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Explain why the TSI medium contains a lower concentration of glucose than of lactose and sucrose?
When any sugar is metabolized under anaerobic conditions (fermentation), there is increased acid production; thus the butt of the tube remains acid for a longer period of time. When glucose only is fermented, acid is produced throughout the medium but due to the relatively low concentration of glucose in the medium and the aerobic metabolism that is present on the slant, nitrogenous metabolic end products soon change the reaction of the slant to alkaline. These alkaline products neutralize the small amounts of acids present in the slant but are unable to neutralize the large amounts acid present in the butt. Thus, the appearance of an alkaline (red) slant and an acid (yellow) butt after 24 hours incubation indicates that the organism is a glucose fermenter but is unable to ferment lactose and sucrose. Bacteria that ferment lactose or sucrose (or both), in addition to glucose, produce such large amounts of acid that the oxidative deamination of protein that may occur in the slant does not yield enough alkaline products to cause a reversion of pH in that region. Thus, these bacteria produce an acid slant and acid butt. The inclusion of sucrose permits separation of certain Proteus organisms which ferment sucrose from the salmonellae since both of these groups of organisms are lactose-negative and both may produce hydrogen sulfide.
AC
What else can I help you with?
What monosaccharides make up lactose?
Lactose is composed of two monosaccharides: glucose and galactose.
Why is the lac operon not transcribed when both glucose and lactose are present in the medium?
The lac operon is not transcribed when both glucose and lactose are present because glucose is the preferred energy source for the cell. When glucose is available, the lac operon is repressed, preventing the cell from wasting energy by metabolizing lactose.
What is the chemical equation for lactose and lactase?
The chemical equation for the breakdown of lactose by lactase is: C12H22O11 (lactose) + H2O → C6H12O6 (glucose) + C6H12O6 (galactose). Lactase is the enzyme that catalyzes this reaction, breaking down lactose into its constituent monosaccharides, glucose, and galactose. This process is essential for the digestion of lactose in individuals who are lactose intolerant.
What is the combination of glucose and galactose?
The combination of glucose and galactose forms lactose, which is a disaccharide commonly found in milk. Lactose is broken down by the enzyme lactase into its constituent monosaccharides during digestion.
Name two disaccharides and list the monosaccharides that comprise them.?
Lactose is comprised of glucose and galactose. Sucrose is comprised of glucose and fructose.
Why does lactose-free milk turn up as positive on a glucose strip?
lactose and glucose are not the same! milk contains sugar, and sugar (starch-->glucose) is glucose, so if the milk is lactose free, it still contains glucose and proteins...
Does milk have glucose and why?
Milk contains lactose, which is a disaccharide composed of glucose and galactose. Lactose is broken down by the enzyme lactase in the body into its monosaccharide components, glucose and galactose, which can then be absorbed into the bloodstream.
Is glucose in lactose free milk?
Yes, lactose-free milk contains glucose, but it is not present in its original form. Lactose, the sugar found in regular milk, is a disaccharide composed of glucose and galactose. In lactose-free milk, the enzyme lactase is added to break down lactose into its constituent sugars, glucose and galactose, making it easier for people with lactose intolerance to digest. Thus, while lactose itself is absent, glucose is a result of the breakdown process.
Why did the glucose level of the whole milk increase after putting in lactase?
The glucose level of whole milk increased after adding lactase because lactase is an enzyme that breaks down lactose, the sugar present in milk, into its simpler components, glucose and galactose. When lactase is introduced, it catalyzes the hydrolysis of lactose, resulting in the release of glucose, thereby increasing the overall glucose concentration in the milk. This process effectively converts the lactose into more readily absorbable sugars, which can be beneficial for individuals who are lactose intolerant.
Why is milk sweet in taste?
That's because the lactose is broken down into two other easily digested sugars which are sweeter: breaks into galactose and glucose... this occurs through hydrolysis in the milk prior to drinking it ( because lactase is found in the milk, which contains lactose), thus creating a sweeter milk).
What Disaccharide is produced by combining glucose and galactose?
Lactose is the disaccharide produced by combining glucose and galactose.
Does coke have lactose in it?
Cola is lactose free it has no lactose it has glucose in it !
How would expect the amount of glucose in soy milk change after treatment with lactase?
After treatment with lactase, the amount of glucose in soy milk is expected to increase. Lactase is an enzyme that breaks down lactose, the sugar found in milk, into glucose and galactose. While soy milk is typically lactose-free, if any lactose is present or if the treatment is applied to a dairy milk alternative, the lactase would convert it into glucose, resulting in a higher glucose concentration.
How is glucose an important factor in lactose synthesis?
Glucose is important for lactose synthesis because it provides the substrate for the enzyme lactose synthase to combine with galactose to form lactose. Without glucose, there would not be enough substrate available for lactose synthesis to occur efficiently. Additionally, glucose can stimulate the production of lactose synthase enzyme, further promoting lactose synthesis in mammary glands.
What monosaccharides make up lactose?
Lactose is composed of two monosaccharides: glucose and galactose.
Word equation for lactase hydrolyze lactose into glucose?
Lactase catalyzes the hydrolysis of lactose into glucose and galactose. This process can be represented by the following word equation: Lactose + Water → Glucose + Galactose.
Which enzyme catabolyzes lactose sugar into monosacharides?
lactase breaks down lactose into glucose and glucose monomers.
