Cell Structure Quiz

Study Notes

Human cells are fundamental units that comprise tissues, organs, and systems.
Each cell has a plasma membrane, cytoplasm, and various organelles, including the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and centrioles.

Composed of two flexible lipid layers resembling olive oil in consistency.
Includes embedded proteins and sugar molecules that facilitate communication with internal and external environments.
Differentiates between intracellular fluid (inside the cell) and extracellular fluid (outside the cell).
Allows for cell-to-cell communication and protects organelles.
Layers consist of lipids (phospholipids, cholesterol), proteins, and carbohydrate groups.

The area between the nucleus and the plasma membrane where most cellular activity occurs.
Contains cytosol, a viscous liquid mainly made of water, proteins, sugars, salts, and other solutes.
Hosts organelles and chemical substances specific to the cell's function.

The largest organelle, acting as the control center of the cell.
Houses DNA, which serves as genetic material essential for directing metabolic activities and protein synthesis.
Typically contains one nucleus per cell, with exceptions in muscle and liver cells, which might have multiple, while red blood cells eject their nucleus.

Small cylindrical organelles arranged in pairs, positioned perpendicularly near the nucleus.
Composed of microtubules, crucial for cell division by forming spindles.

Four primary mechanisms of cellular communication are identified:
- Direct contact: Recognition of surface molecules by adjacent cell receptors.
- Paracrine communication: Local signals affecting neighboring cells, significant in cell growth.
- Endocrine communication: Hormone signals released into the bloodstream that influence distant cells.
- Synaptic communication: Neurotransmitters released by nerve cells that bind to receptors on nearby neurons.