Plasma Membrane

Cell Membrane

A phospholipid bilayer with proteins that separate the internal contents from its surroundings environment, which regulates the ins and outs of organic molecules, ions, and water with its selective permeability

Key Figures in Cell Membrane

Phospholipid, Protein, Cholesterol, Carbohydrates

Characteristics of Phospholipid

It creates a nonpolar environment in between phospholipids (away from the water) and poplar environment outside of the phospholipids

Characteristics of Protein

It can be found on or in the cell membrane. The integral proteins (those inside of the membrane) open or close, allowing larger molecules to be in or out. The peripheral proteins (those outside of the membrane) acts as enzymes that speed up reaction

Characteristics of Cholestrol

It influences the movement of phospholipids, like pushing phospholipids away if they are too close in a cold environment or pulling phospholipids in if they are too far away in a hot environment

Characteristics of Carbohydrates

It allows cells to recognize each other to allow the molecules in by either binding to proteins (glycoproteins) or lipids (glycolipids), which becomes essential in terms of blocking pathogens

Passive Transport

Naturally occurring phenomenon that does not require energy for cell movement

Active Transport

Mechanisms that require energy (ATP) for cell movement

Examples of Passive Transport

Osmosis, Diffusion, Facilitated Diffusion

Osmosis

The transport of water through a semipermeable membrane from a high concentration to low across the membrane

Diffusion

Net of movement of a substance that travels down from high concentration to low across its concentration gradient

Facilitated Diffusion

Similarly to diffusion, it’s a movement of substances that travels down from high concentration to low, but it uses integral proteins as channels to pass thtough

Active Transport

Movement of molecules that uses ATP to force the direction the molecules are moving, which disrupts the natural flow of movement

Tonicity

Amount of solutes in a solution, which correlates to osmolarity; solutes (salt) can be dissolved by water, which attracts water to higher solute concentration

Hypertonic

High concentration of solutes and Low concentration of water

Isotonic

Equal concentrations of solutes and water

Hypotonic

Low concentration of solutes and High concentration of water

How does Tonicity affect Red Blood Cells?

• Hypertonic water + RBC = shriveling

• Isotonic water + RBC = no effect

• Hypotonic water + RBC = bursting

Endocytosis

Active transport that takes particles inside the cell

Examples of Endocytosis

Phagocytosis, Pinocytosis, Receptor Mediated Endocytosis

Phagocytosis

Process of cells stretching out to engulf large particles (vore)

Pinocytosis

The process of “drinking cells” by taking multiple small molecules all at once (polyamorous + size difference vore)

Receptor-Mediated Endocytosis

Has receptors that only specific molecules to then engulf the molecules (demisexual vore)

Exocytosis

Active transport that takes molecules out of the cell by opening the plasma membrane to release them