Cell Transport

Cell Transport Notes

Instructions:

Use this presentation to take notes on the different types of cell transport and how it helps the cell maintain function.

Cell Membrane

Cell Membranes surround ALL cells!

Controls what molecules enter and leave the cell

-  food & oxygen molecules must enter the cell

-  waste products need to be released

SEMIPERMEABLE – it allows some things through but not others

Multiple Choice

The cell membrane is selectively permeable, which means...

• All materials can enter and leave the cell
• Certain things can enter while others cannot
• The cell manually sorts through all materials
• Only certain cells can interact with the cell.

Phospholipid bilayer

Polar heads “love” water (hydrophilic)
Nonpolar tails “fear” water (hydrophobic)

Multiple Choice

Which type of biological macromolecule is the main component of the plasma membrane?

• carbohydrate

• lipid

• protein

• nucleic acid

Multiple Choice

Which part of the phospholipid is hydrophobic?

• The head

• The tails

• Only one tail

• The heart

Fluid Mosaic Model

Describes the various molecules found in the cell membrane

Example:

-Proteins: forms channels and pumps to move materials across membranes

- Carbohydrates: act like identification cards so cells can identify one another

Multiple Choice

What forms the channels and pumps in the phospholipid bilayer?

• carbohydrates
• proteins
• hydrophilic heads 
• lipids

Multiple Choice

Which image correctly shows the way phospholipids arrange themselves in the cell (plasma) membrane?

Transport Across a Membrane

Molecules can enter/leave the cell in 2 ways:

1.  Passive Transport

  * Diffusion

  * Facilitated (“helped”) Diffusion

  * Osmosis

2.  Active transport

  * Protein Pump

  * Endocytosis

  * Exocytosis

Passive Transport

• Energy (ATP) is NOT REQUIRED for movement of substances across the membrane

• Molecules move from an area of high concentration to an area of low concentration to reach equilibrium (same concentration on both sides)- Think of it like riding a bike downhill

Dropdown

Passive transport is the movement of particles from ​

Select answer

to ​

Select answer

concentration. 

Multiple Choice

Passive transport is called "passive" because it occurs WITHOUT

• cause.
• energy.
• a concentration gradient.
• a cell wall.

(Simple) Diffusion

• No energy is required

• Movement of molecules through a membrane to reach equilibrium

• Molecules move from area of high concentration to area of low concentration

• Occurs because molecules constantly move and collide with each other

Facilitated Diffusion

• No energy is required

• Molecules are "helped" across by carrier or channel proteins

• Molecules move from area of high concentration to area of low concentration

• Helps large or polar molecules get into the membrane

Osmosis

• No energy is required

• The diffusion of WATER through a semipermeable membrane

• Molecules move from area of high concentration to area of low concentration

Multiple Choice

Osmosis is the diffusion of _____ across a membrane

• glucose
• NaCl
• proteins
• water

Multiple Choice

Facilitated diffusion involves movement of molecules across a membrane when they bond to 

• channel proteins
• lipid proteins
• a protein pump (carrier protein)
• sticky proteins

Multiple Choice

Which type of diffusion is represented?

• Facilitated diffusion

• Osmosis

• Diffusion

Multiple Choice

Which molecule is in equilibrium? How can you tell?

• Molecule A; equal amounts inside and outside

• Molecule B; passive movement into the cell

• Molecule C; equal amounts inside and outside

• Molecule C; all molecules are inside the cell

Osmosis- Water Balance in Cells

​Isotonic Solutions	​Hypotonic Solutions	​Hypertonic Solutions
​Concentration of solutes (Dissolved substance) is the same in and out of the cell Equal amount of water leaving and entering cell	​Solution has a lower solute concentration than the inside of cell More water enters cell, causing cell to expand (get big)	​Solution has a higher solute concentration than the inside of the cell. More water leaves cell, causing cell to shrink

Osmosis- Water Balance in Cells

​Animal Cells

Plant Cells

The cell wall prevents plant cells from bursting in hypotonic solutions. Plant cells are referred to a "turgid" when like this and this helps hold plants upright.

Match

Match the following

• Hypertonic

• Hypotonic

• Isotonic

The solution contains a high concentration of solute an and low concentration of water

The solution contains a low concentration of solute an and high concentration of water

The solution has an equal concentration of solute and water compared to the inside of the cell

• The solution contains a high concentration of solute an and low concentration of water

• The solution contains a low concentration of solute an and high concentration of water

• The solution has an equal concentration of solute and water compared to the inside of the cell

Multiple Choice

The cell shrunk in size, which means it was placed in a ____ solution.

• Isotonic

• Hypertonic

• Hypotonic

Multiple Choice

In this picture, which way will the water move?

• Water will move into the cell
• Water will move out of the cell
• Water will move in and out of the cell
• Water will not move

Multiple Choice

The cell expanded in size to the point of lysing (bursting), which means it was placed in a ____ solution.

• Isotonic

• Hypertonic

• Hypotonic

Active Transport

• Energy (ATP) is REQUIRED for movement of substances across the membrane

• Molecules "pumped" from an area of low concentration to an area of high concentration against the concentration gradient- Think of it like riding a bike uphill

Multiple Choice

Active transport across a cell membrane from low to high concentration, requires

• energy (ATP)

• no energy

• water

• oxygen

Protein Pump

• Energy is required

• Protein pumps in membrane "pull" molecules through using ATP

• Molecules move from area of high concentration to area of low concentration

Endocytosis

• Energy is required

• When the cell membrane engulfs larger molecules to bring into the cell

• Molecules can move with or against the concentration gradient, depending on what the cell needs

• This is the same process certain cells in our immune system use to engulf and destroy invaders!

Exocytosis

• Energy is required

• When a membrane of a vacuole surrounding material (protein or lipids produced or waste products) fuses with the cell membrane, releasing the material outside of the cell

• Molecules can move with or against the concentration gradient, depending on what the cell needs

Match

Match the following processes to the illustration:

Diffusion

facilitated diffusion

active transport

exocytosis

endocytosis

• Diffusion

• facilitated diffusion

• active transport

• exocytosis

• endocytosis

Match

Match the following

• Simple Diffusion

• Facilitated Diffusion

• Osmosis

• Endocytosis

• Exocytosis

When molecules passively cross the plasma membrane through the phospholipid bilayer

When molecules passively cross the plasma membrane through a channel protein

The movement of water across the cell membrane

Bringing in large materials through the cell membrane into a vacuole.

Moving larger amounts or large quantities of materials through the cell membrane

• When molecules passively cross the plasma membrane through the phospholipid bilayer

• When molecules passively cross the plasma membrane through a channel protein

• The movement of water across the cell membrane

• Bringing in large materials through the cell membrane into a vacuole.

• Moving larger amounts or large quantities of materials through the cell membrane

Match

Match the following

• oxygen & carbon dioxide move into and out of blood and lungs

• insulin produced and pushed out of cell in vesicles

• cell pulls in glucose to produce ATP

• white blood cells engulf and destroy invading bacteria

• water moves out of plant cells when plant watered with salt solution

diffusion

exocytosis

active transport

endocytosis

osmosis

• diffusion

• exocytosis

• active transport

• endocytosis

• osmosis