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Atomic particles with a negative charge (-) found outside the nucleus of an atom. Bond that forms when electrons are shared equally. Bond that forms when electrons between atoms are shared. Study with Quizlet and memorize flashcards containing terms like Carbohydrate Examples, Disaccharide, Monosaccharide and more.
Metabolic pathways that release energy by breaking down complex molecules into simpler compounds. Three-carbon compound that forms as an end product of glycolysis. Study with Quizlet and memorize flashcards containing terms like metabolism, metabolic pathway, anabolic pathway and more.
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- Cellular Respiration Definition
- Cellular Respiration Overview
- Cellular Respiration Equation
- Cellular Respiration Steps
- Products of Cellular Respiration
- Purpose of Cellular Respiration
- Types of Cellular Respiration
Cellular respiration is the process through which cells convert sugars into energy. To create ATP and other forms of energy to power cellular reactions, cells require fuel and an electron acceptor which drives the chemical process of turning energy into a useable form.
Eukaryotes, including all multicellular organisms and some single-celled organisms, use aerobic respiration to produce energy. Aerobic respiration uses oxygen – the most powerful electron acceptor available in nature. Aerobic respirationis an extremely efficient process allows eukaryotes to have complicated life functions and active lifestyles. How...
Aerobic Respiration Equation
The equation for aerobic respiration shows glucose being combined with oxygen and ADP to produce carbon dioxide, water, and ATP: C6H12O6 (glucose)+ 6O2 + 36 ADP (depleted ATP) + 36 Pi (phosphate groups)→ 6CO2 + 6H2O + 36 ATP You can see that once it is completely broken down,the carbon molecules of glucose are exhaled as six molecules of carbon dioxide.
Lactic Acid Fermentation Equation
In lactic acid fermentation, one molecule of glucose is broken down into two molecules of lactic acid.The chemical energy that was stored in the broken glucose bonds is moved into bonds between ADP and a phosphate group. C6H12O6 (glucose) + 2 ADP (depleted ATP) + 2 Pi (phosphate groups) → 2 CH3CHOHCOOH (lactic acid) + 2 ATP
Alcoholic Fermentation Equation
Alcohol fermentation is similar to lactic acid fermentation in that oxygen is not the final electron acceptor. Here, instead of oxygen, the cell uses a converted form of pyruvate to accept the final electrons.This creates ethyl alcohol, which is what is found in alcoholic beverages. Brewers and distillers use yeast cells to create this alcohol, which are very good at this form of fermentation. C6H12O6 (glucose) + 2 ADP (depleted ATP) + 2 Pi (phosphate groups)→ 2 C2H5OH (ethyl alcohol) + 2 CO2...
Step 1
Glycolysis is the only step which is shared by all types of respiration. In glycolysis, a sugar molecule such as glucose is split in half, generating two molecules of ATP. The equation for glycolysis is: C6H12O6 (glucose) + 2 NAD+ + 2 ADP + 2 Pi → 2 CH3COCOO− + 2 NADH + 2 ATP + 2 H2O + 2H+ The name “glycolysis” comes from the Greek “glyco,” for “sugar” and “lysis” for “to split.” This may help you to remember that glycolysis it the process of splitting a sugar. In most pathways, glycolysis st...
Step 2
Reduction is the next part of the process. In chemical terms, to “reduce” a molecule means to add electrons to it. In the case of lactic acid fermentation, NADH donates an electron to pyruvic acid, resulting in the end products of lactic acid and NAD+. This is helpful to the cell because NAD+ is necessary for glycolysis. In the case of alcoholic fermentation, pyruvic acid undergoes an additional step in which it loses an atom of carbon in the form of CO2. The resulting intermediate molecule,...
Step 3
Aerobic respiration takes these processes to another level. Instead of directly reducing intermediates of the Krebs cycle, aerobic respiration uses oxygen as the final electron receptor. But first, the electrons and protons bound to electron carriers (such as NADH), are processed through the electron transport chain.This chain of proteins within the mitochondrial membrane uses the energy from these electrons to pump protons to one side of the membrane. This creates an electromotive force, whi...
ATP
The main product of any cellular respiration is the molecule adenosine triphosphate (ATP). This molecule stores the energy released during respiration and allows the cell to transfer this energy to various parts of the cell. ATP is used by a number of cellular components as a source of energy. For example, an enzyme may need energy from ATP to combine two molecules. ATP is also commonly used on transporters, which are proteins that function to move molecules across the cell membrane.
Carbon Dioxide
Carbon dioxide is a universal product created by cellular respiration. Typically, carbon dioxide is considered a waste product and must be removed. In an aqueous solution, carbon dioxide creates acidic ions.This can drastically lower the pH of the cell, and eventually will cause normal cellular functions to cease. To avoid this, cells must actively expel carbon dioxide.
Other Products
While ATP and carbon dioxide are regularly produced by all forms of cellular respiration, different types of respiration rely on different molecules to be the final acceptors of the electrons used in the process.
All cells need to be able to obtain and transport energy to power their life functions. For cells to continue living, they must be able to operate essential machinery, such as pumps in their cell membranes which maintain the cell’s internal environment in a way that’s suitable for life. The most common “energy currency” of cells is ATP – a molecule...
Aerobic Respiration
Eukaryotic organisms perform cellular respiration in their mitochondria – organelles that are designed to break down sugars and produce ATP very efficiently. Mitochondria are often called “the powerhouse of the cell” because they are able to produce so much ATP! Aerobic respiration is so efficient because oxygen is the most powerful electron acceptor found in nature.Oxygen “loves” electrons – and its love of electrons “pulls” them through the electron transport chain of the mitochondria. The...
Fermentation
Fermentation is the name given to many different types of anaerobic respiration, which are performed by different species of bacteria and archaebacteria, and by some eukaryotic cells in the absence of oxygen. These processes can use a variety of electron acceptors and produce a variety of byproducts. A few types of fermentation are: 1. Alcoholic fermentation– This type of fermentation, performed by yeast cells and some other cells, metabolizes sugar and produces alcohol and carbon dioxide as...
Methanogenesis
Methanogenesis is a unique type of anaerobic respiration that can only be performed by archaebacteria. In methanogenesis, a fuel source carbohydrate is broken down to produce carbon dioxide and methane. Methanogenesis is performed by some symbiotic bacteria in the digestive tracts of humans, cows, and some other animals.Some of these bacteria are able to digest cellulose, a sugar found in plants that cannot be broken down through cellular respiration. Symbiotic bacteria allow cows and other a...
Biology is a science, but what exactly is science? What does the study of biology share with other scientific disciplines? Science (from the Latin scientia, meaning “knowledge”) can be defined as knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method. It becomes ...
scientific law a description, often in the form of a mathematical formula, for the behavior of some aspect of nature under certain specific conditions scientific method
AP Biology glossary of key terms with definitions, must-know facts, and related terms you need to know for your exam.
