a faster rate than oxygen can be supplied. The lactic acid produced is the “burn” that athletes feel after an intense workout.

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How does a cell obtain energy?

Adenosine Triphosphate (ATP)

ATP molecules are used for energy by cells. You can think of ATP as a molecule that stores energy in its bonds. When ATP bonds are broken, energy is released for cells to use. Cells are able to create ATP molecules for energy through the metabolism of glucose.

Origins of Glucose

  • Plant Cells: Plant cells can produce glucose molecules through the process of photosynthesis. During photosynthesis, plant cells are able to convert light energy from the sun into glucose molecules. The process of photosynthesis occurs in a plant cell organelle called the chloroplast.
  • Animal Cells: Animal cells acquire glucose through the consumption of food by the organism. 

Metabolism of Glucose into Energy Stored in ATP Molecules

  1. Glycolysis: Glycolysis begins the process of glucose metabolism. The process of glycolysis occurs in the cytoplasm, fluid which fills the innercellular space. During this process, each glucose molecule is converted into two molecules of pyruvate. 
  2. Cellular Respiration: Cellular respiration occurs in the mitochondria. During this process, oxygen from the environment is used to convert a pyruvate molecule into three molecules of carbon dioxide. The energy that is created during this process is stored in ATP molecules. There are three sub-pathways that occur during cellular respiration: pyruvate oxidation, the citric acid (Krebs) cycle, and the electron transport chain.
  3. Fermentation: Fermentation occurs in the cytoplasm of the cell in the absence of oxygen. During this process, a pyruvate molecule is converted to lactic acid or ethanol. These reacctions result in the production of ATP molecules. The process of fermentation is much less efficient at producing ATP molecules than the process of cellular respiration. 
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How do the cells in your body get energy?

All parts of our bodies require energy- our brains, stomach, muscles, etc. Even when we are sleeping, our bodies require energy! Cells in your body get energy from the foods that are eaten, such as glucose (a sugar). This food is ingested via consumption and digested via the digestive system. Food is initially mechanically digested in the mouth. The stomach, intestines and other parts of the digestive system then chemically digest the food. Eventually, through diffusion, the glucose and other nutrients are delivered to the mitochondria of your cells. Here, the glucose is converted into energy via the process known as cellular respiration. Cellular respiration converts glucose and oxygen into water, carbon dioxide and usable form of energy called ATP (this stands for adenosine triphosphate). 

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What process do most cells use to obtain energy?

Cellular respiration is the process by which most of the cells generate energy from complex chemical molecules. In simplest terms, the complex chemical molecules (such as glucose, etc.) are broken down in a series of reaction. At each step, these molecules (also known as donors) donate electrons, which are accepted by an electron acceptor (which is oxygen, in the case of respiration). In the end, after complete oxidation of the chemical molecule, carbon dioxide and water are generated along with energy in the form of adenosine triphosphate (ATP) molecules. The ATP molecules can be converted to energy, as and when required by the cells. The aerobic process of cellular respiration converts as much as half of the energy stored in the chemical substrate (food) into energy usable by the organism. In the absence of oxygen, a process known as fermentation or anaerobic respiration is used by the cells to generate energy.

Hope this helps. 

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