Active and Passive Transport

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?

the relative inelasticity and strength of the plant cell wall

A 0.9% NaCl solution is isotonic to red blood cells. Which of these describes the results if red blood cells are placed into a 9% solution of NaCl.

They will shrink

Facilitated diffusion across a biological membrane requires [blank] and moves a substance [blank] its concentration gradient

transport proteins/down

The molecules responsible for membrane transport are

proteins

Know the steps of the Sodium potassium pump.

1) 3 sodium bind to protein. ATP binds to protein at the same time and attaches a phosphate (facing inside the cell) 2) The proteins change shape because of the ATP. 3 sodium are pushed outside of the cell (facing the outside of the cell now) 3) 2 potassium bind to the protein. The phosphate from the ATP is released. Protein changes shape. (facing back inside again) 4) Releases potassium inside of the cell. Process is repeated

Which of the following statements regarding active transport is false?

Active transport is driven by the concentration gradient

Inside one osmosis bag, A, is a 50% glucose solution and inside bag B is a 20% glucose solution. Both bags are put in beakers containing 100% water.

Both bags will gain weight

Which of the following statements regarding diffusion is false?

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated

Compare and contrast hypertonic, hypotonic, and isotonic solutions (be able to identify a solution as hyper, hypo, or iso by looking at a picture)

Hypertonic - higher solute concentration, cell will shrink Hypotonic - low solute concentration, cell will grow Isotonic - same solute concentration, water will go in and out at equal rates All - osmosis solutions

Why is getting the wrong blood type bad? Why must blood be isotonic?

Immune system will attack it due to marker proteins water will exit your cells

What will happen to a typical animal cell if placed in a solution containing 40% solute? Is it in a hypertonic, hypotonic, or isotonic solution. Explain.

It is hypertonic because water will exit the cell and the cell will shrink.

What will happen to a typical animal cell if placed in a solution containing 50% solute? Is it in a hypertonic, hypotonic, or isotonic solution. Explain.

It is hypertonic because water will exit the cell and the cell will shrink.

What will happen to a typical animal cell if placed in a solution containing 30% solute? Is it in a hypertonic, hypotonic, or isotonic solution. Explain.

It is in an isotonic solution where water will go in and out of the cell at equal rates and the cell will not change

White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs). When looking at a sample of blood for WBCs, what could you do to reduce interference from RBCs?

Mix the blood in a hypotonic solution, which will cause the RBCs to lyse

Which of the following substances would have the most trouble crossing a biologival membrane by diffusing through the lipid bilayer?

Na+

Compare and contrast active and passive transport.

Passive - no energy required, with concentration gradient (high to low) Active - ATP energy required, against concentration gradient (low to high)

What is the difference between integral and peripheral proteins?

Peripheral - only in inner or outer surface of phospholipid Integral - embedded in whole bilayer

Know the symptoms, treatments, the associated gene, and life span of someone with Cystic Fibrosis

Symptoms - diabetes, osteoperosis, reproductive problems, pancreas problems, trouble absorbing nutrients Treatments - special diets, physical chest therapy, chest slapping, antibiotic therapy, vibrating vest Associated Gene - CFTR Average Life Span - about 30-50 years

Which of the following statements is true among all types of passive diffusion?

The concentration gradient is the driving force

Which of the following is a typical feature of an ATP-driven active transport mechanism?

The solute moves against the concentration gradient

In the lab, you use a special balloon that is permeable to water, but not sucrose, to make an "artificial cell". The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?

Water will leave the balloon

The U-shaped tube in the figure below is divided by a membrane that is impermeable to starch but permeable to water. Which of the following will occur?

Water will move from the left to the right

Two beakers are connected by a tube partitioned by a membrane permeable to water but not to protein. Which one of the following statements best describes what will happen to this system?

Water will move in both directions, but the net flow will be from A to B

What type of transport is the sodium-potassium pump?

active

Which of the following processes can move a solute against its concentration gradient?

active transport

Which of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings?

active transport

What are some different names for the plasma membrane?

cell membrane, phospholipid bilayer, lipid bilayer, fluid mosaic

The solutions in the 4 artificial cells diagrammed below are separated from each other by stationary, differentially permeable membranes. The membranes are permeable only to the water. As the experiment progresses, which of the following is true about the amount of sucrose in the cells. It

does not change in any cell

Compare and contrast endocytosis and exocytosis

endocytosis - transport materials into cell exocytosis - transport materials out of cell both - forms of active transport

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will

exhibit a net movement to the side with lower water concentration

Describe the following: exocytosis, endocytosis, receptor-mediated endocytosis, pinocytosis, phagocytosis

exocytosis - transport materials out of cell endocytosis - brings materials into the cell Receptor-mediated endocytosis - receptor proteins in plasma membrane bind and move to coated pit pinocytosis - bring in liquids to cell phagocytosis - bring in solids to cell

Why is the membrane like a fluid mosaic?

fluid - very flexible mosaic - proteins scattered throughout the membrane

What is the function of microvilli?

helps to increase the surface area of the cell

In the lab, you use a special balloon that is permeable to water, but not sucrose, to make an "artificial cell". The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the balloon is [blank] relative to the solution in the beaker.

hypotonic

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment

is hypotonic to the protozoan

A plant cell in a hypotonic solution

is turgid

A cell that neither gains nor loses water when it is immersed in a solution is

isotonic to its environment

In a hypotonic solution, an animal cell will

lyse/burst

A red blood cell has a salt concentration of 0.9%. What will happen if it is placed into a 0.8% salt solution? The red blood cell will

maintain its shape, i.e. nothing will happen

What does selectively permeable mean?

only allows certain materials to pass through (small and nonpolar materials tend to pass easily)

What are some examples of passive transport?

osmosis, diffusion, facilitated diffusion

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of

passive transport

Oxygen crosses a plasma membrane by

passive transport

What are some examples of active transport?

sodium potassium pump, endocytosis, exocytosis

Wallaway is a new general herbicide for aquatic plants. It is effective against freshwater but not saltwater plants. It works by breaking down the cell walls of the plants. The freshwater plants die because their cells

swell and burst

Osmosis can be defined as

the diffusion of water

What is osmosis and how do living things deal with osmotic pressure?

the diffusion of water across a selectively permeable membrane kidneys and cell wall

You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result,

you dehydrate yourself