Question

In a study of schizophrenia, researchers measured the activity of the enzyme monoamine oxidase (MAO) in the blood platelets of 18 patients. The results (expressed as nmoles benzylaldehyde product per 108 platelets) were as follows: 13 \(\begin{array}{llllrr}6.8 & 8.4 & 8.7 & 11.9 & 14.2 & 18.8 \\ 9.9 & 4.1 & 9.7 & 12.7 & 5.2 & 7.8 \\ 7.8 & 7.4 & 7.3 & 10.6 & 14.5 & 10.7\end{array}\) Construct a dotplot of the data.

Short answer

The dotplot is a graph where each MAO activity level is marked on a horizontal scale, with dots above the scale indicating the number of times each value occurs.

Step-by-step solution

Arrange the Data in Ascending Order

Before plotting the data on a dotplot, arrange the values in ascending order to make it easier to see how many times each value occurs. This will simplify plotting the dots on the graph.

Create a Scale for the Dotplot

Set up a horizontal scale on your dotplot that includes the range of MAO activity levels observed in the study, from the smallest to the largest value.

Plot the Data Points

Above each value on the horizontal scale, place a dot for each occurrence of that value in the data set. If a value occurs more than once, stack the dots vertically.

Key concepts

Data Visualization

Data visualization is an essential aspect of understanding and communicating complex information effectively. It involves converting data into a graphical format, such as charts, graphs, and plots, making it easier to see patterns, trends, and outliers. For example, a dotplot is a type of data visualization that can display the distribution of a data set in a simple, visually appealing way.

A dotplot consists of a horizontal axis representing the range of data and dots that represent each occurrence of a data point. In the case of measuring enzyme activity, like monoamine oxidase (MAO) in a group of patients, a dotplot can clearly show how enzyme activity levels are distributed among the patients and whether there are any clusters or gaps in the data.

To create a more effective dotplot, it is imperative to ensure that the axis is appropriately scaled and that each data point is accurately represented. A well-constructed dotplot can reveal the concentration of data points and variation within the data set at a glance, which is invaluable for preliminary analysis.

Statistical Analysis

Statistical analysis involves collecting, examining, interpreting, and presenting data to uncover underlying patterns and trends. In health-related research, such as studying enzyme activity for patients with schizophrenia, statistical analysis is crucial to draw meaningful conclusions.

After visualizing data using a dotplot, it is important to apply statistical methods to analyze the data further. This may include calculating measures of central tendency (like mean and median), dispersion (like range and standard deviation), and performing hypothesis testing to determine if observed patterns in the data occurred by chance or signify something more substantial.

With the MAO enzyme activity levels organized into a dotplot, statistical analysis can help researchers understand the typical activity level, the variability among patients, and identify any outliers that might be of particular clinical interest. Such in-depth analysis can provide insights that drive further research or inform treatment approaches.

Enzyme Activity Measurement

Enzyme activity measurement is a critical component in biochemical and medical research. Enzymes, being catalysts for biochemical reactions, have activities that can be quantitatively measured to assess various physiological or pathological conditions.

Enzyme activity is commonly expressed in units that reflect the amount of substrate converted to product over time under specific conditions. In the above exercise, the activity of monoamine oxidase (MAO) is measured in nanomoles of benzylaldehyde product per 10^8 platelets, which provides a specific quantitation of the enzyme's activity in the blood.

Accurate measurement of enzyme activity is vital as it can indicate the presence of a disease, its progression, or the efficacy of a treatment. By comparing enzyme activity levels across different study groups or with established normal ranges, researchers can draw conclusions about the role of the enzyme in the condition of interest. The careful organization and analysis of this data, often starting with clear visualization techniques such as dotplots, are foundational to advancing our understanding of complex biological processes.