Chapter 6: A Tour of the Cell - Vocabulary Flashcards

Vocabulary flashcards covering key terms, organelles, microscopic techniques, and cellular structures from Chapter 6: A Tour of the Cell.

Cell

The fundamental unit of life and the simplest collection of matter that can live, from which all organisms are made.

Light Microscope

An optical instrument used to visualize whole living or fixed cells and large organelles such as the nucleus by passing visible light through the specimen.

Scanning Electron Microscope (SEM)

A microscope that uses high-energy electrons to scan the surface of a specimen, providing detailed three-dimensional images of cell surfaces.

Transmission Electron Microscope (TEM)

A microscope that passes high-energy electrons through a specimen to study the internal ultrastructure of cells in detail.

Surface Area-to-Volume Ratio

A critical relationship in cell size where volume increases by a factor of $n^3$ while surface area increases by a factor of $n^2$, limiting maximum cell size to allow sufficient material exchange.

Alexander Fleming

The scientist who discovered Penicillin by observing the bacteria-killing properties of the mold Penicillium on Staphylococcus bacteria.

Penicillin

The first discovered antibiotic, produced by Penicillium mold, which kills bacteria by targeting their cell wall structure.

Prokaryotic Cell

A type of cell found in Bacteria and Archaea that lacks a membrane-enclosed nucleus and most organelles.

Eukaryotic Cell

A type of cell found in protists, fungi, animals, and plants that is larger and more complex, featuring a membrane-enclosed nucleus and specialized membrane-bound organelles.

Nucleoid Region

The non-membrane-bounded region in a prokaryotic cell where its DNA is concentrated.

Nucleus

The genetic control center of a eukaryotic cell, containing DNA that stores instructions for making proteins.

Nuclear Envelope

A double membrane surrounding the nucleus that regulates the entry and exit of molecules through nuclear pores.

Nuclear Lamina

A net-like array of protein fibers lining and supporting the nuclear envelope to maintain the structural shape of the nucleus.

Nucleolus

A specialized structure within the nucleus responsible for producing ribosomal RNA (rRNA) and assembling ribosome subunits.

Ribosome

A cellular complex composed of ribosomal RNA and protein that synthesizes proteins by reading mRNA instructions.

Endomembrane System

A collection of eukaryotic cellular membranes—including the nuclear envelope, ER, Golgi apparatus, plasma membrane, lysosomes, and vacuoles—that are continuous or linked via transport vesicles.

Smooth Endoplasmic Reticulum

The portion of the endoplasmic reticulum that lacks bound ribosomes and functions in lipid synthesis and detoxification.

Rough Endoplasmic Reticulum

The portion of the endoplasmic reticulum studded with ribosomes on its outer surface, where synthesized proteins are deposited, folded, and modified.

Transport Vesicle

A small membrane-bound sphere that buds off from cell membranes to shuttle proteins and other products between organelles or to the plasma membrane.

Golgi Apparatus

An organelle consisting of flattened membranous sacs that receives proteins from the rough ER, modifies them, attaches chemical shipping tags, and sorts them for final destination.

Lysosome

A membrane-enclosed sac of digestive enzymes formed by the Golgi apparatus that breaks down ingested macromolecules or damaged organelles.

Phagocytosis

The cellular process of engulfing large particles or food into a food vacuole, which then fuses with a lysosome for intracellular digestion.

Autophagy

A cellular recycling mechanism in which lysosomes fuse with vesicles containing damaged organelles to break down and reuse their components.

Mitochondria

Double-membrane eukaryotic organelles present in plants, animals, fungi, and unicellular eukaryotes that serve as the sites of cellular respiration to generate ATP.

Cristae

Infoldings of the inner mitochondrial membrane that expand its surface area for cellular respiration processes.

Mitochondrial Matrix

The fluid-filled compartment enclosed by the inner mitochondrial membrane containing enzymes, mitochondrial DNA, and ribosomes.

Chloroplast

A double-membrane photosynthetic organelle found in plants and algae that contains chlorophyll and converts light energy into chemical energy.

Stroma

The fluid surrounding the thylakoids inside the inner membrane of a chloroplast, containing chloroplast DNA, ribosomes, and enzymes.

Thylakoid

A flattened, connected membranous sac inside a chloroplast arranged in stacks called grana that houses chlorophyll for absorbing light energy.

Cytoskeleton

A dynamic network of protein fibers extending throughout the cytoplasm that maintains cell shape, anchors organelles, enables intracellular transport, and aids cell motility.

Plant Cell Wall

An extracellular structure composed primarily of cellulose fibers that protects plant cells, maintains shape, and prevents excessive water uptake.

Extracellular Matrix (ECM)

A meshwork surrounding animal cells composed mainly of glycoproteins like collagen and carbohydrates that functions in cell support, tissue cohesion, and cell communication.

Plasmodesmata

Microscopic channels passing through adjacent plant cell walls that connect their cytoplasm to allow transport of water and small solutes.