Cellular Transport and Osmosis Vocabulary

Flashcards covering passive transport, active transport, tonicity terms, and bacterial structures based on the lecture transcript.

Simple Diffusion

The passive movement of small, nonpolar solute particles (such as $O_2$ and $CO_2$) directly through the lipid bilayer from high to low concentration without ATP or transport proteins.

Facilitated Diffusion

The passive transport of larger or polar molecules (such as glucose or ions) across a membrane down their concentration gradient using specific protein channels or carrier proteins (like GLUT transporters) without ATP.

Osmosis

The specific movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration without ATP.

Active Transport

A transport process that requires energy in the form of ATP and membrane protein pumps to move solutes against their concentration gradient from low to high concentration.

Hypotonic Solution

A solution where the solute concentration outside the cell is lower than inside, causing water to enter the cell, resulting in turgor pressure in walled cells or lysis in cells without a wall.

Isotonic Solution

A solution where the solute concentration outside the cell equals the solute concentration inside, resulting in no net water movement and maintaining a normal cell shape (e.g., $0.85\%$ NaCl).

Hypertonic Solution

A solution where the solute concentration outside the cell is higher than inside, causing water to leave the cell, leading to plasmolysis in walled cells or crenation in animal cells.

Plasmolysis

The shrinking of a cell's membrane/cytoplasm away from its cell wall in a hypertonic environment, occurring in cells with a wall such as plants and bacteria.

Crenation

The shrinking of a cell lacking a wall (such as an animal cell) in a hypertonic environment, causing it to appear shriveled and spiky.

Lysis

The bursting of a cell caused by water flowing inward when placed in a hypotonic solution, occurring only in cells without a cell wall.

Calcium Dipicolinate

A compound that protects bacterial endospores by reducing their water content and stabilizing their DNA.

Halophiles

Organisms (such as Dead Sea bacteria) adapted to hypertonic environments by balancing salt concentrations internally.

GLUT Transporters

Specific transport proteins that move glucose across the cell membrane via facilitated diffusion.