How do Materials Move Across the Cells Membrane

How do Materials Move Across the Cell’s Membrane

Cell Transport • Metabolism • The set of chemical reactions that happen in living organisms to maintain life. • Homeostasis • The ability of an organism or cell to maintain an internal balance by adjusting its processes.

Cell Membrane • The cell’s membrane is selectively permeable. • Selective permeability means that some substances can pass through while others are restricted from entering. • Selective Permeability

Selective Permeability • So what are some things that may pass into or out of the cell? • What controls what enters and leaves the cell?

Passive Transport • When materials move without using the cell’s energy. • Two Types of passive transport: Diffusion and Osmosis

Diffusion • The process by which molecules spread out, or move from areas of high concentration to low concentration.

Diffusion • The process by which molecules spread out, or move from areas of high concentration to low concentration.

Diffusion in the Cell • The movement of materials across the cell membrane without any input of energy by the cell • Diffusion and Passive Transport

Osmosis • The diffusion of water through a membrane. • Osmosis is a form of passive transport. • Can anyone think of a time when you experience osmosis?

Osmosis

How does passive transport affect cells? • If the concentration of water and dissolved materials INSIDE the cell is different than the concentrations OUTSIDE the cell…

Osmosis • What is wrong about this picture? IF there was more knowledge in the books than there was in Garfield and information could be passed this way, how would he be learning? Osmosis in the Kitchen

Active Transport • The movement of materials across the cell membrane where the cell must use energy to move the materials.

Active Transport • Two types of Active Transport: • Endocytosis – when large materials move into the cell. • Exocytosis – when large materials move out of the cell.

Endocytosis • Endocytosis – Two Types: • Pinocytosis = liquid moving into cell • Phagocytosis = solid moving into cell

Active Transport - Exocytosis • The process by which cells excrete material by surrounding the material with a pocket of membrane which move towards and joins with the cell membrane to expel the material outside the cell. • Simply… it’s reverse endocytosis

Endocytosis and Exocytosis • Endocytosis and Exocytosis

Passive Transport • The movement of materials across the cell membrane without any input of energy by the cell • 2 Types of Passive Transport • Diffusion • Osmosis

Diffusion • Simplest type of passive transport • No energy from cell • HIGH to LOW concentration • Molecules bounce off of each other until they spread out equally

Diffusion

Osmosis • The diffusion of water. • No energy from cell • HIGH to LOW concentration • Diffusion of water and dissolved substances

Active Transport • The movement of materials across the cell membrane where the cell must use energy to move the materials • 2 Types of Active Transport • Endocytosis • Exocytosis

Endocytosis • Large molecules brought INTO the cell. • Requires energy from the cell • 2 Types of endocytosis • Pinocytosis = liquid coming into cell • Phagocytosis = solid coming into cell

Exocytosis • Large molecules taken OUT OF the cell. • Requires energy from the cell • This is how cells release the products made by the organelles