Cell Transport

Flashcards about cell transport

What type of transport requires energy to move molecules against a concentration gradient?

Active Transport

Name three molecules that can move across the phospholipid membrane.

Oxygen, glucose, and carbon dioxide

List three factors that can affect the movement of substances across the plasma membrane.

Size, concentration, and chemical composition (charge)

Does passive transport require additional energy from the cell?

No, some energy is needed, but not additional.

How do molecules move along a concentration gradient during passive transport?

From an area of high concentration to an area of low concentration

What does hydrophobic mean?

Doesn’t mix with water (fears water)

Give two examples of small hydrophobic molecules.

Oxygen and carbon dioxide

What is the term used to describe the diffusion of water molecules through a plasma membrane?

Osmosis

Define diffusion.

Movement of molecules from high concentration to low concentration until an equilibrium is reached

What two characteristics must a molecule have to be moved across the plasma membrane via diffusion?

Small enough to fit between the phospholipids and hydrophobic

What is facilitated diffusion?

The movement of molecules across the cell membrane via transport proteins

How do protein channels and carrier proteins help move substances through the plasma membrane?

Carrier proteins bind to specific molecules and change shape to transport them. Channel proteins allow ions to pass through.

Is additional energy required for facilitated diffusion?

No

Define osmosis.

The passive movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.

What is an isotonic environment?

The fluids inside and outside the cell are of equal solute concentration, no net movement of water.

What is a hypotonic environment?

The solution outside the cell has a lower solute concentration, net movement of water into cell

What is a hypertonic environment?

The solution outside the cell has a higher solute concentration, net movement of water out of cell.

Describe exocytosis.

The process of moving substances out of a cell.

Describe endocytosis.

The process of moving substances into a cell. Cells engulf extracellular material by folding its plasma membrane around the material to create a vesicle.

What are the two types of endocytosis?

Phagocytosis (engulfing solids) and Pinocytosis (engulfing liquids)