Lesson 1: Cell Biology

Vocabulary flashcards summarizing key organelles, processes, and terms introduced in the lecture on human eukaryotic cells and their functions.

Cell Biology

The branch of biology that studies cellular structures, functions, and processes.

Eukaryotic Cell

A cell type with a membrane-bound nucleus and membrane-bound organelles; characteristic of human cells.

Plasma Membrane

A phospholipid bilayer that encloses the cell, maintains shape, and regulates molecule movement in and out.

Cytoplasm

The aqueous solution of water, salts, and dissolved molecules in which cellular organelles are suspended.

Nucleus

Membrane-bound control center housing most genetic material (DNA) and directing cellular activities.

Nuclear Envelope

Double membrane with pores that separates nuclear contents from the cytoplasm and controls exchange.

Ribosome

RNA-rich particle (free or on RER) that translates RNA into proteins during protein synthesis.

RNA (Ribonucleic Acid)

Nucleic acid that carries genetic instructions from DNA for protein synthesis.

Endoplasmic Reticulum (ER)

Network of membranous tubules continuous with the nuclear envelope; subdivided into rough and smooth regions.

Rough Endoplasmic Reticulum (RER)

ER studded with ribosomes; site of protein synthesis and initial protein modification.

Smooth Endoplasmic Reticulum (SER)

ER lacking ribosomes; synthesizes lipids, steroid hormones, and regulates intracellular calcium.

Golgi Complex (Golgi Apparatus)

Stacked membranes that modify, package, and ship proteins and lipids received from the RER.

Lysosome

Membrane-bound vesicle filled with digestive enzymes that degrades waste, pathogens, or malfunctioning molecules.

Mitochondrion

Bean-shaped organelle with folded inner membrane (cristae) that produces ATP via aerobic respiration.

ATP (Adenosine Triphosphate)

High-energy molecule generated mainly in mitochondria; primary energy currency of the cell.

Aerobic Respiration

Oxygen-requiring metabolic pathway in mitochondria that converts nutrients into ATP, CO₂, and water.

Phagocytosis

Cellular process in which specialized cells engulf and internalize large particles or microbes for destruction.

Autophagy

Self-eating process where a cell breaks down its own damaged organelles or proteins, often via lysosomes.

Cilium (plural: Cilia)

Short, hair-like projection on cell surfaces that beats in coordinated waves to move fluid or mucus.

Flagellum (plural: Flagella)

Long, whip-like appendage (e.g., on sperm) that propels a cell through its environment.

Cellular Differentiation

Process by which cells develop specialized structures and functions based on gene expression patterns.

Chromatin

DNA-protein complex in the nucleus that condenses into chromosomes during cell division.