Cell Biology: Cell Size Limits, Organelles, and the Endomembrane System

Vocabulary practice flashcards generated from the cell biology lecture notes covering cell scale, organelles, endosymbiosis, and the endomembrane system.

Goldilocks zone for cell size

The range from $1$ to $100$ micrometers (\text{̢̤̥}\text{̀́}\text{̂}\text{̃}\text{̄}\text{̅}\text{̆}\text{̇}\text{̈}\text{̉}\text{̊}\text{̋}\text{̌}\text{̍}\text{̎}\text{̏}\text{̐}\text{̑}\text{̒}\text{̓}\text{̔}\text{̕}\text{̖}\text{̗}\text{̘}\text{̙}\text{̚}\text{̛}\text{̜}\text{̝}\text{̞}\text{̟}\text{̠}\text{̡}\text{̢}\text{̣}\text{̤}\text{̥}\text{̦}\text{̧}\text{̨}\text{̩}\text{̪}\text{̫}\text{̬}\text{̭}\text{̮}\text{̯}\text{̰}\text{̱}\text{̲}\text{̳}\text{̴}\text{̵}\text{̶}\text{̷}\text{̸}\text{̹}\text{̺}\text{̻}\text{̼}\text{̽}\text{̾}\text{̿}\text{̀}\text{́}\text{͂}\text{̓}\text{̈́}\text{ͅ}\text{͆}\text{͇}\text{͈}\text{͉}\text{͊}\text{͋}\text{͌}\text{͍}\text{͎}\text{͏}\text{͐}\text{͑}\text{͒}\text{͓}\text{͔}\text{͕}\text{͖}\text{͗}\text{͘}\text{͙}\text{͚}\text{͛}\text{͜}\text{͝}\text{͞}\text{͟}\text{͠}\text{͡}\text{͢}\text{ͣ}\text{ͤ}\text{ͥ}\text{ͦ}\text{ͧ}\text{ͨ}\text{ͩ}\text{ͪ}\text{ͫ}\text{ͬ}\text{ͭ}\text{ͮ}\text{ͯ}\text{1}\text{--}\text{100}\text{ }\text{μm}) across two orders of magnitude where most cells fall.

Axon

A long, microscopically thin tail of a neuron used to send messages, which can reach up to almost an entire meter in length.

Surface area to volume ratio

The relationship between a cell's surface area and volume that dictates transport efficiency and how close any internal location is to the plasma membrane.

Nuclear genome

The majority of the DNA in a eukaryotic cell, which is sequestered within the nucleus.

Nuclear envelope

A double membrane composed of two lipid bilayers that surrounds and isolates the nuclear DNA from the rest of the cell.

Nuclear pores

Protein complexes forming regulated tunnels across the nuclear envelope to control transport between the nucleoplasm and cytoplasm.

Nucleoplasm

The internal substance and fluid contents contained entirely within the nucleus.

Endosymbiosis

An evolutionary process wherein a larger cell engulfs a smaller cell that avoids digestion and becomes integrated as an organelle.

Mitochondria

Organelles found in all eukaryotic lineages that perform aerobic respiration, derived from engulfed aerobic bacteria via endosymbiosis.

Chloroplasts

Photosynthetic organelles containing three membrane systems, derived via endosymbiosis from cyanobacteria and present in plants and algae.

Binary fission

The process of division utilized by bacteria as well as endosymbiotic organelles like mitochondria and chloroplasts.

Ribosomes

Non-membrane-bound structures composed of RNA and protein that carry out protein synthesis.

Endomembrane system

An integrated internal network of membrane-bound organelles that coordinate transport and biochemical processes inside eukaryotic cells.

Lumen

The general term for the innermost enclosed space or compartment inside an organelle, membrane structure, or biological vessel.

Direct continuity

A structural setup where two membrane-bound areas share a single, unbroken internal space or lumen.

Vesicular transport

The movement of materials and membrane lipids between isolated cellular compartments using small membrane bubbles called vesicles.

Rough endoplasmic reticulum (Rough ER)

A region of the endoplasmic reticulum studded with ribosomes that specializes in protein synthesis, modification, and transport.

Smooth endoplasmic reticulum (Smooth ER)

A region of the endoplasmic reticulum lacking ribosomes that specializes in lipid synthesis and metabolism.

Golgi apparatus

An organelle made of stacked, distinct flat compartments that receives proteins from the ER, modifies them, and sorts them for transport.

Vacuoles

Large, long-lived membrane-bound structures derived from the endomembrane system that function primarily in storage or osmoregulation.

Lysosomes

Digestive organelles containing hydrolytic enzymes that break down macromolecules and function optimally under acidic conditions.