AP BIOLOGY

Water Potential Experiments

CARROT & GUMMY BEAR

During these experiments, my lab partner and I compared how different foods absorbed amounts of solute. We also observed how carrots absorbed a sugar solution and how gummy bears absorbed a salt solution. We began by weighing the foods in grams and placing each in a 100mL cup of water as our control. We put our independent variable foods in solutions of both water and salt for their selective experiment. After 48 hours, we observed how the foods reacted to their time in these solutions. We both weighed the foods and visually observed. With carrots, they became more buoyant. We also noticed that the more sugar per solution, the darker the carrots became. With gummy bears, we noticed that the gummy bears with salt became more opaque compared to the ones put solely in water, which became more translucent.

Egg

During the egg portion of the experiment, we observed both osmosis and exosmosis. We began by weighing our eggs and placing them in vinegar for 48 hours. To observe the effects, we weighed our egg and assessed its impact. We also removed the shells by rinsing them gently with water. We noticed that the egg had become swollen after soaking in a hypotonic solution. Next, we soaked the (now shell-less) egg in a hypertonic solution, corn syrup. After another 48 hours, we weighed the (now shriveled) egg. We noticed that it had lost its buoyancy.

Cell Membrane methods of transport

Active Transport

This part of the diagram shows active transport, as the movement of molecules across a cell membrane, often against their concentration gradient, which requires cellular energy, typically in the form of ATP. In the diagram, we included labels of the polar and nonpolar tails of the phospholipids. We also included the saturated and unsaturated tails.

Facillitated Diffusion

This section of the diagram displays facilitated diffusion, as channel proteins move molecules across a cell membrane down their concentration gradient with the help of transport proteins, such as channel or carrier proteins. We included cholesterol moving from areas of high concentration to low concentration.

Simple Diffusion

This section of the diagram displays simple diffusion, where molecules exhibited move down the concentration gradient. This means they move from areas of high concentration to areas of low concentration. One of the most common molecules present within simple diffusion is oxygen. In the diagram, it moves between the phospholipids in the intercellular space to reach the cell.

Macromolecules Posters

Within these posters, we researched the different properties of lipids, proteins, nucleic acids, and carbohydrates. Afterwards, the class shared and quizzed each other on these properties.

Macromolecules Lab

Within this lab, we had to investigate how different substances reacted to compounds joining them.

PROPERTIES OF WATER POSTER

Within these posters, we researched the different properties of water. This includes cohesion and adhesion, surface tension, high specific heat and vaporization, as well as solvency

PROPERTIES OF WATER LAB

Within this lab, we examined the properties of water. We started with celery soaked in food coloring and water, where the celery changed colors after 48 hours. This taught us adhesion and cohesion. We also studied surface tension by investigating the hydrogen bonds in water and its density.

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