Cells: Structure and Function

This set of flashcards covers key vocabulary and important concepts related to cell structure, function, and processes mentioned in the lecture notes.

Cell

The smallest unit of life that can function independently and perform all vital physiological functions.

Epithelial Cells

Cells that form the tissues covering body surfaces and cavities, serving protective and absorptive roles.

Nucleus

The membrane-bound organelle that contains the cell's genetic material (DNA) and controls its activities.

Mitochondria

Organelles that perform cellular respiration to generate ATP, the energy currency of the cell.

Cell Membrane

A selectively permeable barrier that encloses the cell, regulating the movement of substances in and out.

Endoplasmic Reticulum (ER)

A network of membranes involved in protein and lipid synthesis; can be rough (with ribosomes) or smooth (without ribosomes).

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Lysosomes

Membranous sacs containing enzymes that digest cellular waste, nutrients, and debris.

Cytoskeleton

A network of protein filaments and tubules that help maintain cell shape and facilitate movement.

Diffusion

The passive movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Facilitated Diffusion

The process of transporting substances across a membrane with the help of membrane proteins, without energy expenditure.

Osmosis

The passive movement of water across a selectively permeable membrane from a region of lower solute concentration to higher solute concentration.

Active Transport

The movement of substances against their concentration gradient, requiring energy in the form of ATP.

Endocytosis

The process by which cells internalize substances from their external environment through vesicles.

Exocytosis

The process in which a cell exports materials using vesicles that fuse with the plasma membrane to release contents outside.

Apoptosis

Programmed cell death that occurs as a normal part of growth and development.

Stem Cells

Undifferentiated cells capable of self-renewal and differentiation into various cell types.

Chromatin

The complex of DNA and proteins found in the nucleus that condenses to form chromosomes during cell division.

Cell Cycle

The series of phases that a cell goes through from formation to division, including interphase, mitosis, and cytokinesis.

Tonicity

The relative concentration of solutes in a solution that determines the direction of water movement across a membrane.

Cilia

Short, hair-like structures on the surface of many cells that aid in movement of fluids or the cell itself.

Flagella

Long, whip-like structures used for the movement of sperm cells in human reproduction.