Cell: The Building Block of Life Flashcards

This set of vocabulary flashcards covers the fundamental concepts of cell biology, including cell structure, organelles, microscopy, and types of cell division based on the provided lecture notes.

Thermophiles

Heat-loving unicellular bacteria, such as those found in the hot springs of Puga Valley, that thrive at temperatures near the boiling point of water.

Tissue

A group of similar cells performing similar functions.

Limit of resolution

The ability of the human eye to see two very close objects as separate and distinct, which is approximately $0.1\,mm$ at a distance of $25\,cm$.

Robert Hooke

The scientist who first observed small box-like compartments in cork in 1665 and named them ‘cells’.

Total magnification

The final magnifying power of a microscope calculated by multiplying the magnifying power of the eyepiece by that of the objective lens.

Resolution

A feature of a microscope that serves as a measure of the clarity of the image.

Electron microscope

A powerful magnifying instrument that uses a beam of electrons instead of light to reveal fine details of cell structures at the nanometre scale.

Cell membrane

A thin, selectively permeable boundary made of lipids and proteins that protects cell contents and defines the individuality of a cell.

Osmosis

The movement of water through a selectively permeable membrane from an area with more water (dilute solution) to an area with less water (concentrated solution).

Diffusion

The net movement of particles from a higher concentration to a lower concentration, occurring even without a membrane.

Isotonic solution

A solution where the solute concentration of the extracellular medium is equal to the solute concentration of the intracellular medium.

Hypotonic solution

A solution where the solute concentration of the extracellular medium is less than the solute concentration of the intracellular medium, causing a cell to swell.

Hypertonic solution

A solution where the solute concentration of the extracellular medium is greater than the solute concentration of the intracellular medium, causing a cell to shrink.

Fluid-mosaic model

A model describing the cell membrane as a lipid bilayer with embedded proteins where molecules can move sideways, flip, and rotate.

Cell wall

An additional rigid, permeable layer outside the cell membrane found in plants, fungi, and bacteria for structural support and protection.

Cellulose

A type of carbohydrate formed by linked glucose units that primarily makes up the plant cell wall.

Prokaryotic cells

Cells that lack a well-defined nucleus and membrane-bound organelles; their genetic material is present in a region called the nucleoid.

Eukaryotic cells

Cells that contain a well-defined nucleus and several membrane-bound organelles, typically ranging from $10$ to $100\,\mu m$ in diameter.

Cytoskeleton

A network of fine fibres in eukaryotic cells that provides structural support, maintains cell shape, and enables movement.

Nucleolus

A dense round body within the nucleus where the synthesis of ribosomal subunits takes place.

Chromosomes

Rod-shaped structures composed of DNA and proteins that contain genetic information for inheritance, visible only when a cell is about to divide.

Genes

The functional segments of DNA that contain genetic information.

Ribosomes

Tiny structures located freely in the cytoplasm or attached to the endoplasmic reticulum that serve as the sites of protein synthesis.

Rough Endoplasmic Reticulum (RER)

A type of ER with ribosomes attached to its surface, mainly involved in protein synthesis and secretion.

Golgi apparatus

Stacks of flattened, sac-like structures that modify, sort, and package proteins and lipids into vesicles for transport.

Lysosomes

Single membrane-bound sacs filled with enzymes that break down unwanted materials and damaged cell parts to keep the cell clean.

Mitochondria

The 'powerhouses of the cell' where glucose is broken down to release energy in the form of ATP during cellular respiration.

Adenosine Triphosphate (ATP)

The molecule that acts as the energy currency for most cellular activities.

Plastids

Special organelles used by plants for food synthesis and storage, including chloroplasts, chromoplasts, and leucoplasts.

Mitosis

The most common type of cell division that produces two genetically identical daughter cells for growth, repair, and maintenance.