SBP1

Prokaryote

A smaller, simpler cell type common to bacteria; unicellular and 1-60 microns in size.

Eukaryote

A larger, more complex cell type that has organelles and chromosomes; can be multicellular and includes animal and plant cells.

Capsule

A slimy outer coating in prokaryotes for protection and attachment.

Cell wall

A tough middle layer in prokaryotes and plant cells that provides structural support.

Cell membrane

A delicate, selective, semi-permeable skin around the cytoplasm; found in all cells.

Cytoplasm

The inner liquid filling of a cell, responsible for its fluid, gel-like nature.

DNA

Genetic material; in prokaryotes, it is arranged in one big loop.

Pili

Hair-like structures on prokaryotes for sticking onto surfaces.

Flagella

Whip-like structures used for swimming in some cells.

Ribosomes

Cellular structures that build proteins from amino acids; made of RNA.

Organelles

Membrane-bound structures in eukaryotic cells; "mini organs" with specific functions.

Nucleus

A membrane-bound sac that stores chromosomes (DNA); the command center of the cell; has pores.

Nuclear envelope

The double membrane that encloses the nucleus.

Nuclear pore

Holes in the nuclear envelope that allow materials like mRNA to pass.

Nucleolus

A structure inside the nucleus where ribosomes are assembled; made of RNA.

Mitochondrion

Organelle that produces the cell's energy (ATP).

Endoplasmic Reticulum (ER)

An organelle that may be smooth (no ribosomes) or rough (with ribosomes).

Golgi Apparatus / Golgi Complex / Golgi Bodies

Organelles that process, modify, and package materials from the ER into vesicles for transport.

Lysosomes

Organelles filled with digestive enzymes; break down waste, worn-out cells, and absorbed food; "suicide bag of the cell."

Centrioles

Paired bundled tubes that help organize cell division in animal cells.

Cytoskeleton

A network of microtubules that gives shape to the cell and moves organelles around inside.

Vacuole

A huge, water-filled sac in plant cells that stores substances like starch and keeps the cell pressurized.

Chloroplasts

Organelles filled with chlorophyll; turn solar energy into food energy (photosynthesis).

Cell wall (plant)

A very strong, cellulose-based structure that protects plant cells from rupturing and is glued to other cell walls.

Phospholipid

A lipid molecule with a water-loving (hydrophilic) head; the key structural component of cell membranes.

Fluid Mosaic Model

Model describing the cell membrane's structure where lipids and proteins can move freely.

Diffusion

Passive movement of molecules from an area of high concentration to low concentration.

Osmosis

The diffusion of water through a semi-permeable membrane.

Facilitated Diffusion

Passive transport of molecules across the membrane through protein channels.

Active Transport

Movement of molecules against the concentration gradient, requiring energy (ATP).

Anton Van Leeuwenhoek

Father of Microbiology; discovered bacteria in 1676.

Robert Hooke

English scientist who published "Micrographia," first observed and named "cells" in cork.

Matthias Schleiden

German botanist who concluded that plants are made of cells.

Theodor Schwann

German zoologist who concluded that all animals are made of cells.

Rudolph Virchow

German pathologist who proposed that all cells come from pre-existing cells.

Cell Theory

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

Microscope

An instrument that produces a magnified image of tiny structures.

Ocular Lens (Eyepiece)

The lens at the top of the microscope that you look through; typically 10X magnification.

Objective Lens

The primary lenses that magnify the specimen (e.g., 4X, 10X, 40X, 100X).

Revolving Nose Piece

The rotating part that holds the objective lenses.

Stage

The platform where the specimen slide is placed.

Stage Clip

Clips on the stage that hold the glass slide in place.

Diaphragm (Iris)

Controls the amount of light that reaches the specimen.

Condenser

Lenses that collect and focus light from the illuminator onto the specimen.

Illuminator

The light source of the microscope.

Coarse Adjustment Knob

A large knob used for rough focusing, primarily under low power.

Fine Adjustment Knob

A smaller knob used for fine-tuning the focus, especially under high power.

Base

The bottom support of the microscope.

Arm

The curved part used for carrying the microscope.

Total Magnification

Calculated by multiplying the eyepiece magnification by the objective lens magnification (e.g., 10X eyepiece * 40X objective = 400X total magnification).

Field of View (FoV)

The diameter of the visible area when looking through the microscope.

Field Number (FN)

The diameter of the image area (in mm) visible through the eyepiece; inscribed on the eyepiece.

FoV Equation

Field of View (mm) = Field Number (FN) / Objective Magnification.

Resolution

The sharpness or clarity of an image; the ability to distinguish two close objects as separate.

TEM (Transmission Electron Microscope)

A microscope that uses electrons to produce a detailed 2D, black-and-white image; requires very thin samples.

SEM (Scanning Electron Microscope)

A microscope that uses electrons to scan a sample's surface, producing a 3D image.

Stereo / Dissecting Microscope

A microscope used for viewing large, solid specimens in 3D; has a great working distance but lower magnification.

Pseudopods

"False feet"; extensions of the cell membrane used by some cells (e.g., amoeba) for crawling.

Cilia

Fine, hairlike extensions attached to the cell membrane that beat in unison for movement or to move fluid.

Flagellum/Flagella

A large, whiplike tail used to push or pull a cell through water.

Endosymbiont Theory

A theory popularized by Lynn Margulis stating that eukaryotic organelles like mitochondria and chloroplasts evolved from smaller prokaryotes that were engulfed and lived symbiotically inside a host cell.

Photosynthetic (Prokaryote)

A prokaryote that gets energy from sunlight.

Disease-causing (Pathogenic)

A prokaryote that feeds on living things.

Decomposer (Saprotrophic)

A prokaryote that feeds on dead things.

Unicellular

An organism consisting of a single cell.

Multicellular

An organism consisting of many specialized cells working together.

Colony

A group of unicellular organisms living together.

Filamentous

A type of growth where cells form a chain or thread.

mRNA (messenger ribonucleic acid)

A type of RNA that carries genetic information from the DNA in the nucleus to the ribosomes for protein synthesis.

Homeostasis

The maintenance of a stable internal environment.

Glycoproteins

Proteins with attached carbohydrate chains; often found on the cell membrane for recognition.

Receptor Proteins

Proteins in the cell membrane that sense and bind to specific molecules (e.g., hormones, foreign bodies).

Enzymes

Proteins that catalyze (speed up) chemical reactions.

Integral Proteins

Proteins embedded within the phospholipid bilayer of the cell membrane.

Peripheral Proteins

Proteins attached to the surface of the cell membrane.

Micrometre (μm)

One-millionth of a meter (10^-6 m); a unit for measuring cells.

Nanometre (nm)

One-billionth of a meter (10^-9 m); a unit for measuring organelles and molecules.