The Cell Membrane Homeostasis & Cellular Transport

The Cell Membrane

Homeostasis & Cellular Transport

Function of the Cell Membrane:

• Cell membrane separates the components of a cell from its environment—surrounds the cell
• “Gatekeeper” of the cell—regulates the flow of materials into and out of cell—selectively permeable
• Cell membrane helps cells maintain homeostasis—stable internal balance

The Cell Membrane & Homeostasis

• The cell membrane is responsible for maintaining homeostasis (home-E-O-Stay-sis) within the cell
• Homeostasis is a stable, internal environment
• The cell membrane maintains homeostasis through balancing the pH, temperature, glucose (sugar intake), water balance
• It does this through active and passive transport

In homeostasis, everything is PERFECT

pH and homeostasis

• The pH of a solution tells how acidic or basic it is.

pH ranges from a scale to 0-14

• Solutions with a pH from 0-6 are acidic
• Solutions with a pH of 8-14 are basic
• Solutions with a pH of 7 are Neutral.

If a solution’s pH is unbalanced, it is corrected with a BUFFER.

Is it Basic, Acidic, or Neutral?

• Orange juice w/ a pH of 2
• Gastric juices (stomach juices) w/ a pH of 1
• Tap water w/ a pH of 7
• Sodium hydroxide w/ a pH of 10
• Ammonia w/ a pH of 14

1 (acid)………………6 7(neutral) 8…………………14 (basic)

Cell Membrane aka “The Phospholipid Bilayer”

• ALL cells have a cell membrane made of Phosphate, proteins, and lipids
• That’s why it’s called the Phospholipid Bilayer

Cell Membrane
lipid bilayer