...1. A. Types of beer Yeasts that ferment at warmer temperatures, usually between 15.5 and 24 °C (60 and 75 °F), form a layer of foam on the surface of the fermenting beer, which is why they are referred to as top-fermenting yeasts. Yeasts that ferment at considerably lower temperatures, around 10 °C (50 °F), have the ability to process a chemical compound known as raffinose, a complex sugar created during fermentation. These yeasts collect at the bottom of the fermenting beer and are therefore referred to as bottom-fermenting yeast. The majority of beer in production today is fermented in this way and is called lager. Beer style Beer style is a term used to differentiate and categorize beers by factors such as color, flavor, strength, ingredients, production method, recipe, history, or origin. The modern concept of beer style is largely based on the work of writer Michael Jackson in his 1977 book The World Guide To Beer in which he categorized beers from around the world into style groups according to local customs and names.[1] In 1989, Fred Eckhardt furthered Jackson's work publishing The Essentials of Beer Style.[2] Although the systematic study of beer styles is a modern phenomenon, the practice of distinguishing between different varieties of beer is ancient, dating to at least 2000 BC. The study of what constitutes a beer's style may involve provenance,[3] local tradition,[4] ingredients,[5] and/or empirical impression, which is conventionally broken down into...
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...Yeast Fermentation Copyright © 2000 Sarah Phillips Sarah Phillips, Inc. All rights reserved. Yeast is the most commonly used leavener in bread baking and the secret to great bread making lies in its fermentation, or the metabolic action of yeast. It is the magical process that allows a dense mass of dough to become a well-risen and flavorful loaf of bread. In order for fermentation to take place, all yeast needs food, moisture and a controlled warm environment. Its byproducts from consuming food are the gas carbon dioxide, alcohol, and other organic compounds. The gas is the rising agent in bread, and the other "waste" products create the subtle flavors and texture that make a good loaf. HOW DOES IT WORK? In bread baking, we are trying to ferment grain in order to leaven it. We are also trying to release sugars trapped in the complex starch molecules to be used as yeast food, and much of it for flavor and crust color (caramelization). Yeast is a single-celled organism and only certain strains are used for fermenting grain. Yeast activation and the initiation of fermentation are triggered by hydration, from either water or some other liquid, and the presence of a food source. Fermentation ends at 140 degree F during baking when heat kills the yeast. (Fermentation can end earlier, if the yeast is killed by other factors.) Yeast feeds on sugar derived from the complex starch molecules from flour, a complex carbohydrate. The starch molecules are broken apart into simpler...
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...4-3-16 BIO 111 A Fermentation with Yeast Abstract Fermentation is a process where the sole energy extraction pathway for oxidizing fuel molecules without oxygen (KhanAcademy). Fermentation is very essential for various living organisms, for example, bacteria, and yeast because it helps them receive energy that is required for life process. Various sugars can impact the fermentation rate. In this lab, the impact of glucose, lactose, and fructose on fermentation in yeast was investigated. Fructose had the faster speed of fermentation than lactose, but slower than glucose. Introduction Fermentation is the pathway following glycolysis, a metabolic process in cellular respiration in which cells create ATP. Glycolysis and fermentation are anaerobic processes, which means that they do not require the presence of oxygen to happen. There are two types of fermentation alcoholic and lactic acid. Both this types of fermentation require such reactants as NADH and pyruvic acid. Fermentation is important to numerous living organisms, such as bacteria, and yeast to obtain energy. Alcoholic fermentation is significant for human beings; it has been used to produce alcoholic beverages and many other items. Lactic acid is waste of bacteria and is used to produce cheeses, yogurt, sour cream, etc (Levine, Miller, 2010). Sugars, as source of food, impact the speed of fermentation. In this lad, glucose, lactose, and fructose are being investigated, with glucose in 30 C water as a control...
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...56 Define the following terms: Cellular respiration (aerobic respiration) (2 points) Cellular respiration is the process by which cells get their energy in the form of ATP. There are two types of cellular respiration, aerobic and anaerobic. Aerobic respiration is more efficient and can be used in the presence of oxygen. Aerobic respiration, or cell respiration using oxygen, uses the end product of glycolysis in the TCA cycle to produce more energy currency in the form of ATP than can be obtained from an anaerobic pathway. Fermentation (anaerobic respiration) (2 points) Fermentation is a metabolic process converting sugar to acids, gases or alcohol. It occurs in yeast and bacteria, but also in oxygen-starved human muscle cells. Fermentation is used by humans to make beer and food, like kimchi. Fermentation is a form of anaerobic digestion that generates ATP by the process of substrate-level phosphorylation. Summarize what occurs during the three steps of cellular respiration and indicate where each process takes place in the cell. (6 points) Glycolysis: It is a process that occurs in the cytoplasm. It converts each molecule of glucose to two molecules of pyruvic acid. It refers to an anaerobic process that proceeds whether or not oxygen is present or not. The pyruvic acid diffuses into the inner compartment of the mitochondrion where a transition reaction occurs that starts to prepare pyruvic acid for the next stage of respiration. Krebs cycle-This is...
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...ml) to measure fermentation rates by pressure, what amount of yeast will ferment the fastest? Hypothesis: If yeast (Saccharomyces cerevisiae) is placed within a test tube of 10 ml of 5% glucose solution in varying amounts (10 ml, 20 ml, and 30 ml) to measure fermentation rates by pressure, then 30 ml will ferment the fastest because there will be more yeast to undergo fermentation; producing more carbon dioxide. Analysis: There are two types of cellular respiration (CR), there is aerobic and anaerobic. Aerobic CR requires the cell to contain a mitochondrion and the presence of oxygen. Aerobic CR will produce around 38 molecules of ATP per glucose molecule. Anaerobic CR works without oxygen or a mitochondrion, but will only produce 2 molecules of ATP. Anaerobic CR requires NAD+ to convert into NADH. When the cell creates too much NADH and is running low on NAD+ it undergoes fermentation....
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...important chemical reactions such as enzyme catalysis. And enzymes are used in medical field for making so many important medicines like antibiotics. Fermentation process using enzyme is an important thing in alcoholic beverages. In food and digestion Enzymes allow multiple chemical reactions that occurring in any second in the body of animals and plants. The enzymes allow the transformation of food into energy and facilitate variety of other important biological functions. Human enzymes meet one of the three fundamental functions. The largest of every types of enzymes, sometimes called metabolic enzymes, it helps in so many basic body processes, from breathing to thought. Some of this enzymes are dedicated to the maintenance of immune system , they protects from the diseases and others helps to control the effect of toxins like tobacco smoke transforming them into a form , body will eject it more easily. A second category of enzymes is in diet and it consist enzymes in raw foods that help in...
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...Fermentation, Good or Bad? The topic that connects all three of these articles together is the current and ongoing research of the uses of microbes in food and for nutrition purposes. Food microbiology is the study of microorganism inhabit, create, or contaminate food. Food microorganisms can be found in a various amount of ways. These microorganisms can be natural or they can be genetically modified organisms. There are also good natural microbes and bad natural microbes that we can find in the foods that we eat. It is being questioned as to whether fermented foods are okay to eat. The thought of fermented foods freaks a lot of people out. The problem with microbes, is that most people only think of the harmful disease causing microbes,...
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...Study of Pineapple Peelings Processing into Vinegar by Biotechnology ABSTRACT | This study aimed to reduce post-harvest losses of pineapple local variety egbenana by the transformation of juice into vinegar through biotechnological process.Vinegar was produced through two successive fermentations: alcoholic and acetic fermentations. The alcohol fermentation was carried out at 30°C using yeast. Biomass, pH and Brix were evaluated daily during the fermentation. Acetic fermentation was carried out at 30°C using an acetic bacteria strain isolated from pineapple wine previously exposed to ambient temperature (28°C) for 5 days. Biomass, pH and acid levels were monitored each 2 days. The performance of acetic bacteria isolated was also assessed by studying their glucose and ethanol tolerance. The study allowed the isolation of yeast coded Saccharomyces cerevisiae (LAS01) and an acetic bacteria coded Acetobacter sp. (ASV03) both occurring in the pineapple juice. The monitoring of successive fermentations indicated that the pineapple juice with sugar concentration of 20 Brix, seeded with 106 cells of Saccharomyces cerevisiae (LAS01) for alcoholic fermentation for 4 days and afterwards seeded with 106 cells of Acetobacter sp. resulted in 4.5 acetic degree vinegar at Brix 5.3% and pH 2.8 for 23 to 25 days. The study of glucose tolerance of the strain of Acetobacter sp. showed that the growth of acetic bacteria was important in a juice with high concentration of sugar. However, the concentration...
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...experimentation with yeast fermentation and its gas production when exposed to different carbohydrates, such as sucralose, sucrose, starch, fructose, and glucose. The main hypothesis, which was the simpler the carbohydrate the yeast was exposed to, the faster the rate of fermentation, was supported. The liquids containing simpler carbohydrates produced a larger amount of carbon dioxide gas, which allowed a bigger change in the height of the gas bubble. This suggests that there was a high rate of fermentation for simpler carbohydrates. Each liquid containing complex carbohydrates produced a smaller change in the gas bubble height as a result of low carbon dioxide gas production. This suggested that there was a slower rate of fermentation for complex carbohydrates. Further experimentation could be done by replicating the experiment including different juices and carbohydrate complexities to provide support for this hypothesis. The hypothesis for the respirometer...
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...that happen within the cell. By definition there are many kinds of metabolisms aerobic respiration, anaerobic respiration and fermentation. Aerobic respiration is the process of breakdown of glucose to produce ATP, which requires presence of Oxygen. Aerobic respiration involves four steps glycolysis, formation of acetyl coenzyme A, the citric acid cycle and electron transport chain. Two enzymes that indicate the presence of electron transport chains (ETCs) are oxidase and catalase. Oxidase is an enzyme that is found in Cytochrome C of ETC. It is found in bacteria and mitochondria of eukaryotic organisms. Organism that possess ETC with directly move electrons to oxygen, which is the final electron acceptor. Catalase is common enzyme, which is found in living organisms. Catalase is very important enzyme that protects cell from hydrogen peroxide; it is very damaging to the cell. Catalase decomposes hydrogen peroxide, into harmless water and oxygen gas. To avoid death cells produce catalase, this results from faulty ETC. Anaerobic respiration occurs in environments without oxygen gas. Anaerobic respiration only occurs in prokaryotic organisms;...
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...Photosynthetic Stages Joe Alanis BIO/204 March 19, 2016 Cynthia Collins-Clausen Explain how CO2 enters leaves. What environmental factors control stomatal movement? How are these factors related to physical and chemical properties that control the opening and closing of stomata? CO2 is capable of entering into the leaves from very tiny pores located under the leaf called “stomata”, where it is then used to help synthesize carbohydrates from light energy. When the process ceases and the plant respires it leaves simultaneously. Environmental factors that could have an effect on stomatal movement would be the variation of how much light is being absorbed by the plant. As the plant is absorbs sunlight, stomata absorb the CO2 through their pores which allows for the process of photosynthesis to start. When light energy is no longer available the stomata closes therefore releasing the CO2 that was absorbed. What are primary stages in the photosynthetic carbon reduction (PCR) cycle? Explain the role of each stage. Draw a diagram of the stages by utilizing drawing tools in Microsoft Word to aid your explanation. There are three stages of the photosynthetic carbon reduction (PCR) cycle: Step 1 Carboxylation reaction CO2 + RUBP Results is 3-PGA catalized by enzyme RUBISCO; does not require energy Step 2 Reduction of 3-PGA to GAP Removes the first product of carboxylation (3-PGA) and facilitate CO2 uptake here it requires ATP and NADPH Step 3 One 3-carbon sugar...
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...The Role of Polysaccharides and Monosaccharides in Metabolism and Their Rate of Carbon Dioxide Produced During Fermentation Abstract Fermentation is the metabolization of sugars with carbon dioxide being produced as a result. Using yeast to ferment different types of sugars, we tested the rate of carbon dioxide production. Our findings of sucralose producing a slower rate of carbon dioxide than glucose during fermentation, are supported by the fact that polysaccharides are harder to break down than monosaccharides. Polysaccharides are complex sugars, or chains of monosaccharides, so they are harder and take longer to be broken down and metabolized. Introduction Glycemic Index is described by how fast your body converts the carbohydrates...
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...UNIT 24: BREWING SCIENCE Get assignment help for this unit at assignmenthelpuk@yahoo.com LO1 Understand fermentation systems Microbial groupings: microbial range and form Unicellular fungi: importance to the fermentation process especially Saccharomyces species History of fermentation advances: metabolic pathways of respiration; dynamics of anaerobic respiration/fermentation; methods of controlling fermentation (top and bottom); principal steps in the brewing process LO2 Understand the biochemistry of malting, mashing and conversions in the copper Barley physiology: choice of cereal; biochemical changes affected by the malting process Wort composition: biochemical/biophysical conversions Malting process: the enhancement of diastatic power; control of N2-content; development of colour Mashing process: the ionic balance of the liquor (Burtonization); factors affecting extraction and enzymatic conversion in the grist; importance of temperature and time controls; monitoring ‘run-off’ from the mash tun for turbidity and specific gravity Hop variety: varieties of hops available (including brief histories and geographical location); characteristic properties of each variety; hop additions to brews (biochemistry of action); hop quality (appearance, feel and aroma) Hop biochemistry: the ratio of α and β-acids; oxidative conversions to humulones and hulupones; the effect of seed content on hop property and the principle contributors to aroma The copper: inactivation of enzymes; precipitation...
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...Bacteria are distributed throughout the world in almost every conceivable habit. Bacteria are unicellular microorganisms, with variable shapes and nutritional needs. They lack a distinct nucleus and occur singly or in chains or clusters and form distinct colonies. Bacteria are classified on the basis of many characteristics. Morphological and physiological features such as cell shape, motility, formation of spores and other distinguishable structures, and reaction to Gram stain is a good start in identifying bacteria. Other staining techniques such as Acid Fast stain are also useful in determining species. More important in identification of a genus and species of bacteria are biological tests, including the determination of the types of nutrients a cell can use, the products of its metabolism, and the response to specific chemicals. Other factors that can assist in identification of bacteria are their ecological habitats and more advanced methods such as genetic and molecular composition. Using various techniques one is able to distinguish and ultimately assign then genus and species of the unknown bacteria. Methods: Gram Staining: The Gram stain separates bacteria in two distinct classes and is also useful in distinguishing morphology. Through this technique one is able to identify bacteria as either gram positive or gram negative. The gram-negative bacteria have thin peptidoglycan layers that do not hold the primary stain, rather...
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...Rate of Fermentation (How Yeast Get Energy) Purpose: To study how the rate of fermentation by yeast cells is affected by the concentration of molasses. You will be using yeast cells (microscopic organisms) and molasses (a product of photosynthesis in sugar cane). You will measure the rate of fermentation by measuring how much carbon dioxide (CO2) is given off by the yeast cells over a certain period of time. Materials Goggles 6 test tubes (18mm x 150 mm, for example), rimless is best 6 test tubes (10mm x 75 mm, for example), rimless is best 50 mL graduated cylinder Medium sized beaker (for waste) Test tube rack Metric rule 6 little squares of aluminum foil (about 4 cm by 4 cm) 100 mL beaker with 50 mL of 25% molasses solution 20 mL of yeast suspension Dropper Marking pen Masking tape Introduction to the Student Even cells as small as yeast cells need to obtain the energy to carry out life processes. Because yeast cells are so small, they do not require as much energy from their food as large multicellular organisms do. Yeast use a process called fermentation. What is fermentation? Fermentation is a way for cells to get energy without using oxygen. Small organisms can break down complex organic substances such as sugar into simpler ones and release the energy that is in the carbon-carbon bonds. The waste products of this process are molecules such as ethyl alcohol and lactic acid, as well as other. Human beings have...
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