Cell Tonicity Quiz

A semi-permeable membrane separates two solutions. Solution A has a 10% the concentration of sugar and solution B has a 40% sugar concentration. What direction would you expect the water to move, from A to B or B to A? What is this process called?

A to B. A has more water than B, so it's A to B. This is called Osmosis.

What does phospholipid contain?

Tail and head

hydrophilic means

loves water

hydrophobic means

scared to water

Tails or heads, which is hydrophyllic to water

Heads

Is the tail in phospholipid hydrophobic or hydrophilic

hydrophobic

In studying human physiology, why is it important to understand osmosis?

Osmosis helps us understand how cell transportation works and answers key questions related to water content in the body. For example, why do we salt meat (answer: meat has more water, so it goes out through osmosis, preventing bacteria from growing).

Hypertonic means

water is going out from the cells

Hypotonic means

Water is going into the cells

Isotonic

Water is balanced

The receptors for thirst are located in a part of the brain called the hypothalamus. These receptors, called osmoreceptors, are stimulated by an increase in blood osmolality. Imagine a man who has just landed on a desert island. Trace the course of events leading to his sensation of thirst. Can he satisfy his thirst by drinking seawater? Explain your answer.

The desert area has little water while the person has high water. So water will go out from his body in the form of sweat. Now the water goes out; the body needs water to maintain temperature and do other stuff. So, it sends him thirst signals. Salt water will not help because salt water has little water in them too. So, if he drinks that salt water, the water from his body will go into the salt water (because, again, salt water has low water content since most of it is salt), and thus, he will lose soo much more water from his body. That's why never drink salt water when you are thirsty.

Before the invention of refrigerators, pioneers preserved meat by salting it. Explain how meat can be preserved by this procedure.

Let's call meat as A and salt we add as B. Here A has water in it while B doesn't cuz B is just pure salt. Now, remember water flows from high to low. A has water and B doesn't, so water from A will go to B. This way, the water from A would completely drain off. If there is no water in the meat, then the bacteria wouldn't survive. Thus if bacteria can't live there, the food can be preserved for a long time.

Research and describe two diseases/disorders related to electrolyte imbalance, including information about hypertonic and hypotonic conditions of nitrogen, calcium, sodium, and potassium.

Diarrhea and cell bursting.

Diffusion means

Movement from high to low. Doesn’t need energy. Think of rolling down a hill as an example

Osmosis

A more advanced type of diffusion. Needs a cell membrane. Think of your water filter at your house.

What is diffusion/osmosis between intracellular and extracellular fluids dependent upon?

Salt and water concentration.

How can osmosis cause crenation of red blood cells? Hemolysis?

If there is more water outside than the cells, then the water will start gushing into the cell (hypotonic) this will make the cells burst aka hemolysis.

How much water composes the average human body?

Average human body is 55% water.

What organ contains the most water?

Lungs (90% water)

Give two examples of why water is important to the human body?

Dehydration Synthesis (adding two molecules by releasing water) and Osmosis

Explain how prolonged diarrhea can result in a water imbalance within the body.

With diarrhea, you release more and more water out of the body. So, that will lose your overall water composition in the body, thus can result in an imbalance.

Why is it worse for an individual to “breathe” in salt water rather than freshwater?

Saltwater will take water out of you, and freshwater will add water to you. Our cells are a bit resistant to bursting, so it's okay to have a little bit of excess water; our cells can store it without bursting. Saltwater takes water out of our body (again cuz they have a low concentration of water), and losing water means we can't do dehydration synthesis and many other body functions, so our body function will stop. Thus it's bad to lose water via salt water than to have more water via fresh water.