Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. After two-stage fermentation, degradation rates of glycinin and β-conglycinin contents reached 78.60% and 72.89%, respectively. Fermentation is a metabolic process that converts sugar (primarily glucose, fructose, and sucrose) to acids, gases or alcohol. The more commonly used of the two strategies -- aerobic respiration -- requires abundant oxygen. The material appearing on LIVESTRONG.COM is for educational use only. • Pyruvate oxidation occurs in the mitochondrion • Its purpose is to convert the pyruvate molecules to acetyl CoA which then goes into the citric acid cycle • Inputs are the two molecules of pyruvate • Outputs are 2 CO 2, 2 NADH 7. Lactic acid fermentation is the type of anaerobic respiration carried out by yogurt bacteria (Lactobacillus and others) and by your own muscle cells when you work them hard and fast. (ii) Lactic Acid Fermentation (Fig. If you're seeing this message, it means we're having trouble loading external resources on our website. Have questions or comments? The fermentation of pyruvic acid by yeast produces the ethanol found in alcoholic beverages. The former occurs when the byproduct pyruvate is converted to ethanol and carbon dioxide. Lactic Acid Fermentation. Alcoholic fermentation occurs by the action of yeast; lactic acid fermentation, by the action of bacteria. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. One glucose molecule gives two lactate molecules (Fig. The first step of alcoholic fermentation is the decarboxylation of pyruvic acid to acetaldehyde. Lactic acid breakdown of muscles results in muscle tissue rebuilding itself to become stronger. Lactic acid fermentation is the reason that muscles burn during an intense or long workout. any of the products or services that are advertised on the web site. Please update your bookmarks accordingly. Amasake: Also called sake, it is a rice drink that is fermented and … Lactic acid accumulates in your muscle cells as fermentation proceeds during times of strenuous exercise. Lactic acid can be produced by chemical synthesis or by fermentation. Where does it occur? Anaerobic Fermentation. 7.12). Homolactic fermentation (producing only lactic acid) is the simplest type of fermentation. Without these pathways, glycolysis would not occur and no ATP … Lactic acid is a substance made by muscle tissue and by red blood cells, which carry oxygen from your lungs to other parts of your body. This test measures the level of lactic acid, also known as lactate, in your blood. Records indicate that foods like kimchi may have been eaten even in the third and fourth centuries. The main hotspot is derived … In yeast, the anaerobic reactions make alcohol, while in your muscles, they make lactic acid. diagnosis or treatment. Lactic acid is formed by the reduction of pyruvate. Fermentation is the process of producing ATP in the absence of oxygen, through glycolysis alone. The more commonly used of the two strategies -- aerobic respiration -- requires abundant oxygen. An enzyme in the muscle cells then converts the pyruvic acid to lactic acid. If you are familiar with grouse, you know that these birds "flush" with great speed over short distances. NAD + is reused in glycolysis. If you run marathons, you probably have more red oxidative fibers, performing aerobic respiration. For more information contact us at info@libretexts.org or check out our status page at https://status.libretexts.org. Yeasts and many bacteria carry out alcohol fermentation, which takes place under anaerobic conditions, and produces ethanol) actic acid fermentation converts pyruvate to lactic acid, and regenerates NAD\(^+\) from \(NADH\). Lactic acid fermentation represents the easiest and the most suitable way for increasing the daily consumption of fresh-like vegetables and fruits. In fact, without oxygen, glucose is split into two pyruvate molecules through the metabolic process of glycolysis, which generates a small amount of energy. Lactic acid fermentation: In this pathway pyruvate is reduced to lactic acid. Literature data are accumulating, and this review aims at describing the main features of the lactic acid bacteria to be used for fermentation. Select When your muscle cells run out of oxygen they undergo lactic acid fermentation. The pyruvate from glycolysis undergoes a simple redo reaction forming lactic acid. This is a single step reaction carried out by Lactic acid bacteria (LAB) There are two types of lactic acid fermentation.i. Select pyruvate processing citric acid (Kreb's) cycle C. During fermentation, what is the oxidation of NADH coupled to? In this way we obtain a multivariable control problem with two inputs: and and two outputs: and . Alcoholic fermentation, or ethanol fermentation, is where pyruvate (from glucose metabolism) is broken down into carbon dioxide and ethanol by bacteria and yeast. Alcohol fermentation … The amount of salt added controls t he type and rate of the fermentation. Krebs cycle and electron transport system do not occur in fermentation. Unlike aerobic respiration, anaerobic respiration does not need oxygen. CK-12 Foundation by Sharon Bewick, Richard Parsons, Therese Forsythe, Shonna Robinson, and Jean Dupon. The lactic acid molecule is found naturally in plants, microorganisms, and animals, and may also be produced by the fermentation of carbohydrates or by chemical synthesis from coal, petroleum products, and natural gas. The bacteria convert the lactose sugar to glucose, which enters glycolysis and is followed by lactic acid fermentation. glucose → 2 lactic acid C 6 H 12 O 6 → 2 C 3 H 6 O 3. This produces just enough ATP to allow these short bursts of increased activity. There are two main types of anaerobic respiration, alcoholic fermentation and lactic acid fermentation. (In the presence of oxygen, human cells carry out aerobic respiration, which yields acetyl CoA. Learn about fermentation with free interactive flashcards. To achieve this, NADH donates its extra electrons to the pyruvate molecules, regenerating NAD\(^+\). On the other hand, in the latter type, pyruvate is converted to lactic acid. NAD+ also forms from NADH allowing glycolysis to continue making ATP . Definition. Lactic acid accumulates in the muscles and causes muscle cramps. There are two basic types of fermentation: alcoholic and lactic acid. Lactic acid is formed by the reduction of pyruvate. Recently, lactic acid fermentation has received much more attention because of the increasing demand for new biomaterials such as biodegradable and biocompatible polylactic products. Sugars are very important in fermentation and so is yeast. (3) the fermentation of the sugars to lactic acid; (4) the isolation of lactic acid from fermentation broth. used as a substitute for professional medical advice, Use of this web site constitutes acceptance of the LIVESTRONG.COM The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. glucose → 2 lactic acid C 6 H 12 O 6 → 2 C 3 H 6 O 3. 2 ATP are invested NADP is produced 4 ATP are produced for a net gain of 2 ATP Pyruvate is produced NADP gives up electrons and hydrogens to another molecule Lactic acid is produced: ... into what two parts are an amino acid broken? http://www.tempeh.info/fermentation/fermentation.php, http://www.tempeh.info/fermentation/...rmentation.php, information contact us at info@libretexts.org, status page at https://status.libretexts.org. Adopted a LibreTexts for your class? It should not be Recall that glycolysis breaks a glucose molecule into two pyruvate molecules, producing a net gain of two ATP and two NADH molecules. Lactic acid bacteria play a vital role in producing and preserving wholesome foods such as yogurt and pickles etc. The frozen samples of lactic acid bacteria were stored at −45 °C and the freeze-dried samples were stored either at −20 °C or at ambient temperature. What Are the Products of Lactic Acid Fermentation? Respiration is an essential physiological activity of all living organisms by which they obtain energy for all … As in the yeast, this reaction frees up the NAD while providing the cells with two ATP molecules from glycolysis. Lactic acid fermentation of fruits and vegetables has been around for centuries. The study was performed in two successive seasons (2011/2012 and 2012/2013), using about 150 tons of olives. list the steps of lactic acid fermentation in order from when glujcose enters the process: Definition. Lactic acid … Establish your “starter” cultures. The study identified environmental hotspots and compared an experimental seaweed production chain with conventional feedstocks. As such, the process is often called lactic acid fermentation, which has several products. Human cells have two strategies for burning glucose, or blood sugar, to liberate energy. If you are experiencing serious medical symptoms, please see the, National Library of Medicine’s list of signs you need emergency medical attention, PARTNER & LICENSEE OF THE LIVESTRONG FOUNDATION. Here’s a reminder what those are. It’s a little more complicated than that since some cultures utilize lactose in different ways. advertisements are served by third party advertising companies. ... What are the outputs of cellular respiration? During strenuous exercise, fermentation occurs in the muscles because of limited oxygen supply, creating lactic acid which also causes muscle cramps. Lactic acid fermentation produces lactic acid as the end product while the alcoholic fermentation produces alcohol and carbon dioxide as the end products. Fermentation has many uses in the food and fuel industry. A small amount of ATP produced (ENERGY) Lactic Acid Fermentation in animals & some bacteria. | Livestrong.com Beyond lactic acid fermentation and alcohol fermentation, many other fermentation methods occur in prokaryotes, all for the purpose of ensuring an adequate supply of NAD + for glycolysis (Table 2). In the absence of oxygen, human cells can carry out lactic acid fermentation, which yields lactate. Do you consider yourself a sprinter or a long distance runner? [ "article:topic", "authorname:soulta", "Lactic Acid Fermentation", "showtoc:no", "license:ccbync" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FCourses%2FUniversity_of_Kentucky%2FUK%253A_CHE_103_-_Chemistry_for_Allied_Health_(Soult)%2FChapters%2FChapter_15%253A_Metabolic_Cycles%2F15.3%253A_Lactic_Acid_Fermentation, Lactic Acid Fermentation: Muscle Cells and Yogurt. She's been teaching and writing about health, wellness and nutrition for more than 10 years. It basically occurs in yeast, bacteria and oxygen-starved muscle cells in order to ferment lactic acid. You may have notice this type of fermentation in your own muscles, because muscle fatigue and pain are associated with lactic acid. Lactic acid fermentation produces lactic acid and NAD +. Fermen, lactic acid fermenation. The simple equation for lactic acid fermentation is glucose ---glycolysis---> 2 pyruvate ---fermentation--> 2 lactic acid. Although humans are obligate aerobes (an organism which requires oxygen for cellular respiration), our muscle cells have not given up on ancient pathways which allow them to keep producing ATP quickly when oxygen runs low. Alcoholic fermentation. (1) Alcoholic fermentation : the type of fermentation in which ethyl alcohol is the main end product . Learn vocabulary, terms, and more with flashcards, games, and other study tools. Lactic acid is widely used in the food industry as an acidulant, preservative, precursor for stearoyl-2-lactylates. They tolerate salt concentrations up to 8 percent (and higher in some cases), can grow over a similarly wide pH range (4.5-8.2, though they fare better than Leuconostoc as pH decreases), and survive temperatures from 60°F to 95°F. Lactic acid fermentation happens in our muscle cells when we are exercising feverishly, while alcoholic fermentation is used in yeast cells and is what leads to beer, bread, and wine. Are Drumsticks and Athletic Prowess Related? Legal. 6.12 a. Pyruvic Acid converted to ethanol and CO 2. 2. What is the biological difference between light meat and dark meat? It occurs in two major steps: glycolysis and fermentation. Anaerobic fermentation is a complicated process that is 100% natural and is carried out on microorganisms. Fermentation Lactic acid fermentation is the process by which our muscle cells deal with pyruvate during anaerobic respiration. , The equation of lactic acid fermentation can be written as: C 6 H 12 O 6 → C 3 H 6 O 3 + energy. This type of fermentation is used routinely in mammalian red blood cells and in skeletal muscle that has an insufficient oxygen supply to allow aerobic respiration to continue (that is, in muscles used to the point of fatigue). The two main types of fermentation are: 1.) When our cells need energy, they break down simple molecules like glucose. Read this BiologyWise article to know what anaerobic fermentation is and some interesting facts about this process. actic acid fermentation converts pyruvate to lactic acid, and regenerates NAD + from N A D H. 130, fig. The bacteria ferment sugars in the food to form lactic acid, which then prevents the growth of food poisoning bacteria and moulds. They shift to lactic acid fermentation. Lactic acid fermentation converts the 3-carbon pyruvate to the 3-carbon lactic acid \(\left( \ce{C_3H_6O_3} \right)\) (see figure below) and regenerates NAD\(^+\) in the process, allowing glycolysis to continue to make ATP in low-oxygen conditions. The benefits extend to humans who enjoy these foods, as well (Figure \(\PageIndex{5}\)). The loss of carbon dioxide reduces the size of the molecule by one carbon, making acetaldehyde. Moreover, we do not select every advertiser or advertisement that appears on the web site-many of the Products of Fermentation. When human cells ferment glucose, one of the products is lactic acid. Eventually, however, the lactic acid buildup causes intense fatigue, and the muscle stops contracting. Instead, glycolysis requires the involvement of a substance called NAD+. To allow the continuous production of some ATP, your muscle cells use lactic acid fermentation. Bacteria perform fermentation, converting carbohydrates into lactic acid. In addition to malic acid, tartaric acid, and citric acid, 10–16 mg/L pyrogenic acid is accumulated by fermentation, α-ketoglutaric acid, 90–119 mg/L, acetic acid, lactic acid, etc. The fermentation method used by animals and some bacteria like those in yogurt is lactic acid fermentation (Figure 1). Normally, the level of lactic acid in the blood is low. (15.3.1) C 3 H 3 O 3 (pyruvate) + NADH → C 3 H 6 O 3 (lactic acid) + NAD +. Products of Fermentation. Perhaps its greatest industrial potential is for biodegradable polymers such as polylactic acid. Start studying Biology. Short spurts of sprinting are sustained by fermentation in muscle cells. No human muscle is all red or all white, but chances are, if you excel at sprinting short distances or at a sport such as weight lifting, you have more white glycolytic fibers in your leg muscles, allowing anaerobic respiration. This occurs routinely in mammalian red blood cells and in skeletal muscle that has insufficient oxygen supply to allow aerobic respiration to continue (that is, in muscles used to the point of fatigue). And lactic acid fermentation isn't so much about producing more ATPs, it's more about recycling the pyruvate and the NADH. Hetero lactic fermentation; Homolactic fermentation: In homolactic fermentation, end product is lactic acid. What is the function? In essence, by converting lactic acid to pyruvate, the body maintains a valuable source of carbon and avoids wasting potentially energy-yielding molecules. These products are used commercially in foods, vitamins, pharmaceuticals, or as industrial chemicals. The definition of lactic acid is “an organic acid (C 3 H 6 O 3) present especially in muscle tissue as a by-product of anaerobic glycolysis, produced in carbohydrate matter usually by bacterial fermentation, and used especially in food and medicine and in industry.” 7.12): Pyruvic acid receives hydrogen from NADH 2, producing lactic acid and oxidized NAD +. Homolactic fermentation is the simple type of fermentation. Privacy Policy After grading and sorting of the olives, pickling process follows, first lye treatment w/ ._% - _._%lye to barely penetrate the skin; Aeration treatment w/ stirring or administration of compressed air to darken the skin. Complete the table to compare and contrast the two stages of fermentation: Location Inputs Outputs (including waste products) Amount of ATP produced Glycolysis Cytoplasm Glucose Pyruvate, ATP, and e-Two Fermentation Reactions Cytoplasm Pyruvate and NADH NAD+ and Lactic Acid Zero Write a one-sentence description of each stage of fermentation, summarizing the information you have provided … Industrially, lactic acid can be produced by chemical synthesis or by fermentation. What are the inputs and outputs of pyruvate oxidation? The LIVESTRONG Foundation and LIVESTRONG.COM do not endorse Usually this is pyruvate formed from sugar through glycolysis.The reaction produces NAD + and an organic product, typical examples being ethanol, lactic acid, and hydrogen gas (H 2), and often also carbon dioxide.However, more exotic compounds can be produced by fermentation, such as butyric acid and acetone. Describes the process of lactic acid fermentation. This is accomplished by the metabolic processes of the bacterial starter culture the cheesemaker uses. Copyright © LIVESTRONG is a registered trademark of the LIVESTRONG Foundation. The LibreTexts libraries are Powered by MindTouch® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. . Terms of Use In alcoholic fermentation , pyruvate changes to alcohol and carbondioxide . The two main types of fermentation are alcoholic and lactic. ; Humans, animals and some bacteria engage in lactic acid fermentation as an anaerobic metabolic strategy, in contrast to yeast and other bacteria that use ethanolic fermentation instead. Since there is a limited supply of NAD\(^+\) available in any given cell, this electron acceptor must be regenerated to allow ATP production to continue. What output of lactic acid fermentation is an input in the glycolysis oxidative phosphorylation respiration? Alcoholic fermentation 2.) This work studies the inoculation conditions for allowing the survival/predominance of a potential probiotic strain (Lactobacillus pentosus TOMC-LAB2) when used as a starter culture in large-scale fermentations of green Spanish-style olives. The process of fermentation doesn't actually yield energy. We have moved all content for this concept to for better organization. Fermentation of lactic acid has wide applications in the food and beverage industries. The difference is more pronounced in chickens and grouse (see figure below), which stand around all day on their legs. Lactic acid fermentation is the conversion of pyruvate to lactate, and occurs only under anaerobic conditions. Learn vocabulary, terms, and more with flashcards, games, and other study tools. One product of lactic acid fermentation is lactic acid itself. The liver can recycle lactic acid by converting it back into pyruvate, which can be burnt under oxygen-rich conditions for further energy, note Drs. Lactic Acid Formation. Mixed Acid Fermentation: This type of fermentation occurs characteristically in bacteria belonging … However, the key difference between lactic acid and alcoholic fermentation is that the lactic acid fermentation results in lactate from glucose. Copyright Policy Overall, one molecule of glucose (or any six-carbon sugar) is converted to two molecules of lactic acid: . These food products are important in the digestion process. This occurs in the muscles in animals when they need energy faster than the blood can supply oxygen and is also occurs in some kinds of bacteria such as lactobacilli. For long periods of time, they carry out aerobic respiration in their "specialized-for-endurance" red muscles. Describe how bacteria, including those we employ to make yogurt, make ATP in the absence of oxygen. The second reaction is catalyzed by alcohol dehydrogenase to oxidize NADH to NAD + and reduce acetaldehyde to ethanol. The muscle cells convert glucose to pyruvic acid. If 2-5% salt is used, the fermentation is carried out by a series of bacteria that produce lactic acid. Fermentation is a metabolic process in which an organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid. For Lactobacillus bacteria, the acid resulting from fermentation kills bacterial competitors in buttermilk, yogurt, and some cottage cheese. Although racemic lactic acid is always produced by chemical synthesis from petrochemical resources, an optically pure L(+)- or D(-)-lactic aci… Once produced, it's essentially metabolic waste. Discuss how your muscles continue to work for you even when your respiratory and cardiovascular system can no longer keep up a continuous supply of oxygen. Production of this acid is commonly carried out by the lactic acid bacteria, Lactobacillus spps. Less commonly used, because it yields approximately 15 times less energy per glucose molecule, is an anaerobic strategy, called fermentation, which does not depend upon oxygen. Lactic acid fermentation in muscles results in the accumulation of lactic acid in the tissues, which leads to sore muscles. Lactic acid fermentation usually takes place while the olives are being held in brine. Figure 2 shows the two main processes of lactic acid production. Both processes produce energy, but a low amount of energy. The frozen chambers considered (−45 °C and −20 °C) were laboratory freezers (340 L and 192 L, respectively) or walk-in freezers (50 m 3 with a surface area of 20 m 2 ). Pyruvate from glycolysis undergoes a simple redox reaction, forming lactic acid. Fermentation is mainly of three types, and commonly, it is classified under 2 categories; alcoholic and lactic acid. Allison Soult, Ph.D. (Department of Chemistry, University of Kentucky). Input and output of lactic acid fermentation = Input is NADH; pyruvate and output is NAD + Explanation: There are two different types of fermentation Alcoholic fermentation and lactic acid fermentation. Glossary of Fermentation Terms. The pH of fermented SBM (FSBM) decreased to 4.78 ± 0.04 and lactic acid content reached 183.38 ± 4.86 mmol/kg. Such "sprinting" flight depends on anaerobic respiration in the white cells of breast and wing muscle, allowing rapid production of ATP in low oxygen situations. Lactic acid fermentation. Quizlet, San Francisco, California. 6. Would you believe it has something to do with muscle color? For best results enter two or more search terms. In homolactic fermentation, one molecule of glucose is ultimately converted to two molecules of lactic acid. Glycolysis always occurs under anaerobic conditions, and glucose needs to be broken down to fuel the sprinter. Lactic Acid Fermentation. Human cells have two strategies for burning glucose, or blood sugar, to liberate energy. Still, lactic acid does represent a valuable source of reduced carbon, which has the potential to yield energy. The most pertinent species to lactic acid fermentation is P. cerevisiae. This type of anaerobic respiration is called lactic acid fermentation that produces just 2 ATPs per glucose molecules. As such, one glucose, with six carbon atoms, splits neatly into two molecules of lactic acid, meaning that unlike ethanolic fermenters, lactic acid fermenters don't produce carbon dioxide as a byproduct. the two main types of fermentation are alcoholic fermentation and lactic acid fermentation. Lactic a … Both types of microorganisms are present on grapes and on cellar equipment. Lactic acid fermentation of raw veggies results in savory pickles that make … Or between the two types of runners? It helps in the production of ethanol in alcoholic drinks and carbon dioxide. In alcoholic fermentation pyruvic acid is converted into ethy lalcohol. Lactic Acid Fermentation. While there are a number of products from fermentation, the most common are ethanol, lactic acid, carbon dioxide, and hydrogen gas (H 2). The two most common types of fermentation are (1) alcoholic fermentation and (2) lactic acid fermentation. Lactic Acid Fermentation: Definition, Products & Equation In this lesson, we'll be looking at the process of lactic acid fermentation. Mary Campbell and Shawn Farrell in their book, "Biochemistry." While there are a number of products from fermentation, the most common are ethanol, lactic acid, carbon dioxide, and hydrogen gas (H 2). \[\ce{C_3H_3O_3} \: \text{(pyruvate)} \: + \ce{NADH} \rightarrow \ce{C_3H_6O_3} \: \text{(lactic acid)} \: + \ce{NAD^+}\]. Yeasts are better adapted to growth in grape must than … The enzyme lactic dehydrogenase catalyzes the reaction. This type of fermentation occurs in yeasts and in certain bacteria. For example, yeast performs fermentation to obtain energy by converting sugar into alcohol. This is very common in yeast (unicellular fungus) and also seen in some bacteria. For chicken or turkey dinners, do you prefer light meat or dark? , for production of cheese, yogurt, sauerkraut, bread, and kefir, and for imparting a peculiar sour taste to such food items. Hoefnagels Text Pg. Alcoholic Fermentation in plants and yeast. The fermentation method used by animals and certain bacteria, like those in yogurt, is lactic acid fermentation (Figure 2). and Well what we're gonna talk about in this video is one potential pathway, and that's lactic acid fermentation, which is one of the two major forms of fermentation. It is probably the only respiration process that does not produce a gas as a byproduct. You may have not been aware that your muscle cells can ferment. For many cheeses, lactose ends up as lactic acid. Lactic Acid Fermentation. Lactic acid fermentation and alcoholic fermentation are two types of fermentation processes that occur under anaerobic conditions. Both glycolysis and lactic acid fermentation occur in the cytosol. #2. The bacteria carry out lactic acid fermentation in the absence of oxygen. NAD+ is an important product of lactic acid fermentation because it allows the energy-yielding process of glycolysis to continue. They primarily produce lactic acid. To achieve this, NADH donates its extra electrons to the pyruvate molecules, regenerating NAD +. Alcoholic fermentation Hard-working muscles often metabolize glucose by lactic acid fermentation. Alcoholic Fermentation Location : Cytoplasm : Lactic Acid Fermentation Location : Muscles of Animal Cells : Type of Cell - Photosynthesis : Plant : Type of Cell - Lactic Acid Fermentation : Eukaryotes : Type of Cell - Alcoholic Fermentation : Yeast, Bacteria : Type of Cell - Glycolysis : Eukaryotes : Type of Cell - Kreb's Cycle : Eukaryotes She has a Bachelor of Science in zoology, a Bachelor of Science in psychology, a Master of Science in chemistry and a doctoral degree in bioorganic chemistry. Many other … Lactic acid can be produced by two fermentation homofermentation and heterofermentation. acid, one molecule of ethanol and one molecule of carbon dioxide. Reginald Garrett and Charles Grisham in their book, "Biochemistry," lactic acid differs from ethanol by one carbon atom; lactic acid has three carbons, while ethanol has two. Garrett and Grisham. Lactic acid itself isn't a particularly useful product -- instead, it's produced as a byproduct in the process of making NAD+. Microbes are naturally present in the air you breathe, but to begin … Glycolysis is the first step … Start studying biology chapter 10. This anaerobic process produces lactic acid as a byproduct: Lactic acid fermentation: This anaerobic process produces alcohol/ethanol as a byproduct: Muscle color reflects its specialization for aerobic or anaerobic metabolism. Click here to let us know! finding showed that there are two types of fermentation: alcoholic and lactic acid. Leaf Group Ltd. Each circle represents a carbon atom. In alcoholic fermentation molecules are converted into ethanol with the production of carbon dioxide, whereas in lactic fermentation, molecules are converted into lactic acid, and there is no production of carbon dioxide. This simulation, along with “Fermentation: Optimize bio-ethanol production,” was adapted from learning objectives in the original “Fermentation” simulation.