Active TransportBothPassive Transport Compare and contrast active and passive transport on a Venn diagram. Biology Journal 9/17/2015

Active TransportBothPassive Transport Against diffusion Movement of molecules With diffusion Low to high concentration Molecules pass through cell membrane High to low concentration Requires energy Are ways that cells regulate what enters/leaves No energy required Always involves a protein channel Sometimes involves a protein channel Compare and contrast active and passive transport on a Venn diagram.

1.3 Membrane Structure 1.4 Membrane Transport Review Questions

What is diffusion? Diffusion is the automatic movement of molecules from a high concentration to a low concentration.

Make a drawing of a phospholipid. Label the phosphate, the lipids, the hydrophobic part and the hydrophilic part. Phosphate Phosphate has a charge, like water. This is hydrophilic (attracted to H 2 O) Lipids Also known as “fats” These 2 tails are hydrophobic (repels H 2 O)

A. What process is happing in step 2? B. What process is happening in step 6? Bacteria Phagocytosis Exocytosis

What is equilibrium? Equilibrium is when all concentration in an area are equal, so diffusion is no causing a net change in concentrations.

What is osmosis?

Osmosis is the diffusion of water. H 2 O goes from a high concentration to a low concentration.

Draw a 2-d picture of the fluid mosaic model. Draw and label phospholipids correctly oriented, a transport protein, a glycoprotein, and label the regions as hydrophobic or hydrophilic.

(aka transport protein, aka protein channel)

1.What is the purpose of cholesterol in a cell membrane? 2.Would a muscle cell have a high or low amount of cholesterol? Why? 3.Would a plant cell have a high or low amount of cholesterol? Why?

1.Cholesterol makes cell membranes more rigid and inflexible. 2.Muscle cells are low in cholesterol so that they can easily move! 3.Plant cells don’t move, but they have no cholesterol. They don’t need it! They have a cell wall that prevents them from moving. Bruce Lee’s 1 inch punch. He strikes another martial artist from a distance of only 1 inch away.

What kind of transport is going on in these 3 pictures? (active or passive?)1 2 3

Shown are 3 plant cells. Which one would show the result of being in a solution with the highest concentration of water? Explain your answer. Cell A! The high concentration of water in the solution diffuses to the lower concentration inside of the cell (remember, the cytoplasm of cells isn’t pure water), causing it to swell. This process is osmosis. AB C

Some molecules on the cell membrane are called receptors. What is the function of these molecules? Receptors are kind of like the ID of a cell. They identify the cell, and allow it to communicate with other cells. For example, your receptors are the way that your immune system identifies cells, and eliminates cells that don’t belong.

Pictured is a membrane protein called the sodium- potassium pump. It uses active transport to move Na and K ions. What are 2 things in the picture that tell us that this is active transport? 1.The Na’s and K’s are going from low concentration to high concentration (against diffusion) 2.The picture shows “ATP” which is energy. Active transport takes up energy.

1.Diffusion requires energy. 2.All plants have cholesterol to keep their cell membranes rigid. 3.A cell consuming a large quantity of cells would be called endocytosis. 4.All active transport takes place through a protein channel. 5.Water is hydrophilic. 6.Phospholipids are both hydrophobic and hydrophilic. False Write out True or False… False True

If you set up this container like this, the liquid levels will change. On one side the liquid will rise, and on one side the liquid will fall. Which side will the liquid rise? Why? (Can’t pass through membrane) (Can pass through membrane) AB

Side A rises! This is because water moves from a high concentration on side B, to the low concentration on side A. This will continue until the concentrations are the same (equilibrium). Osmosis will continue until the concentrations are the same.

EndocytosisBothExocytosis Compare and contrast endocytosis and exocytosis on a Venn diagram. Think of at least 2 points for each area.

EndocytosisBothExocytosis Molecules enter cell Involve vesicles, which are made of phospholipids Molecules leave cell Cell membrane pinches in, creating vesicle Large amount of molecules transported Vesicle approaches cell membrane, and merges with it, releasing molecules Ex: cell taking in nutrients Golgi complex controls process Ex: Cell releasing hormones Requires energy