BIO 1101 Cell Transport

These flashcards cover the vocabulary and key concepts of cell transport mechanisms, including active and passive transport, diffusion types, and filtration, as presented in BIO 1101.

Active Transport

A transport mechanism that requires energy in the form of $ATP$ to move substances from low concentration to high concentration, analogous to pushing a ball up a hill.

Passive Transport

A transport mechanism where no energy is required and substances move from high concentration to low concentration, analogous to allowing a ball to roll down a hill.

Simple Diffusion

The movement of small substances across the plasma membrane from an area of high concentration to an area of low concentration.

Facilitated Diffusion

A passive mechanism involving carrier proteins to transport larger substances into or out of the cell from high to low concentration.

Filtration

A process where water and solutes are forced through a membrane due to a pressure gradient, such as the first process in producing urine in the kidney.

Non-polar (uncharged) substances

Substances that move directly across the phospholipid bilayer during simple diffusion because they are lipid soluble.

Polar (charged) substances

Water-soluble molecules that cannot diffuse through the phospholipid bilayer and must move through a protein channel or pore in the membrane.

Molecular Mass

A factor where decreased molecular size or mass increases the rate of transport, meaning lighter molecules diffuse faster than heavier ones.

Polarity

A factor influencing the rate of diffusion where non-polar (lipid soluble) molecules pass more easily through the cell membrane.

Carrier proteins

Membrane proteins used in facilitated diffusion; the rate of transport increases as the number of these proteins increases.

Concentration Gradient

The difference in concentration between two areas; passive transport occurs when substances move "down" this gradient from high to low concentration.

ATP

The form of energy required to power active transport mechanisms.