Cell: The Building Block of Life Vocabulary

Vocabulary flashcards covering the key terms, structures, tools, and processes related to cell biology.

Thermophiles

Heat-loving unicellular bacteria that live in high-temperature environments, such as the hot springs of Puga Valley, Ladakh.

Puga Valley, Ladakh

A location with hot springs having high temperatures similar to early Earth $3.5\text{ billion years ago}$.

Calcium Carbonate Deposits

Mineral deposits around hot springs that may have protected early organic molecules and helped form the first cell membranes.

Cell

The basic structural and functional unit of all living organisms.

Unicellular Organism

An organism consisting of a single cell, such as bacteria, yeast, or amoeba.

Multicellular Organism

An organism consisting of many cells, such as plants and animals, where cells form tissues, organs, and organ systems.

Human Eye Resolution Limit

The minimum distance limit of resolution for the naked human eye, which is $0.1\,\text{mm}$.

Robert Hooke

The scientist who first observed cells in 1665 using a microscope.

Light Microscope

A microscope that uses visible light to magnify objects from $10\times$ to $40\times$.

Electron Microscope

A microscope that uses electron beams to reveal structures at the nanometre scale ($1\,\text{nm} = 0.000001\,\text{mm}$).

Resolution

A key feature of microscopes referring to the clarity of an image.

Contrast

A key feature of microscopes referring to the brightness difference between parts of an image.

Magnification

A key feature of microscopes referring to the increase in the visual size of an object.

Cell Membrane (Plasma Membrane)

A selectively permeable boundary present in all cells that regulates what enters and exits.

Fluid Mosaic Model

A model describing the cell membrane as a lipid bilayer with embedded proteins, where molecules move sideways (fluid) and are arranged like tiles (mosaic).

Diffusion

The movement of particles from a higher concentration to a lower concentration without requiring a membrane.

Osmosis

The diffusion of water through a selectively permeable membrane from a dilute solution to a concentrated solution.

Isotonic Solution

A solution concentration that results in no net change in cell size.

Hypotonic Solution

A solution that causes water to enter the cell, making the cell swell.

Hypertonic Solution

A solution that causes water to leave the cell, making the cell shrink.

Cell Wall

A rigid structure made of cellulose located outside the cell membrane in plant cells that provides support and shape.

Plasmolysis

The phenomenon occurring when plant cells lose water and their cell membrane pulls away from the cell wall.

Cytoplasm

The jelly-like substance in a cell containing various organelles performing specific functions.

Nucleus

The control center of the cell surrounded by a double membrane with pores, containing the nucleolus and chromosomes made of DNA and proteins (genes).

Prokaryotic Cells

Cells lacking a well-defined nucleus (DNA located in a nucleoid) and membrane-bound organelles, ranging in size from $1\text{--}10\,\mu\text{m}$ (e.g., bacteria).

Eukaryotic Cells

Cells with a well-defined nucleus enclosed by a membrane and membrane-bound organelles, ranging in size from $10\text{--}100\,\mu\text{m}$ (e.g., plant and animal cells).

Ribosomes

Organelles that serve as the site of protein synthesis, existing freely in cytoplasm or on the endoplasmic reticulum.

Endoplasmic Reticulum (ER)

An intracellular network responsible for cellular synthesis and transport.

Rough ER (RER)

Part of the endoplasmic reticulum studded with ribosomes that synthesizes proteins.

Smooth ER (SER)

Part of the endoplasmic reticulum that lacks ribosomes and synthesizes lipids and hormones.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids into vesicles for transport.

Lysosomes

Organelles containing digestive enzymes that break down waste products and damaged cell parts so their components can be reused.

Mitochondria

Double-membraned organelles with inner folds called cristae that act as the site of cellular respiration producing ATP.

ATP

The main energy currency of the cell produced during cellular respiration in mitochondria.

Chloroplasts

Plant plastids containing chlorophyll used for photosynthesis.

Chromoplasts

Plant plastids containing pigments responsible for color in flowers and fruits.

Leucoplasts

Colorless plant plastids that store food materials such as starch and oils.

Large Central Vacuole

A prominent vacuole in plant cells that stores water and maintains turgor pressure.