Question

Dialysis can seperate, which of the following in addition to the glucose from the human blood? (a) Sucrose (b) Fructose (c) Alcohol (d) Proteins

Short answer

Dialysis can separate small molecules like glucose from the blood, so in addition to glucose, sucrose (a), fructose (b), and alcohol (c) can also be separated, while proteins (d) cannot.

Step-by-step solution

Understand the Concept of Dialysis

The first step is to understand what dialysis is and how it works. Dialysis is a medical process that filters and purifies the blood using a machine. This is helpful for people whose kidneys are not capable of performing these functions naturally. The process separates small waste molecules and excess substances from the blood, which can then be removed from the body.

Identify the Molecules That Can Be Separated by Dialysis

In the context of dialysis, it is essential to know which types of substances can be separated from the blood. Generally, dialysis can separate small molecules like glucose and salts, while larger molecules such as proteins and cells are too large to pass through the dialysis membrane.

Apply the Principle to the Given Options

Using this knowledge, analyze the provided options to determine which substances can be separated by dialysis. Option (d) Proteins are typically too large to be filtered through dialysis membranes. Options (a) Sucrose, (b) Fructose, and (c) Alcohol are smaller molecules, similar in size to glucose, and can be separated from the blood through dialysis.

Key concepts

Kidney Function and Dialysis

The human kidney is a vital organ that maintains the body's internal equilibrium of water and minerals. It performs this function by filtering blood, removing waste products, reabsorbing necessary nutrients, and excreting urine.

However, when kidneys fail to function properly due to diseases or injury, harmful substances like urea and creatinine can build up in the blood, a condition known as uremia. This is where dialysis comes into play. Dialysis replicates the blood-cleansing functions of the kidneys. It removes waste products and extra fluids from the blood, effectively substituting for some of the kidney's essential roles.

To improve the exercise, students can benefit from understanding that there are two main types of dialysis: hemodialysis and peritoneal dialysis. Hemodialysis involves a machine and a special filter called a dialyzer, or artificial kidney, where the blood is cleaned outside the body. Peritoneal dialysis uses the lining of the abdomen to filter blood inside the body. Familiarity with these methods can help students contextualize the purpose and mechanisms of dialysis.

Separation of Molecules in Dialysis

Dialysis works on the principle of diffusion and osmosis through a semipermeable membrane. This membrane allows certain substances to pass through while blocking others.

To enhance comprehension, picture the dialysis membrane as a fine sieve that separates molecules based on their size and sometimes their electrical charge. Small waste molecules such as glucose, urea, fructose, alcohol, and salts pass through the membrane and are removed from the blood. These small particles move from an area of higher concentration (the blood) to an area of lower concentration (the dialysis solution), a process guided by the concentration gradients of the solutes.

In contrast, larger molecules such as proteins and blood cells are typically too big to pass through the microscopic pores of the dialysis membrane. It's essential for educators to explain that the success of this separation process is vital for the adequate removal of toxic substances while keeping the necessary larger molecules in the bloodstream.

Dialysis Membrane Selectivity

When discussing dialysis membrane selectivity, it's important to communicate that the membrane's permeability is selective and typically based on the size and sometimes the charge of molecules. This selectivity is critical in mimicking the selective filtration function of healthy kidneys.

Emphasizing the role of the membrane's pore size enhances student understanding. For instance, explaining that during dialysis, molecules like sucrose, fructose, and alcohol can pass through the membrane due to their relatively small size compared to proteins, which are generally retained because of their larger size.

To give students a concrete example: blood cells and proteins play crucial roles in the body - blood cells in oxygen transport and proteins in various bodily functions. Therefore, the dialysis membrane is designed to be selective enough to retain these important components in the bloodstream. Understanding this can help students appreciate the critical balance between removing harmful toxins and retaining essential elements in the blood during the dialysis process.