Bio Slides M1D1

Vocabulary flashcards covering core transport principles, Fick's Law, water potential components, membrane transport types, and body size scaling from the Organismal Form & Function lecture.

Fick's Law of Diffusion

The relationship governing the rate of diffusion, expressed as $F \propto A \frac{C_1 - C_2}{d}$, where $F$ is the rate of diffusion, $A$ is surface area, $C_1 - C_2$ is the concentration difference, and $d$ is diffusion distance.

Electrochemical Equilibrium

The state reached when the combination of concentration gradient and electrical gradient across a membrane is balanced, also known as Donnan equilibrium.

Osmosis

The net movement of water across a membrane down its concentration gradient.

Osmolarity

The measure of solute concentration determined by the combined concentration of all solutes in a solution.

Electrochemical Gradient

Diffusion of charged particles depends on combination of concentration and electrical gradient

Osmotic Pressure

A pressure that is proportional to the difference in osmolarity between two solutions.

Isosmotic

A term describing two solutions that have the exact same osmolarity.

Hyperosmotic

A term describing a solution that has a higher solute concentration than another solution.

Hyposmotic

A term describing a solution that has a lower solute concentration than another solution.

Water Potential

The overall tendency of water to move between locations, calculated as $\Psi = \Psi_P + \Psi_S + \Psi_M$, where water moves from areas of higher potential to lower potential.

Hydrostatic pressure

The physical pressure exerted by a fluid, which serves as the pressure potential component of total water potential and is typically a positive value.

Osmotic pressure

The pressure proportional to the difference in osmolarity between two solutions, represented in water potential equations as solute potential, which is normally negative.

Water cohesion and adhesion

Normally negative

Pressure Potential

The hydrostatic pressure component of water potential, which is normally positive.

Solute Potential

The osmotic pressure component of water potential, which is normally negative.

Matrix Potential

The component of water potential resulting from water cohesion and adhesion, which is normally negative.

Phospholipid Bilayer

A biological membrane composed of two lipid layers with a hydrophobic core, exhibiting selective permeability with different diffusion rates for substances based on their size and charge.

Primary Active Transport

Direct movement of a solute across a cell membrane against its concentration gradient using energy supplied directly by an ATP-powered pump.

Secondary Active Transport

Movement of a solute against its gradient powered by the cotransport of another solute moving down its gradient, which was previously pumped using ATP.

Surface Area to Volume Ratio Scaling

The geometric principle stating that as body length ($L$) increases, surface area increases in proportion to $L^2$ while volume increases in proportion to $L^3$, causing a decrease in the $SA:V$ ratio.

Plasmolysis

The shrinking of a plant cell membrane away from its cell wall when placed in a hypertonic solution.

Concentration Gradient

Particles tend to move from high to low

Electrical Gradient

Opposite charges attract

Same charges repel