Year 11 Biology: Active Transport

These flashcards cover key concepts related to active transport, passive transport, and related cellular processes.

What is osmosis?

The movement of water molecules across a selectively permeable membrane from a region of lower solute concentration to a region of higher solute concentration.

Define hypertonic solution.

A solution having a higher solute concentration than its surroundings.

What happens to a potato slice placed in a hypertonic solution over 24 hours?

The potato shrivels and loses mass because water moves out of the potato.

What drives active transport?

Active transport requires energy in the form of ATP to move molecules against their concentration gradient.

Describe the difference between endocytosis and exocytosis.

Endocytosis is the process of moving materials into the cell, while exocytosis is the process of moving materials out of the cell.

What is phagocytosis?

A form of endocytosis known as 'cell eating', where the cell membrane surrounds and engulfs material.

What type of transport does the sodium-potassium pump represent?

Active transport, since it moves Na+ ions out of and K+ ions into the cell against their concentration gradients.

What is the significance of exocytosis in neurons?

Exocytosis is how neurons communicate, as it allows the release of chemical messengers from synapses.

What is the endosymbiotic theory?

A theory explaining the origin of eukaryotes, proposing that they evolved from a symbiosis between different prokaryotic organisms.

What are the characteristics of passive transport?

It does not require energy, moves substances down their concentration gradient, and includes processes like diffusion and osmosis.