biology 3.3

t/f Active transport needs energy

true

t/f Carrier proteins change shape when they transport substances

true

t/f Channel proteins and carrier proteins are both transport proteins

true

t/f Diffusion does not require any help from other molecules

true

t/f Endocytosis and exocytosis are types of vesicle transport

true

t/f Osmosis is the diffusion of water

true

Energy for active transport is supplied by molecules of ____________.

ATP

Explain why passive transport does not require energy

The substances are moving from high concentration to low concentration, so not a lot of energy is needed.

How is water transported across the membrane?

Water is transported by osmosis.

____________ is the type of vesicle transport that moves a substance into the cell.

endocytosis

Explain how cell transport helps an organism maintain homeostasis.

Cell transport keeps conditions within normal ranges inside all of an organism's cells.

What are the two types of transport proteins? Describe how they function

Channel proteins and carrier proteins. Channel proteins work by allowing water molecules and other small molecules through the membrane. Carrier proteins bind with specific molecules and change shape.

What is a main difference between diffusion and facilitated diffusion?

Diffusion doesn't require help but facilitated diffusion requires help for molecules to diffuse.

Assume a molecule must cross the plasma membrane into a cell. The molecule is a very large protein. How will it be transported into the cell? Explain your answer.

It will be moved into the cell by facilitated diffusion, because larger molecules cannot easily cross the cell membrane and need help in doing so.

What is osmosis? What type of transport is it?

Osmosis is the diffusion of water molecules across a membrane. It is passive transport.

Compare and contrast simple diffusion and facilitated diffusion. For each type of diffusion, give an example of a molecule that is transported that way.

Simple diffusion is the diffusion of molecules that don't require help and facilitated diffusion is the diffusion of molecules that do require help. Both of these processes involve diffusing molecules. - An example of a simple diffusion molecule is oxygen, and an example of a facilitated diffusion molecule is glucose.

Describe how simple diffusion proceeds. What kind of molecules can move across the membrane by simple diffusion?

Simple diffusion works by a substance moving across the membrane without help from other molecules. Small, hydrophobic molecules move by simple diffusion.

What is the sodium-potassium pump?

The sodium-potassium pump is a type of active transport in which sodium ions are pumped out of the cell and potassium ions are pumped into the cell with the help of a carrier protein and energy from ATP. Sodium ions get pumped out of the cell and potassium ions get pumped into the cell.

Name two types of vesicle transport. Which type moves substances out of the cell?

The two types are exocytosis and endocytosis. Exocytosis moves substances out of the cell.

Describe the roles of transport proteins in cell transport.

Transport proteins help with diffusion of cells across the membrane, called facilitated diffusion.

A ____________ protein changes shape as it carries ions or molecules across the membrane.

carrier

which two transport proteins are involved in facilitated diffusion?

carrier proteins and channel proteins

____________ refers to the number of particles of a substance per unit of volume.

concentration

t/f Endocytosis removes large molecules from the cell

false

t/f Facilitated diffusion does not require any help from other molecules

false

t/f In diffusion, substances move from an area of lower concentration to an area of higher concentration

false

t/f Ions can easily flow through a carrier protein

false

t/f Passive transport needs energy

false

t/f The sodium-potassium pump is a type of channel protein

false

By moving substances into and out of cells, ____________ , the process of keeping stable conditions inside a cell, is maintained.

homeostasis

what types of molecules can go through facilitated diffusion?

hydrophilic molecules, charged ions, and relatively large molecules

During active transport, a substance is moving from an area of ____________ concentration to an area of ____________ concentration.

lower ; higher

Moving molecules in and out of the cell is an important role of the ____________.

membrane

____________ is the diffusion of water.

osmosis

____________ transport is movement across the plasma membrane that does not require an input of energy.

passive

in the sodium-potassium pump, which molecules are pumped into the cell and which molecules are pumped out of the cell?

potassium = in ; sodium = out

The sodium-potassium ____________ is involved in the active-transport of ions.

pump

what are the types of passive transport?

simple diffusion, facilitated diffusion, and osmosis

what types of molecules can go through simple diffusion?

small, hydrophobic molecules such as molecules of oxygen and carbon dioxide

what is an example of active transport?

sodium-potassium pump

Facilitated diffusion needs the help of ____________ proteins.

transport/carrier

t/f Channel proteins form small "holes" in the plasma membrane

true

t/f The plasma membrane controls what enters and leaves the cell

true

t/f Transport of substances across the cell membrane helps maintain homeostasis by keeping the cell's conditions within normal ranges

true

Exocytosis is the type of ____________ transport that moves a substance out of the cell.

vesicle