biology
Pre-Lab 1 Assignment
Quantitative Analysis of Biomolecules
Biochemical analysis involves the characterization of biomolecules within a sample using appropriate laboratory techniques. There are two principal approaches:
1. Qualitative analysis – where a sample is analyzed to determine whether a biomolecule is present or absent. As an example, a blood sample might be analyzed for a specific antibody or a bacterial cell might be probed for a nucleic acid sequence.
2. Quantitative analysis – where the quantity of a particular biomolecule in a sample is determined, either as an amount (e.g. as g, or mol) or in terms of a concentration in the sample (e.g. as g/l, or mol/l). For example, a blood sample might be analyzed to determine its pH (-log10 [H+]), alcohol concentration in mg/mL, or glucose concentration in mmol/l.
Your choice of approach will be determined by the purpose of the investigation and by the level of accuracy required. Major types of biomolecules that are assayed include amino acids, peptides, proteins, carbohydrates, sugars, and nucleic acids.
Using a Standard Curve in Quantitative Analysis
There are many instances in biological research where it is necessary to accurately measure the quantity of an analyte (test substance) in a sample. The analyte is detected and quantified by measuring a ‘signal’ (measured response). In some instances, you can measure a signal due to an inherent property of the analyte, e.g. the absorption of UV light by nucleic acids, whereas in other cases you will need to react it with another substance to measure a signal. The signal is usually color, fluorescence, or radioactivity, which can be easily detected using the appropriate procedure and equipment.
In order to quantify the amount or concentration of an analyte in a sample, a standard curve (calibration curve) is usually generated. The standard curve is a graph that established the relationship between signal intensity and amount or concentration of
Quantitative Analysis of Biomolecules
Biochemical analysis involves the characterization of biomolecules within a sample using appropriate laboratory techniques. There are two principal approaches:
1. Qualitative analysis – where a sample is analyzed to determine whether a biomolecule is present or absent. As an example, a blood sample might be analyzed for a specific antibody or a bacterial cell might be probed for a nucleic acid sequence.
2. Quantitative analysis – where the quantity of a particular biomolecule in a sample is determined, either as an amount (e.g. as g, or mol) or in terms of a concentration in the sample (e.g. as g/l, or mol/l). For example, a blood sample might be analyzed to determine its pH (-log10 [H+]), alcohol concentration in mg/mL, or glucose concentration in mmol/l.
Your choice of approach will be determined by the purpose of the investigation and by the level of accuracy required. Major types of biomolecules that are assayed include amino acids, peptides, proteins, carbohydrates, sugars, and nucleic acids.
Using a Standard Curve in Quantitative Analysis
There are many instances in biological research where it is necessary to accurately measure the quantity of an analyte (test substance) in a sample. The analyte is detected and quantified by measuring a ‘signal’ (measured response). In some instances, you can measure a signal due to an inherent property of the analyte, e.g. the absorption of UV light by nucleic acids, whereas in other cases you will need to react it with another substance to measure a signal. The signal is usually color, fluorescence, or radioactivity, which can be easily detected using the appropriate procedure and equipment.
In order to quantify the amount or concentration of an analyte in a sample, a standard curve (calibration curve) is usually generated. The standard curve is a graph that established the relationship between signal intensity and amount or concentration of