key words unit 2 cells as living systems bio

cell

The basic structural and functional unit of all living organisms, capable of performing all life processes.

cell wall

A rigid outer layer that provides structure and protection to plant cells, fungi, and some bacteria.

cell/plasma membrane

The semipermeable membrane surrounding the cytoplasm of a cell, regulating the movement of substances in and out.

central vacuole

A large, membrane-bound organelle found in plant cells that stores nutrients, waste products, and helps maintain turgor pressure.

centrioles

Cylindrical structures involved in cell division, found in animal cells, that help organize the mitotic spindle.

chloroplast

An organelle found in plant cells that conducts photosynthesis, converting sunlight into chemical energy.

cilia

Hair-like structures that extend from the surface of some cells, used for movement or sensing the environment.

contractile vacuole

A specialized organelle found in some protozoa and unicellular organisms that helps regulate water balance by expelling excess water.

cytoplasm

The gel-like substance within the cell membrane that contains organelles and is the site of many cellular processes.

cytoplasm

The gel-like fluid that fills the cell, providing a medium for organelles and facilitating biochemical reactions.

cytoskeleton

A network of fibers that provides structural support, shape, and organization to the cell, and is involved in cell movement and division.

endoplasmic reticulum (smooth/rough)

A membranous organelle involved in the synthesis of proteins (rough) and lipids (smooth), and plays a role in detoxification and calcium storage.

eukaryote

An organism whose cells contain a nucleus and membrane-bound organelles, including animals, plants, fungi, and protists.

eyespot

A light-sensitive structure found in some unicellular organisms, such as algae, that helps them detect light and navigate toward it.

flagella

Long, whip-like structures that enable cellular movement in some eukaryotic and prokaryotic cells.

golgi apparatus

A cell organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

lysosome

A membrane-bound organelle that contains digestive enzymes to break down waste materials and cellular debris.

mitochondria

Double-membrane organelles known as the powerhouse of the cell, where ATP is produced through cellular respiration.

multicellular

Organisms composed of many cells that work together to perform functions.

nucleolus

A dense structure within the nucleus responsible for ribosomal RNA synthesis and ribosome assembly.

organ

A group of tissues that work together to perform a specific function in an organism.

organelle

Specialized structures within a cell that perform distinct functions, such as energy production and protein synthesis.

phospholipid bilayer

A double layer of phospholipids that forms the basis of cell membranes, providing a barrier to the passage of ions and molecules.

plasmid

A small, circular piece of DNA found in bacteria that can replicate independently of chromosomal DNA, often used in genetic engineering.

prokaryote

A single-celled organism that lacks a nucleus and membrane-bound organelles, exemplified by bacteria.

pseudopod

A temporary, foot-like extension of a cell used for movement and feeding, commonly found in amoebas and certain white blood cells.

ribosome

A cellular structure made of RNA and proteins that synthesizes proteins by translating messenger RNA.

tissue

A group of similar cells that work together to perform a specific function in an organism.

unicellular

Organisms composed of a single cell that carry out all life processes independently.

vacuoles

Membrane-bound sacs within a cell that store substances such as nutrients, waste products, or water.

vesicles

Small membrane-bound sacs that transport materials within a cell.