Solving Botany Questions: Adding Sugar to Raspberries & Potato/Beet Tissue

[disruptors]

Hey guys, I've been spending a 3 hrs trying to figure this one out...

1) Why does adding sugar to rasberries make them juicy? to rephrase I mean why would the entire raspberry/sugar concoction become more juicer as
a whole (why will there end up being juice in the bowl?)


It has to do with water movement, is it because since the salt is on the outside it moves from lower solute concentration to higher solute concentration on the outside? I just can't imagine it.

2) What does the calculated hydrostatic pressure value indicate about the turgor pressure of the intact potato and beet tissue?

This question is from my water potential lab assignment. My answer is:

The hydrostatic pressure of 2.44 Mpa for the potato (the value I got) indicates that the turgor pressure is positive and that the cells of the potato are well hydrated with a rigid cell wall. The negative hydrostatic pressure of -.0352 Mpa for the beet tissue indicates a negative turgor pressure and that the cells are not hydrated well with water, which causes flaccid cells.

I am not sure if what i put is answering the question?

Thanks a lot guys, I am stuck on these and been working at it for 4 hrs now, and its due tomm, just wanted to make sure I am on the right track. Thanks again!

 

[Moonbear]

For (1), you're somewhat on the right track, but it's not salt that moves. Where did you change the solute concentration, and what else would have to change to reach equilibrium again?

For (2), did you really mean to say cell wall for the potato? Otherwise, I think you're doing okay on that one (though, I can't speak for your teacher if they like more explanation or not).

 

[Blueshift5]

I can provide some insight and clarification on these questions. First, let's address the question about adding sugar to raspberries. When sugar is added to raspberries, it creates a hypertonic solution. This means that there is a higher concentration of solutes (sugar) outside of the cells compared to inside the cells. Water will naturally move from an area of lower solute concentration (inside the cells) to an area of higher solute concentration (outside the cells) in an effort to balance out the concentration. This process is called osmosis. As water moves out of the cells, the cells become dehydrated and shrink, causing the raspberries to become softer and juicier.

Now, onto the second question about hydrostatic pressure and turgor pressure. Hydrostatic pressure is the pressure exerted by a fluid (in this case, water) in a confined space. Turgor pressure, on the other hand, is the pressure exerted by the cell contents against the cell wall. In a healthy plant cell, turgor pressure is positive and helps maintain the rigidity of the cell wall. However, when there is a negative turgor pressure, it means that there is not enough water in the cells to exert pressure against the cell wall, causing the cells to become flaccid and wilted.

Based on your answers, it seems like you are on the right track. The hydrostatic pressure values you calculated for the intact potato and beet tissue indicate the turgor pressure of each tissue. The positive value for the potato suggests well-hydrated cells, while the negative value for the beet tissue suggests dehydrated cells. I hope this helps clarify things for you. Good luck with your assignment!