A2.2 Cell Structure

Cell Theory

The scientific theory that states all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells.

Microscope

An instrument used to view objects that are too small to be seen by the naked eye.

Magnification

The process of enlarging the appearance of an object.

Resolution

The ability of a microscope to distinguish two close objects as separate.

Eukaryote

An organism whose cells contain a nucleus and other organelles enclosed within membranes.

Prokaryote

A unicellular organism that lacks a membrane-bound nucleus.

Ribosome

A cellular structure responsible for protein synthesis.

Cytoplasm

The jelly-like substance within a cell that contains organelles.

Plasma Membrane

The membrane surrounding the cell that regulates what enters and exits.

Mitochondrion

An organelle that produces ATP through aerobic respiration.

Chloroplast

An organelle found in plant cells that conducts photosynthesis.

Vacuole

A storage organelle in cells that can hold various substances.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins for secretion.

Endoplasmic Reticulum (ER)

An organelle involved in protein and lipid synthesis, consisting of rough (with ribosomes) and smooth (without ribosomes) types.

Nucleus

The organelle that contains the cell's genetic material (DNA) and controls cellular activities.

Electron Microscope

A type of microscope that uses electrons to illuminate and magnify the object.

Deductive Reasoning

A logical process where conclusions are derived from general principles or theories.

Homeostasis

The maintenance of stable internal conditions in an organism.

Cell Differentiation

The process by which a cell becomes specialized for a specific function.

Endosymbiotic Theory

The theory that explains the origin of eukaryotic cells from prokaryotic cells through symbiotic relationships.

Multicellular Organisms

Organisms that consist of more than one cell and are capable of cell specialization.

Atypical Cell Structure

Cells that deviate from the typical structure found in most eukaryotic cells, such as multinucleate cells.

Microvilli

Finger-like projections on epithelial cells that increase surface area for absorption.

Fluid Mosaic Model

The model that describes the structure of cell membranes, illustrating how various components move and interact.