AP Bio 2.8 Flashcards
What is osmosis?
Osmosis is the movement of water through a selectrively permeable membrane
What is osmolarity?
It’s the total solute concentration in a solution
What does tonicity affect?
The physiology of the cell
What is tonicity?
It’s the measurement of relative concentrations between two solutions
(in our case, inside and outside of the cell)
What is hypertonic?
There is more solute than solvent
What is isotonic?
Both concentrationsare the same
What is hypotonic?
There is less solute and more solvent
Which direction does water move to in osmosis?
From low to high concentrations
What is the relationship between water conc. and solute conc.?
An inverse relationship
What does osmoregularition do?
It maintains the balance of water concentration and water potential/solute composition.
What takes place when there is less solute inside of a plant cell than in its environment? (Environmental hypertonicity)
Plasmolysis, or the movement of water from the cell towards the outside environment occurs.
Bad
What happens when both the plant cell and environments concentrations are isotonic?
Water moves into and out of the cell at equal rates (no net movement) resulting in a flaccid condition for the cell.
Not good
What takes place when there is more solute inside of a plant cell than in its environment? (Environmental hypotonicity)
The movement of water from the environment towards the cell occurs, deeming it turgid.
Perfect
What is turgor pressure?
It is a pressure on the cell walls that occurs as a result of water moving into the cell and the vacuoles, which causes the cell to expand (causing it to be turgid).
What is turgidity?
It’s the optimum state for plant cells
What happens to an animal cell if there is less cellular solute than water?
Water will diffuse out, causing the cell to shrivel
Bad
What happens if the inside and outside of a cell are isotonic?
Water travels in and out of the cell at equal rates (dynamic equilibrium)
Perfect
What are the components of a successful graph?
- A title
- Labelled axes with units (X axis -> independent variable, Y axis dependent variable)
3 Scaling (must exhibit uniform intervals, must be large enough to analyze data, and must use scale numbers on grid lines) - Identifiable lines or bars (add a legend or label each line or bar)
- Trend line (it’s a line of best fit that shows the general pattern or overall direction of the data)
What’s a dependent variable?
Effect
What’s an independent variable ?
Cause
What are the different types of graphs?
- Line graphs
- X Y graph (scatter plot)
- Histogram
- Bar graph
- Box and whisker plots
- Dual Y graph
What are line graphs?
They are graphs that:
1. Reveal trends or progress over a changed variable for multiple groups or treatments
2. Track changes over time, concentrations, etc.
What’s an X Y graph?
It’s a graph used to determine relationships in different things, and their relationships may or may not be linear
What’s a histogram?
It’s a graph that shows a set of data distrubuted across evenly spaced or equal intervals, and it can help explore the relationships between two or more variables
What’s a bar graph?
It’s a graph that helps compare multiple groups or treatments to one another
What’s a box and whisker’s plot?
It’s a graph that helps show the variability of a sample, and that helps compare distributions in relation to the mean
What’s a dual Y graph?
It’s a graph that illustrates the relationship between 2 dependent variables
What does water potential measure?
It measures the waters tendency to move by osmosis
Water potential = …
Pressure potential + Solute potential
The unit of water potential is called bars
Water moves…
From an area of high water potential to low water potential
The value of water potential can be…
positive, negative, or zero
The more negative the water potential is…
The more likely that water would move into that area
if the water potential in a cell is -3 bars, and the water potential outside of a cell is -6 bars, in which direction will water flow?
Towards the outside of the cell
What is the water potential of pure water?
0 bars
Increasing the amount of solute in water will cause…
An increase in solute potential, and a decrease in water potential
Increasing water potential will cause…
An increase in pressure potential
And vice versa
In the formula for solute potential, -iCRT, what do the variables signiify?
i = ionization constart
C = no. of moles
R = pressure constant, 0.0831
T = temperature in Kelvin (C + 273)
What does pressure potential equal when the system is open?
0
