Chapter 1–7 Review: Basic Transport, Osmosis, Diffusion, Tonicity, Filtration, pH and Buffers

Flashcards covering Brownian motion, solute/solvent concepts, diffusion (simple and facilitated), osmosis, tonicity (isotonic/hypertonic/hypotonic), filtration and hydrostatic pressure, pH, acids/bases, buffers, bicarbonate, and basic macromolecule terminology as discussed in the lecture notes.

What is Brownian motion and how does it relate to diffusion?

Brownian motion is the random zigzag movement of particles due to collisions; this random motion drives diffusion by dispersing particles.

What is a solute?

The substance being dissolved; the dispersed particles or 'stuff' in a solution.

What is a solvent?

The medium in which the solute is dissolved; typically water.

How does temperature affect the rate of diffusion?

Higher temperature increases particle movement and diffusion rate; cooler temperatures slow diffusion.

What is passive transport?

Movement from a higher concentration to a lower concentration that does not require cellular energy.

What is simple diffusion?

Diffusion of solute from an area of higher concentration to an area of lower concentration without energy or membrane proteins.

What is facilitated diffusion?

Diffusion that requires a membrane protein (gatekeeper) but does not use energy.

What is osmosis?

Movement of solvent (water) across a selectively permeable membrane to balance solute concentrations.

What is a selectively permeable membrane?

A membrane that allows some substances to pass and restricts others, enabling osmosis.

In diffusion vs. osmosis, which moves solute and which moves solvent?

Diffusion moves solute (particles); osmosis moves solvent (water).

What does isotonic mean?

Equal solute concentrations inside and outside the cell; no net water movement.

What does hypertonic mean?

Higher solute concentration on one side relative to the other; water tends to move out of the less concentrated side, causing shrinkage if outside the cell.

What does hypotonic mean?

Lower solute concentration on one side relative to the other; water tends to move into the more concentrated side, causing swelling.

What happens to a cell in a hypotonic solution?

Water enters the cell; the cell swells and may burst (lysis) if the difference is large.

What happens to a cell in a hypertonic solution?

Water leaves the cell; the cell shrinks (crenation).

What happens to a cell in an isotonic solution?

No net movement of water; the cell maintains its size.

What is filtration?

Movement of particles driven by hydrostatic (water) pressure from higher to lower pressure.

What is hydrostatic pressure?

Pressure exerted by a fluid due to gravity that drives filtration (water pushing particles through).

What is pH?

A measure of hydrogen ion concentration; pH scales from 0 to 14 with 7 as neutral.

What characterizes acids on the pH scale?

High hydrogen ion concentration; low pH.

What characterizes bases (alkaline) on the pH scale?

Low hydrogen ion concentration; high pH.

What is the typical pH range of healthy human blood?

About 7.35 to 7.45 (roughly 7.4).

What is a buffer?

A substance that resists changes in pH by binding or releasing hydrogen ions to stabilize pH.

What is bicarbonate?

A buffering ion in the blood that helps maintain pH by buffering hydrogen ions.