Plasma Membrane and Cell Signaling

Please write a paragraph connecting the following vocabulary terms together: Membrane, Aquaporins, Exocytosis, and Active Transport.

Explain what a selectively permeable membrane is and what features of the cell membrane allows it to be selectively permeable.

Answer explanation

A membrane that is selectively permeable allows some substances to cross the membrane but not others. This allows the cell to regulate what flows in and out of the cell. Most substances that can flow through phospholipid bilayer of the membrane are small and non-polar. Larger and polar molecules need other features of the membrane to cross through facilitated diffusion. These features are transport proteins, for which there are a few different kinds. Channel proteins are hydrophilic passages that allow for the polar molecules to flow through with their concentration gradient. One example of a channel protein is the aquaporin, which allows for water to pass in and out of the cell. Carrier proteins work with specific molecules and change shape to shuttle them across the membrane. Transport proteins can also be used to move molecules against their concentration gradient, but this requires energy and is referred to as active transport.

Compare and contrast active and passive transport.

Answer explanation

Active and passive transport are similar in many ways. Both types of transport move substances across the plasma membrane of the cell and can involve transport proteins. Active and passive transport are different because active transport requires energy in the form of ATP to move the substances and passive does not. Additionally, passive transport moves molecules with its concentration gradient and active moves against.

Match the vocab word with its definition

• bound loosely to surface of membrane

• Transmembrane proteins

• some substances cross and others not

• Selective Permeability

• molecules both hydrophobic & philic part

• Integral Proteins

• spans the membrane

• Peripheral proteins

• proteins that penetrate lipid bilayer

• Amphipathic

Match vocab words to their definitions

• facilitates water passage

• Facilitated diffusion

• shuttle across by changing shape

• Diffusion

• transport proteins move with con. grad.

• Aquaporins

• a tunnel substances can use to cross PM

• Carrier proteins

• molecules spread out evenly in space

• Channel proteins

Match the following vocabulary words with the definition

• molecules move both directions equally

• Dynamic Equililbrium

• movement with conc. grad. and no energy

• Concentration Gradient

• from high to low concentration

• Osmosis

• diffusion of water

• Passive transport

Tags

NGSS.MS-LS2-3

Match the following vocab words with the definition

• concentration same in and out

• Osmoregulation

• control of concentration and water

• Hypertonic

• concentration greater out than inside

• Hypotonic

• solution causes cell to gain/loose water

• Isotonic

• Concentration is greater inside than out

• Tonicity

Tags

NGSS.HS-LS1-3

Match the following vocab words with definitions

• 1 molecule with gradient and other not

• Membrane Potential

• unequal dist. of anions and cations

• Electrogenic Pump

• substances move against conc. grad.

• Active Transport

• transport protein generates voltage

• Cotransport

Match the following Vocab words with their definitions

• vesicles bond with PM and release bulk

• Endocytosis

• uses receptors to engulf specific mol.

• Pinocytosis

• cell drinking

• Receptor mediated endocytosis

• cell eating

• Phagocytosis

• takes in bulk molecules and pinches off

• Exocytosis

Match word with definition

• cell activity as response to signal

• Ligand-gated ion channel

• detection of signal

• Response

• acts as gate for ions

• Ligand

• conversion of signal to response

• Transduction

• signal molecule

• Reception