Anatomy of the Cell: Structure, Function, and Organization

Vocabulary flashcards covering cell anatomy, eukaryotic and prokaryotic cell structures, organelle functions, energy processes, and plant cell wall physiology.

Cell

The fundamental unit of life that forms all tissues, organs, and living organisms.

Cell Theory

The core biological doctrine stating that all living things are made of cells, the cell is the basic unit of life, and all cells come from pre-existing cells.

Prokaryotic Cell

The first form of life, characterized by a simple structure that lacks a membrane-enclosed nucleus.

Eukaryotic Cell

A complex cell type containing a membrane-bound nucleus and membrane-bound organelles, present in plant and animal organisms.

Nuclear Envelope

A double membrane enclosing the cell nucleus equipped with protein-lined pores to regulate the passage of materials.

Chromatin

The complex of DNA and associated proteins located inside the eukaryotic nucleus.

Nucleolus

A condensed region within the nucleus responsible for the formation of ribosomes.

Peroxisome

An organelle that houses oxidative metabolism within the eukaryotic cell.

Rough Endoplasmic Reticulum

An organelle network studded with ribosomes that produces secretory and membrane proteins.

Smooth Endoplasmic Reticulum

A region of the endoplasmic reticulum responsible for synthesizing lipids.

Microtubules

Cytoskeletal elements that maintain cell shape and form the mitotic spindle during nuclear division.

Centrosome

The main microtubule-organizing center located within animal cells.

Intermediate Filaments

Fibrous cytoskeletal proteins that hold organelles securely in place within the cell.

Microfilaments

Fibrous cytoskeletal proteins that form the cellular cortex.

Lysosome

An organelle in animal cells that digests food and breaks down waste materials.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins received from the endoplasmic reticulum.

Mitochondria

The organelle known as the powerhouse of the cell that generates cellular energy.

Adenosine Triphosphate (ATP)

The primary energy transfer molecule composed of an adenine nitrogenous base, a 5-carbon ribose sugar, and a triphosphate chain linked by phosphoanhydride bonds.

Chloroplast

A plant cell organelle bounded by double membranes and containing thylakoids and stroma, which functions as the site of photosynthesis.

Light Reactions

Photosynthetic reactions occurring in the thylakoid membrane that convert light energy and $H_2O$ into ATP, NADPH, and $O_2$.

Calvin Cycle

Photosynthetic reactions occurring in the stroma that convert $CO_2$, ATP, and NADPH into sugar.

Endosymbiotic Theory

The theory stating that early eukaryotes evolved by engulfing aerobic bacteria (which became mitochondria) and photosynthetic bacteria (which became chloroplasts).

Middle Lamella

An outer adhesive layer containing pectin that glues adjacent plant cell walls together.

Primary Cell Wall

A structural plant layer composed of cellulose microfibrils, hemicellulose, and pectin.

Cellulose

A complex carbohydrate polysaccharide composed of repeating glucose monomer units forming cell wall microfibrils.

Plasmodesmata

Channels passing through plant cell walls that allow direct transport and communication between neighboring plant cells.

Primary Pit Field

A distinct cluster of plasmodesmata situated on a primary cell wall.

Central Vacuole

A large plant organelle filled with cell sap that regulates cellular turgor pressure.

Tonoplast

The selective membrane that surrounds the central vacuole in a plant cell.

Cell Sap

The fluid solution enclosed within the tonoplast of a central vacuole.

Turgid

The swollen and firm condition of a plant cell when filled with water, pushing high pressure against the cell wall.

Flaccid

The limp condition of a plant cell caused by water loss from the vacuole.