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

• some substances cross and others not

• Selective Permeability

• bound loosely to surface of membrane

• Amphipathic

• molecules both hydrophobic & philic part

• Peripheral proteins

• spans the membrane

• Integral Proteins

• proteins that penetrate lipid bilayer

• Transmembrane proteins

Match vocab words to their definitions

• shuttle across by changing shape

• Aquaporins

• transport proteins move with con. grad.

• Diffusion

• facilitates water passage

• Carrier proteins

• a tunnel substances can use to cross PM

• Channel proteins

• molecules spread out evenly in space

• Facilitated diffusion

Match the following vocabulary words with the definition

• from high to low concentration

• Concentration Gradient

• molecules move both directions equally

• Dynamic Equililbrium

• movement with conc. grad. and no energy

• Osmosis

• diffusion of water

• Passive transport

Tags

NGSS.MS-LS2-3

Match the following vocab words with the definition

• Concentration is greater inside than out

• Tonicity

• concentration greater out than inside

• Hypotonic

• solution causes cell to gain/loose water

• Hypertonic

• control of concentration and water

• Isotonic

• concentration same in and out

• Osmoregulation

Tags

NGSS.HS-LS1-3

Match the following vocab words with definitions

• transport protein generates voltage

• Membrane Potential

• substances move against conc. grad.

• Electrogenic Pump

• 1 molecule with gradient and other not

• Cotransport

• unequal dist. of anions and cations

• Active Transport

Match the following Vocab words with their definitions

• vesicles bond with PM and release bulk

• Endocytosis

• cell eating

• Pinocytosis

• cell drinking

• Exocytosis

• uses receptors to engulf specific mol.

• Receptor mediated endocytosis

• takes in bulk molecules and pinches off

• Phagocytosis

Match word with definition

• acts as gate for ions

• Ligand-gated ion channel

• detection of signal

• Response

• signal molecule

• Ligand

• conversion of signal to response

• Reception

• cell activity as response to signal

• Transduction