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The role of mitochondrial metabolism in initiation and adaptation to hypoxic conditions.
Rohlenová, Terezie ; Novák, Petr (advisor) ; Rohlena, Jakub (referee)
We can meet pathological hypoxia in the cases of hearth attack, ischemic stroke, but also during tumor invasion, thanks to insufficient angiogenesis. The activation of HIF- 1 factor during hypoxic conditions is crucial for the cell survival. This factor modulates energetic metabolism in favor of fast progressing glycolysis (with the contribution of glutaminolysis) which provides to cell enough ATP and "building blocks", while suppressing Krebs cycle and respiration because of shortage of oxygen. The thesis studies energetic metabolism of HepG2 cells (derived from liver carcinoma) which are cultivated in the media with various energetic substrates, i. e. glucose or galactose (always together with glutamine and pyruvate) under the hypoxic conditions (5% O2). HepG2 cells use particularly oxidative metabolism for ATP and "building blocks" production under the normoxic conditions while hypoxic environment causes metabolic shift in glycemic condition. Interestingly, cells cultured in galactose (glutamine) didn't switch the energy metabolism from oxidative to aerobic glycolysis such as cells cultivated in glucose, although HIF-1 factor was stabilized. We found that enhanced activity and integrity of mitochondria, enhanced maximal capacity and reserve capacity of respiration chain correlates with...
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The effect of biotic stress on the metabolism of saccharides in tobacco plants (Nicotiana tabacum L.)
Kloudová, Kateřina ; Ryšlavá, Helena (advisor) ; Tichá, Marie (referee)
Plants have developed a number of ways how to minimise negative influence of the environment. As a consequence of stress action, plants carbohydrate metabolism is quite often influenced, esp. on the level of expression and activities of different enzymes and also several metabolites concentration. One of key enzymes of carbohydrate metabolism is invertase. The aim of this work was to find out, whether the activity of its isoforms (cytoplasmic, vacuolar and extracellular) in tobacco plants is influenced by Potato virus Y (PVY). It was shown, that activity of cytoplasmic invertase was not affected, but the activity of vacuolar and extracellular isoform was enhanced during potyviral infection. Hence, it is likely, that vacuolar and extracellular invertases are related to plant antiviral defence. The effect of PVY on other enzymes of carbohydrate metabolism and several metabolites content was studied. Activity of α-amylase and phosphorylase, starch-degrading enzymes, was strongly enhanced during potyviral infection. That is probably how plant cells get glucose, which is a key source of energy and metabolites for biosynthesis of different compounds. It may also serve as a signal molecule. Activity of other hydrolytic enzymes, β-glucosidase and β-hexosaminidase, was also slightly increased. There was no...
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Optimization of HPLC-ELSD method for determination of sugars in foods
Laba, Marija ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master's thesis deals with the optimalization of HPLC-ELSD method for the determination of carbohydrates in food. The theoretical part focuses on the classification and characterization of carbohydrates, the occurrence of carbohydrates in food and their physiological importance. There was targeted mainly glucose, fructose, sucrose and maltose. There is a brief summary of the analytical methods that can be used to determine carbohydrates. Experimental part is based on a literary review. It also deals with high performance liquid chromatography with evaporative light scattering detector. The main content in this part is the optimalization of condition for reliable and rapid separation of the most frequently occurring carbohydrates in foods. The carbohydrates were identified and quantified under optimum condition in real samples specifically in fruit juice, beer, ketchup and red pepper powder. The result is commented in conclusion.
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Chromatographic determination of simple sugars in selected beverages
Jurečková, Zuzana ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
An important part of the drinks are simple carbohydrates, because this thesis focuses on this issue. The theoretical part describes the characteristics , production , metabolism and the use of simple carbohydrates such as glucose, fructose and sucrose. There is also the definition of drinks and their main divisions . The literature review is based on the experimental part of analyzing selected beverages by high performance liquid chromatography with refractometric detection coupled to columns or alkyl ion-exchange phases. In conclusion, the results were compared to determine and comment . Nowadays the emphasis is on the correct functioning of the digestive tract. An important factor that supports the intestinal microflora is a prebiotic carbohydrate - tagatosa This could become tagatosa whose properties , production, metabolism in the body and any use is also included in the search . In the experimental part is listed possible optimization analysis of samples containing tagatosy on both types of columns in the HPLC system. The result is again commented in conclusion.
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Sledování změn sacharosy v nápojích
Polesová, Denisa
The Master thesis was made at Department of Post-Harvest Technology of Horticulture Faculty of Mendel University in Brno in 2012/2014.The thesis is devided into the two parts, theoretical and experimental part. First of all I classified and described beverages and carbohydrates which is the theoretical part of the thesis. Next chapters describe individual form of carbohydrates, natural and artificial as well which occur in beverages. Apart of this, I also introduced its properties, occurrence, importance and possible methods of analysis.A great deal of attention of this thesis is given to the experimental part which is concentrated on speed of decomposition of sucrose in different pH, thus influence of action of citric acid and oxalic acid, which were mixed up in concentrations 1 and 5 %. The decomposition was also observed in fruit juices.The methods used for subsequent determination of carbohydrates were method of Luffa-Schoorla and enzymatic determination of carbohydrates with using of set K-SUFRG Megazyme.Efficiently operated inversion acids, mainly oxalic acid.
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Sweeteners (natural and artificial) used in the food industry
PIHLÍK, Pavel
The aim of this work is to introduce the sweeteners which are used in the food industry in the Czech Republic but also in the world. The basic sweetener which is a measure of the other sweeteners is regarded as sugar (sucrose). In this bachelor´s work, I described the history of the production of beet sugar in the Czech Republic, the products which are made of it and also its usage in food industry. Furthermore, I introduce the basic types of sweeteners by which we try to replace the beet sugar. I describe the history, production, characteristics and their usage. These are mainly the natural sweeteners which are divided into the carbohydrate (sucrose, fructose, glucose, honey, lactose and sugar alcohols), non-carbohydrate (stevioside, thaumatin) and artificial align (aspartame, saccharin, cyclamates, acesulfame-K, sucralose).
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