Cell Structure, Cell Theory, and Microscope Magnification Flashcards

Vocabulary flashcards covering cell theory, prokaryotic and eukaryotic organelle structures and functions, and microscope magnification calculations.

Cell Theory

A foundational biological principle consisting of three tenets: I. All living things are composed of cells, II. The cell is the basic unit of life, and III. Cells come from preexisting cells.

Scientific Theory

A well-substantiated explanation of an aspect of the natural world that is acquired through the scientific method and repeatedly confirmed through observation and experimentation.

Prokaryotic Cell

A simple, smaller cell (\approx 0.2 - 10\,̦m) that lacks a nucleus and membrane-bound organelles, contains circular naked DNA in the cytoplasm, and evolved around $3.8$ billion years ago.

Eukaryotic Cell

A larger, complex cell (\approx 10 - 100\,̦m) containing a nucleus, linear DNA wrapped around histone proteins, and membrane-bound organelles.

Nucleoid

The area within the cytoplasm of a prokaryotic cell that contains its circular DNA without being enclosed by a nuclear membrane.

Capsule

An outer protective layer found in some prokaryotic cells that prevents dehydration and aids in adhering to surfaces.

Pili

Hair-like surface extensions on some prokaryotes that allow the cell to attach to surfaces, swap DNA with other cells, or harpoon environmental DNA.

Nucleus

A double-membrane organelle in eukaryotic cells that contains DNA instructions for making proteins and houses the nucleolus.

Nucleolus

A structure located inside the eukaryotic cell nucleus responsible for producing ribosomes.

Ribosomes

Cellular structures present in all cells that build protein (polypeptide) chains from two subunits.

Free Ribosomes

Ribosomes floating unattached in the cytosol that synthesize proteins for use within the cell.

Bound Ribosomes

Ribosomes attached to the rough endoplasmic reticulum that synthesize proteins meant to be exported out of the cell or embedded in membranes.

Rough Endoplasmic Reticulum

A series of flattened membranes studded with bound ribosomes that serves as a transport network for proteins in eukaryotic cells.

Smooth Endoplasmic Reticulum

A network of flattened membranes lacking ribosomes that synthesizes lipids and participates in cell membrane repair.

Golgi Apparatus

An organelle that receives, modifies, sorts, concentrates, and packages proteins into vesicles for internal transport or secretion.

Vesicles

Tiny membrane-bound sacs that store and transport molecules within the cell or secrete materials out of the cell.

Lysosome

A single-membrane spherical organelle filled with enzymes that digest, degrade, and recycle large molecules and old or damaged cell components.

Mitochondria

Double-membrane bound organelles that generate cellular energy in the form of ATP via cell respiration.

Chloroplasts

Plant cell organelles containing chlorophyll that capture light energy, water, and carbon dioxide to produce glucose via photosynthesis.

Cell Wall

A rigid outer boundary present in plant cells (made of cellulose) and prokaryotes (often peptidoglycan) that provides structure and withstands turgor pressure.

Central Vacuole

A large central storage organelle in plant cells that occupies $30\% - 90\%$ of the cell volume, primarily storing water.

Cilia and Flagella

Cell surface extensions that aid in movement; cilia are short and numerous with coordinated beating, while flagella are longer and move independently in a propeller-like fashion.

Cytosol

The gel-like liquid part of cytoplasm made of water and dissolved solutes including salts, fatty acids, sugars, amino acids, and enzymes.

Cell Membrane

A phospholipid bilayer barrier present in all cells that regulates what enters and exits the cell according to the fluid mosaic model.

Magnification Formula

$$\text{Magnification} = \frac{\text{size of image}}{\text{actual size of specimen}}$$

Actual Size Formula

$$\text{Actual size of specimen} = \frac{\text{size of image}}{\text{magnification}}$$

Image Size Formula

$$\text{Image size} = \text{Magnification} \times \text{Actual Size}$$

Millimeter to Micrometer Conversion

$1\,mm = 1000\,\mu m$ and $1\,\mu m = 0.001\,mm$