Spectrophotometry, Glucose And Glycosylated Hemoglobin

The correct answer is "Distance between two successive peaks and expressed in terms of nanometers." Wavelength refers to the distance between two successive peaks in a wave. It is commonly measured in nanometers, especially in the context of electromagnetic waves such as light.

The answer is correct because wavelength, frequency, and energy are all related to each other. Wavelength is the distance between two consecutive points on a wave, frequency is the number of wave cycles that pass a given point in one second, and energy is directly proportional to the frequency. Therefore, when the wavelength is shorter, the frequency increases, and as a result, the energy also increases.

LASER stands for Light Amplification by Stimulated Emission of Radiation. This acronym accurately describes the process by which a laser beam is generated. In a laser, light is amplified through stimulated emission, where photons are emitted from excited atoms or molecules, causing a chain reaction of emission. This process produces a coherent, monochromatic, and intense beam of radiation. The other options in the question are incorrect because they do not accurately describe the process of light amplification in a laser.

Cortisol is synthesized in the adrenal glands, not in the pancreas. The pancreas is responsible for synthesizing and secreting hormones such as glucagon, insulin, and somatostatin, which are involved in regulating blood sugar levels and digestion. Cortisol, on the other hand, is a steroid hormone produced by the adrenal glands and plays a role in regulating metabolism, immune response, and stress.

The correct answer is 75 grams because the World Health Organization (WHO) recommends a standard glucose load of 75 grams. This is commonly used in various medical tests, such as the oral glucose tolerance test, to assess a person's ability to metabolize glucose and diagnose conditions like diabetes. The 75-gram glucose load is considered to be a standard amount that provides accurate results for diagnosing and monitoring glucose metabolism.

This statement suggests that one of the distinguishing features of type 1 diabetes is the absence of autoantibodies. Autoantibodies are antibodies that mistakenly target and attack the body's own cells and tissues. In type 1 diabetes, these autoantibodies are typically present and contribute to the destruction of insulin-producing beta cells in the pancreas. Therefore, the presence of autoantibodies is a characteristic feature of type 1 diabetes, making the statement "Autoantibodies (-)" incorrect.

The given statement is true for all the options except for the hydrogen lamp. While the other three options (deuterium lamp, tungsten lamp, and silicone carbide) emit light in the UV, visible, and infrared regions respectively, the hydrogen lamp emits light in the UV region, not the infrared region.

The end result of the Neocuproine method is the formation of a Cuprous-Neocuproine yellow complex. This complex is formed when neocuproine, a chelating agent, reacts with cuprous ions. The yellow color of the complex is due to the absorption of light in the visible spectrum. This method is commonly used for the determination of cuprous ions in solution.

Random blood sugar testing does not require fasting. This means that a person can have food or drink before the test without affecting the results. Therefore, the correct answer is 0 hours, indicating that no fasting is needed for this type of blood sugar test.

To accurately measure absorbance, the bandpass of the spectrophotometer should be narrower than the natural bandpass. A narrower bandpass allows for more precise measurement of the specific wavelengths being absorbed by the sample. A bandpass that is less than 1/5 of the natural bandpass would be ideal for accurate absorbance measurement.

After an oral glucose tolerance test (OGTT), the plasma glucose levels are expected to rise and then gradually decrease over time. The correct answer states that after 2 hours, the plasma glucose levels should be 40-70 mg/dL above the fasting level. This means that after 2 hours, the glucose levels should still be elevated but not as high as the levels at 30 minutes or 1 hour. This is a normal response to the OGTT, as the body takes time to process and metabolize the glucose.

The hexokinase method is a reference method for measuring glucose levels. It is based on the enzyme hexokinase, which catalyzes the conversion of glucose to glucose-6-phosphate. This method is widely used in clinical laboratories due to its accuracy and precision. It involves the measurement of the NADPH produced during the reaction, which is directly proportional to the glucose concentration. The hexokinase method is considered a reliable and standardized technique for glucose measurement, making it the correct answer in this context.

Glucose does not contain an active ketone or aldehyde group, which is why it is the only carbohydrate that can be directly used for energy or stored as glycogen. The presence of a double bond and a negative charge in the enol anion makes glucose an active reducing substance. Additionally, the brain relies entirely on blood glucose for energy production.

Mutarotase is the correct answer because it is an enzyme that catalyzes the interconversion of alpha-D glucose and beta-D glucose. In this case, it converts alpha-D glucose to beta-D glucose as part of the glucose oxidase reagent. The other options, peroxidase, glacial HAC, and hydrogen peroxide, are not involved in the conversion of glucose and are therefore not the correct answer.

The correct answer is "Reduction of a yellow ferricyanide to a colorless ferrocyanide by glucose". In the Hagedorn Jensen method, inverse colorimetry is used to measure the concentration of glucose in a solution. In this method, a yellow ferricyanide is reduced to a colorless ferrocyanide by glucose. The reduction reaction causes a change in color, which can be measured using a colorimeter or spectrophotometer. By measuring the change in color, the concentration of glucose can be determined.

The given options are all different terms used to refer to a cuvet, which is a small transparent container used in spectrophotometry to hold samples for analysis. "Sample cell," "absorption cell," and "analytical cell" are all commonly used terms to describe a cuvet, while "adsorption cell" is not typically used to refer to a cuvet.

Glycosylated hemoglobin, also known as HbA1c, is a form of hemoglobin that has glucose molecules attached to it. It is used as a marker to determine the average blood glucose level over the past 2-3 months. The correct answer states that the largest subfraction of normal hemoglobin A in diabetic individuals only is not glycosylated. This means that in diabetic individuals, the largest subfraction of normal hemoglobin A is not affected by the attachment of glucose molecules. Therefore, this subfraction does not contribute to the measurement of HbA1c levels in diabetic individuals.

Beer's Law states that the concentration of a substance is directly proportional to its absorbance. However, the given answer states that the concentration of the unknown is proportional to the inverse log of transmittance. This is incorrect because Beer's Law does not involve the inverse log of transmittance. Instead, it relates the concentration of a substance to its absorbance.

The Holmium oxide filter is used to check the wavelength indicated on the device. This filter is specifically designed to emit light at specific wavelengths, which can be used as a reference to verify the accuracy of the device's wavelength indication. By comparing the device's indicated wavelength with the known wavelength emitted by the Holmium oxide filter, any discrepancies or inaccuracies in the device's wavelength indication can be identified and corrected.

The black top is the correct answer because it is referring to the color of the top of the container or tube. In laboratory settings, different colored tops are often used to indicate the type of additive or anticoagulant present in the container. In this case, the black top is likely indicating the use of buffered sodium citrate as an additive.