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Determination of sodium and potassium in honey samples by atomic absorption spectrometry
Venclová, Veronika ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This bachelor thesis was focused on the determination of sodium and potassium in honey samples by atomic absorption spectrometry with a flame atomization technique. An acetylene-air flame was used. Prior to the analysis of the honey samples, the optimal working parameters of the used method were found. The optimized parameters were: the height of the beam above the burner, the flow rate of acetylene, and the burner's horizontal position. Under the optimal conditions, the basic characteristics of the determination of sodium and potassium were studied. Sodium and potassium concentrations in the honey samples were determined under optimal conditions. A total number of 27 honey samples were analyzed. The sodium content ranged from 0.880 to 25.3 mg/kg. The potassium content was in the range of 223 - 2750 mg/kg. In the end, the measured concentrations of honey samples originating from the Czech Republic were compared with the foreign studies. Keywords Potassium, sodium, honey, atomic absorption spectrometry, flame spectrometry
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Application of spectral and non-spectral analytical methods for monitoring the quality of ketchups
Havlíčková, Barbora ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
The aim of the master´s thesis was to verify the applicability of elemental analysis and molecular spectrometry for examining the authenticity of ketchup. For verify of share refractometric dry matter introduced into ketchup from tomatoes was used analysis of potassium and lycopene content. Ketchups with different tomato contents were prepared and subsequently models were created, which were used to verify the proportion of refractometric dry matter introduced into tomato ketchup in ketchups from the store. The results of the work showed that the amount of lycopene is a problematic marker for verifying the authenticity of ketchup, because during the production of ketchup, lycopene is degraded.In contrast, the amount of potassium in ketchup has been shown to be a good marker for monitoring the authenticity of ketchup. The model based on the potassium content of ketchup worked reliably, the deviations obtained from the quantity of tomatoes used for the production of ketchup indicated on the packaging were less than 10%. Higher deviations were achieved in ketchups with a minimum permitted tomato content of up to 20%. The concentration of potassium in ketchup with a lower content of used tomatoes can be significantly affected by the addition of other ingredients to the ketchup (onion, garlic, carrot, apple, etc.). In addition to the ketchup production technology used, the ripeness of tomatoes also has a significant effect on the model for verifying the authenticity of ketchup.
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Mechanisms of exodermal response to nutrient availability in the environment
Gargoš, Ondřej ; Tylová, Edita (advisor) ; Kummerová, Marie (referee)
in English The apoplastic barriers of the root (endodermis and exodermis) represent an important regulatory mechanism for the uptake of water and nutrients from the environment, ensuring its selectivity. In addition, both layers respond to stress factors by altering its rate and degree of cell wall modification, which affects the transport properties of the root and represents adaptive plants to high heterogeneity of the soil environment. Apoplastic barriers also respond to the availability of mineral nutrients. This issue has recently been intensively studied and a number of ambiguities persist. Interestingly, the deficiency of some mineral nutrients stimulates the differentiation of barriers, while the deficiency of other mineral nutrients delays the differentiation. In addition, different plant species react differently to the deficiency of the same element. Another interesting aspect is the fact that the reaction of the endodermis and exodermis is localized and takes place mainly in that part of the root system which is directly exposed to the stress factor. This phenomenon has been observed with cadmium toxicity, but more recently with local nutrient deficiencies (nitrogen and potassium) in Zea mays. This diploma thesis deals with the functional significance of localized enhancing or delaying...
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Simulation of processes in cellular membranes
Melcr, Josef ; Jungwirth, Pavel (advisor)
Simulation of processes in cellular membranes Abstract Many important processes in cells involve ions, e.g., fusion of synaptic vesi- cles with neuronal cell membranes is controlled by a divalent cation Ca2+ ; and the exchange of Na+ and K+ drives the the fast electrical signal transmis- sion in neurons. We have investigated model phospholipid membranes and their interactions with these biologically relevant ions. Using state-of-the-art molecular dynamics simulations, we accurately quantified their respective affinites towards neutral and negatively charged phospholipid bilayers. In order to achieve that, we developed a new model of phospholipids termed ECC-lipids, which accounts for the electronic polarization via the electronic continuum correction implemented as charge rescaling. Our simulations with this new force field reach for the first time a quantitative agreement with the experimental lipid electrometer concept for POPC as well as for POPS with all the studied cations. We have also examined the effects of transmembrane voltage on phospholipid bilayers. The electric field induced by the voltage exists exclusively in the hydrophobic region of the membrane, where it has an almost constant strength. This field affects the structure of nearby water molecules highlighting its importance in electroporation. 1
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Determination of selected elements in potato tubers by atomic absorption spectrometry
Fořtová, Lucie ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
The main aim of this bachelor thesis was a determination of the elements K, Mg, Ca, Na, Zn and Fe in the potato tubers and in their boiled solution using the method of flame atomic absorption spectrometry. The chosen samples were late consumer potato tubers of Granada cultivar (boiling type B). It was necessary to optimize working conditions before the sample analysis. The optimal flow rate of acetylene ranged from 2.0 to 2.5 l/min using the flame acetylene-air. The flame acetylene-nitrous oxide was used only for calcium with flow rate 6.0 l/min. The optimal height of a beam above the burner edge was measured in interval 5 to 7 pieces of defined scale mentioned in a manual for spectrometer GBC 933 AA. Using the optimal conditions, the basic characteristics for individual methods of determination were characterized (LOD, LOQ, LDR, sensitivity, repeatability). Limits of quantification were following: 78, 31, 7.0, 8.0, 190 and 71 μg/l for K, Na, Mg, Ca, Fe and Zn, respectively. The optimal conditions were used for the determination of the selected elements in samples. The solutions were prepared from diversely processed potato tubers (whole, whole without skin, chopped without skin, skin) by boiling into deionized water. After the samples had cooled down, the concentrated nitric acid was added...
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Function of the AtKUP5 transporter in Arabidopsis thaliana
Štočková, Hana ; Tylová, Edita (advisor) ; Hála, Michal (referee)
Potassium is one of the essential elements necessary for plant growth. It is involved in many plant processes, such as osmoregulation, enzymes activaton, etc. These functions are very often closely related to its transport in the cell and the whole plant. Although potassium is abundant in earth's crust, the mount of plant-available form is often insufficient. Potassium deficiency manifests itself on many levels and also contributes to the reduction of yield and quality of agricultural crops. There are many of potassium-transporting proteins in the plant. One of the important families of potassium transporters is the KT/HAK/KUP family. This family includes, among others, the high-affinity transporter HAK5, which is key for the uptake of potassium from the environment with low-potassium availability. One of the not very characterized transporters from the KT/HAK/KUP family is the KUP5 transporter, which I deal with in my diploma thesis. The aim of this work is to analyze the phenotypic manifestations of kup5 T-DNA insertion mutants and to characterize the functions of the transporter KUP5 in Arabidopsis thaliana plants. I analyzed the growth of kup5 insertion mutants in various environmental conditions and performed plant transformation to determine the localization of the KUP5 transporter in the...
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Simulation of processes in cellular membranes
Melcr, Josef ; Jungwirth, Pavel (advisor)
Simulation of processes in cellular membranes Abstract Many important processes in cells involve ions, e.g., fusion of synaptic vesi- cles with neuronal cell membranes is controlled by a divalent cation Ca2+ ; and the exchange of Na+ and K+ drives the the fast electrical signal transmis- sion in neurons. We have investigated model phospholipid membranes and their interactions with these biologically relevant ions. Using state-of-the-art molecular dynamics simulations, we accurately quantified their respective affinites towards neutral and negatively charged phospholipid bilayers. In order to achieve that, we developed a new model of phospholipids termed ECC-lipids, which accounts for the electronic polarization via the electronic continuum correction implemented as charge rescaling. Our simulations with this new force field reach for the first time a quantitative agreement with the experimental lipid electrometer concept for POPC as well as for POPS with all the studied cations. We have also examined the effects of transmembrane voltage on phospholipid bilayers. The electric field induced by the voltage exists exclusively in the hydrophobic region of the membrane, where it has an almost constant strength. This field affects the structure of nearby water molecules highlighting its importance in electroporation. 1
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Potassium in plant osmoregulation
Kholová, Kateřina ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Potassium is very mobile in plants and is transported across membranes using transporters and channels. It is present in the ionic form K+ in plants. Also, in the form of this ion, K+ is taken up by plants from the soil solution. The uptake is mediated by the transporter HAK5 and by the channel AKT1. The transfer of K+ to the xylem is provided by the channel SKOR and the transporter KUP7. The role of potassium as an osmotically active element is crucial. K+ helps to regulate the amount of water in the cells and thus to maintain the turgor. Turgor is important for maintaining the shape of the plant cells and for its growth. Stomatal guard cells are used as a model system for describing processes related to the K+ osmotic function. Movement of K+ is involved in the regulation of opening and closing of stomata on the principle of turgor changes. Transport of K+ into guard cells is provided by channels KAT1, KAT2, AKT1 and AKT2. On the contrary, K+ release is mediated by the channel GORK on the plasma membrane and TPK1 on the tonoplast. K+ supports also the transport of assimilates in the phloem, where the channel AKT2 plays a role. The osmotic functions of K+ are the main topic of this bachelor thesis, which summarizes current knowledge about transport mechanisms necessary for the function of K+ as osmotically...
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Simulation of processes in cellular membranes
Melcr, Josef ; Jungwirth, Pavel (advisor) ; Otyepka, Michal (referee) ; Tarek, Mounir (referee)
Simulation of processes in cellular membranes Abstract Many important processes in cells involve ions, e.g., fusion of synaptic vesi- cles with neuronal cell membranes is controlled by a divalent cation Ca2+ ; and the exchange of Na+ and K+ drives the the fast electrical signal transmis- sion in neurons. We have investigated model phospholipid membranes and their interactions with these biologically relevant ions. Using state-of-the-art molecular dynamics simulations, we accurately quantified their respective affinites towards neutral and negatively charged phospholipid bilayers. In order to achieve that, we developed a new model of phospholipids termed ECC-lipids, which accounts for the electronic polarization via the electronic continuum correction implemented as charge rescaling. Our simulations with this new force field reach for the first time a quantitative agreement with the experimental lipid electrometer concept for POPC as well as for POPS with all the studied cations. We have also examined the effects of transmembrane voltage on phospholipid bilayers. The electric field induced by the voltage exists exclusively in the hydrophobic region of the membrane, where it has an almost constant strength. This field affects the structure of nearby water molecules highlighting its importance in electroporation. 1
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Influence of the pre-analytical phase on glucose and potassium blood examination
ČERNÁ, Iva
This bachelor thesis deals with the stability of glucose and potassium in blood. The main objective of this work was to test the stability of both analytes with regard to the prolonged time from sampling to separation and the temperature conditions of sample storage before the actual analysis. For glucose, stability was tested in two different materials, both in serum and plasma, with the addition of a glycolysis inhibitor.
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