Determining the Water Potential of a Plant Cell

Flashcards based on the lecture notes covering concepts related to the water potential of plant cells and methods to investigate osmosis.

What does a dilution series help to investigate in biology?

A dilution series helps to investigate how the concentration of a solute affects phenomena like the movement of water.

What two methods can be used to make a dilution series?

Serial dilutions and proportional dilutions.

What are the four methods by which substances can cross cell membranes?

Passive diffusion, facilitated diffusion, osmosis, and active transport.

What is water potential a measure of?

Water potential is a measure of the pressure that water exerts on its surroundings.

What is the water potential of pure water?

The water potential of pure water is 0 kPa.

How does the presence of solutes affect water potential?

Adding solutes lowers the water potential.

What happens to water movement in relation to the concentration gradient?

Water moves by osmosis to balance out the concentration gradient.

Why are ionic compounds more effective than non-polar molecules in terms of osmosis?

Ionic compounds dissociate into more than one ion, affecting osmosis more than non-polar molecules.

What is a common method to measure osmosis in plant cells?

Using potato cubes to measure osmosis in different sucrose solutions.

What is important to ensure while conducting osmosis experiments with potato cubes?

Potato cubes must be identical in shape to avoid variability in surface area to volume ratio.

What must be done before weighing potato cubes to ensure accuracy?

Weigh potatoes immediately before and after placing within sucrose solution.

How should data from the osmosis experiment be recorded?

Data should be recorded in tables with clear titles, independent variable on the left, dependent variable on the right, and units only in headings.

What does the % change in mass indicate in an osmosis experiment?

The % change in mass indicates the net direction of water movement via osmosis.

What is an estimated water potential of potato cells based on sucrose solution?

The water potential of potato cells is estimated to be around -700 kPa.

What are some potential sources of error in the osmosis experiment?

Anomalous results may stem from inaccuracies in weighing, differences in solution clinging, or improper sucrose solution preparation.

What can be done to improve the accuracy of the osmosis experiment?

Use cutters for consistent potato shapes, more interval sucrose concentrations, and replicate experiments for reliable conclusions.