8.1 and 6.2 bio test

What is the solvent? -What is the universal solvent?

The part of a solution that does the dissolving; the part of a solution in which the solute is dissolved(water) -Water

What is a solute?

The part of a solution that is dissolved

What causes a cell to shrink?

Hypertonic solution

What causes a cell to swell?

Hypotonic solution

What causes osmosis?

Hypotonic solution and hypertonic solution

Explain how hypotonic and hypertonic solutions can make a plant rigid and form or make it wilt.

Hypotonic will make that plant rigid and firm and hypertonic will shrink the plant.

How does amoeba get its food?

It moves its psuedopodia around the food particle

Osmosis

The diffusion of water

What is osmotic pressure?

The force exerted by water outside the cell membrane in plant cells and on both sides of the cell membrane in animal cells

What happens when a plant cell is placed in a hypotonic solution?

The greatest concentration of water is outside the cell. Therefore, water enters the cell and fills the central vacuole, causing the contents of the plant cell to press against the cell wall. The plant cell swells and stiffens as turgor pressure increases.

The cell membrane contains ___ molecules that are embedded in the lipid bilayer

lipid

a solution is a ___ of two or more substances

mixture

define diffusion

movement of particles from one area of higher concentration to an area of lower concentration

because cells are hypertonic in relation to fresh water _________ produces a net movement of water into the cell. If that happens, the cell will become ____ and can even burst

osmotic pressure ; swollen

if a substance is able to diffuse across a membrane, the membrane is said to be ...

premeable to it

what is the main function of the cell wall?

provides support and protection

diffusion depends on ___ particle movements, therefore it (does or doesn't) require energy?

random ; doesn't

one of the most important functions of the cell membrane is to ___ the movement of dissolved ___ from the liquid on one side of the membrane to the liquid on the other

regulate; molecules

Name two functions of the cell membrane

seperates the cell from its surroundings and regulates traffic of molecules into and out of the cell

in plant and bacteria cells, what keeps them from bursting due to osmotic pressure?

the cell wall

When does osmosis stop?

1. when pressure on both sides of the cell membrane is equal 2. when cells are placed in an isotonic solution

What is the percentage of water molecules in distilled water?

100%

Facilitated diffusion

A form of passive transport that uses transport proteins

Active transport moves molecules (with or against) the concentration gradient ?

Against

When a cell is in a hypertonic solution, how will water molecules move?

Alot of water going out but little coming in

What is an isotonic solution?

The concentrations of dissolved particles(solute) are the same both inside and outside the cell

What factor controls the direction water molecules move during osmosis?

Concentration

Changes in protein shape seem to play an important role in the ____ process?

Endocytosis

Active transport requires?

Energy

Cells release large amounts of material in a process called?

Exocytosis

Which of the following is NOT an example of active transport?

Facilitated diffuison

Energy

Is used during active transport but not passive transport

In which type of solution is a cell in homeostasis (balance)?

Isotonic

What doesn't change the shape of a cell?

Isotonic solution

Isotonic, hypertonic, and hypotonic refer the effects of ___ on a cell.

Osmosis (movement/diffusion of water)

Passive Transport

Particle movement from an area of higher concentration to an area of lower concentration

Active transport

Particle movement from an area of lower concentration to an area of higher concentration

What are two types of endocytosis?

Pinocytosis and phagocytosis

Exocytosis

Process by which a cell expels wastes from a vacuole

Endocytosis

Process by which a cell takes in material by forming a vacuole around it

When given the percent concentration of solute, how do you calculate the percent concentration of solvent (water)?

Subtract the percent concentration of solute from 100%. The difference is the percent concentration of solvent (water).

What is a hypertonic solution?

The concentration of dissolved particles is higher outside the cell than inside

What is a hypotonic solution?

The concentration of dissolved particles is lower outside the cell than inside

What is turgor pressure?

The pressure exerted by the contents of a plant cell against the cell wall when water enters the central vacuole and surrounding cytoplasm (occurs when a plant cell is placed in a hypotonic solution)

What is concentration?

The ratio of solute to solvent

What causes a solution to be hypertonic?

There is more solute in the solution surrounding a cell than inside, resulting in a greater amount of water (solvent) inside the cell. The more solute, the less solvent (i.e. water).

What causes a solution to be hypotonic?

There is more solute inside the cell than in the solution surrounding the cell. As a result, there is more water molecules (solvent) surrounding the cell than water molecules inside the cell.

When a cell is in a isotonic solution, how will water molecules move?

They will move at equal rates

Carrier protein

Transport protein that changes shape when a particle binds with it

Channel Protein

Transport protein that provides a tubelike opening in the plasma membrane through which particles can diffuse

When a plant cell is placed in a hypertonic solution, what occurs?

Water inside the cell (highest concentration) moves out of the cell (lowest concentration), causing the plant cell to shrink and the plant to wilt. The plant wilts because there is a loss of turgor pressure.

When a cell is in a hypotonic solution, how will water molecules move?

Water will move inside the cell

Why do scientists call the membrane a "mosaic"?

because its made up of small pieces put together as one

what are plant cell walls composed of ?

cellulose

cell membranes have ___ that make it easy for certain molecules to cross the membrane

channels

when the particles are the same throughout, the system has reached ?

equilibruim

when proteins help molecules move across the membrane, it is called ____

facilitated diffusion

What 3 tyoes of organisms have cell walls?

fungi, plants and bacteria