Cell Structure and Membrane Functions

These flashcards cover key terms and concepts related to cell structure and function, focusing on membranes and organelles.

Nucleus

The organelle that contains the cell's DNA, protecting it and regulating what goes in and out.

Nuclear Pores

Holes in the nuclear membrane that allow certain substances to enter and exit the nucleus.

Endoplasmic Reticulum (ER)

A network of membranes involved in the synthesis of lipids and proteins.

Ribosomes

Small structures on the rough ER that synthesize proteins.

Golgi Apparatus

The organelle that modifies, sorts, and packages proteins and lipids for transport.

Lysosome

An organelle containing digestive enzymes, responsible for breaking down macromolecules.

Mitochondria

Organelles that generate ATP, the energy currency of the cell.

Cytoskeleton

A network of fibers that helps the cell maintain its shape and aids in movement.

Extracellular Matrix

A network outside the cell composed of proteins and carbohydrates that provide structural and biochemical support.

Plasma Membrane

The membrane surrounding the cell, composed of a phospholipid bilayer that controls the movement of substances in and out.

Phospholipid Bilayer

A double layer of phospholipids that makes up the plasma membrane, with hydrophilic heads facing outward and hydrophobic tails inward.

Hydrophilic

Water-attracting; describes parts of molecules that interact with water.

Hydrophobic

Water-repelling; describes parts of molecules that do not interact with water.

Fluid Mosaic Model

A model describing the structure of the plasma membrane as flexible and composed of various proteins embedded within the lipid bilayer.

Integral Proteins

Proteins that span across the plasma membrane; also known as transmembrane proteins.

Peripheral Proteins

Proteins associated with the outer or inner surface of the membrane, not embedded within it.

Glycoproteins

Proteins with carbohydrate chains attached, involved in cell recognition and signaling.

Facilitated Diffusion

The process of passive transport of molecules across the cell membrane via protein channels.

Active Transport

The movement of molecules against their concentration gradient, requiring energy (ATP).

Sodium-Potassium Pump

A carrier protein that actively transports sodium out of the cell and potassium into the cell.

Diffusion

The passive movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Hypertonic Solution

A solution with a higher concentration of solute compared to another solution.

Hypotonic Solution

A solution with a lower concentration of solute compared to another solution.

Isotonic Solution

A solution with an equal concentration of solute compared to another solution.