Unit 2 - Cell Structure

Microscope

An instrument that magnifies an object.

Light Microscope

Produces magnified images by focusing visible light rays.

Compound Light Microscope

Allows light to pass through an image and uses two lenses.

Fluorescence Microscopy

A technique used to identify the location of molecules in cells using fluorescent stains.

Electron Microscope

Produces magnified images by focusing beams of electrons.

Transmission Electron Microscope

Explores cell structures and large protein molecules.

Scanning Electron Microscope

Produces three-dimensional images of a specimen’s surface.

Cell Theory

States that all living things are made of cells, the cell is the basic unit of life, and cells come from pre-existing cells.

Prokaryotic Cell

A simple, mostly single-celled organism that lacks a nucleus.

Common Components of Prokaryotic Cells

Plasma membrane, cytoplasm, DNA, and ribosomes.

Capsule

Enables the cell to attach to surfaces in its environment.

Flagella

Used for locomotion in prokaryotic cells.

Pili

Used to exchange genetic material during conjugation.

Eukaryotic Cells

Cells that have a membrane-bound nucleus and organelles.

Organelle

Little organ; specialized structures within a cell that perform distinct functions.

Plasma Membrane

A phospholipid bilayer that separates the internal contents of the cell from its surrounding environment.

Cytoplasm

The entire region of a cell between the plasma membrane and the nuclear envelope.

Nucleus

Houses the cell’s DNA and directs the synthesis of ribosomes and proteins.

Nuclear Envelope

Double membrane structure that constitutes the outermost portion of the nucleus.

Chromatin

Unwound protein-chromosome complex found within the nucleus.

Ribosomes

Cellular organelles responsible for protein synthesis.

Mitochondria

Organelles responsible for energy production in the form of ATP.

Peroxisomes

Organelles that carry out oxidation reactions and detoxify many poisons.

Vesicles

Membrane-bound sacs that function in transport and storage.

Vacuoles

Membrane-bound sacs that primarily function in storage.

Centrosome

A microtubule-organizing center found near the nuclei of animal cells.

Lysosome

The cell's garbage disposal; enzymes aid in breakdown of cellular waste.

Cell Wall

Rigid covering that protects and offers structural support to plant, fungal, and protistan cells.

Chloroplasts

Plant cell organelles that carry out photosynthesis.

Endosymbiosis

A mutually beneficial relationship in which one organism lives inside another.

Endomembrane System

A group of membranes and organelles that modify, package, and transport lipids and proteins.

Endoplasmic Reticulum (ER)

Interconnected and membranous sacs and tubules that modify proteins and synthesize lipids.

Rough ER

Synthesis proteins that are transferred into its lumen for modifications.

Smooth ER

Synthesizes carbohydrates, lipids, and detoxifies medications.

Golgi Apparatus

Sorts, tags, packages, and distributes lipids and proteins.

Cytoskeleton

Maintains the shape of the cell and secures organelles in specific positions.

Microfilaments

Filaments that function in cellular movement.

Intermediate Filaments

Structural components of the cytoskeleton.

Microtubules

Provide structural support and facilitate transport within the cell.