Cell Structure

Cell wall

rigid cell covering comprised of various molecules that protects the cell, provides structural support, and gives shape to the cell

Central vacuole

large plant cell organelle that regulates the cell’s storage compartment, holds water, and plays a significant role in cell growth as the site of macromolecule degradation

Centrosome

region in animal cells made of two centrioles that serves as an organizing center for microtubules

Chlorophyll

green pigment that captures the light energy that drives the light reactions of photosynthesis

Centriole

Complex assembly of microtubules that occurs in pairs

Chloroplast

plant cell organelle that carries out photosynthesis

Chromatin

protein-DNA complex that serves as the chromosomes' building material

chromosome

structure within the nucleus that comprises chromatin that contains DNA, the hereditary material

cilium

(plural = cilia) short, hair-like structure that extends from the plasma membrane in large numbers and functions to move an entire cell or move substances along the cell's outer surface

cytoplasm

entire region between the plasma membrane and the nuclear envelope, consisting of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals. Semi fluid matrix containing nucleus and other organelles

cytoskeleton

Protein fiber network that collectively maintains the cell's shape, secures some organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently. Vital for maintaining organisation and function of cells.

cytosol

the cytoplasm's gel-like material in which cell structures are suspended

endomembrane system

group of organelles and membranes in eukaryotic cells that work together modifying, packaging, and transporting lipids and proteins

endoplasmic reticulum (ER)

series of interconnected membranous structures within eukaryotic cells that collectively modify proteins and synthesize lipids

eukaryotic cell

cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs

extracellular matrix

material secreted from animal or fungal cells that provides mechanical protection and anchoring for the cells in the tissue

flagellum

(plural = flagella) long, hair-like structure that extends from the plasma membrane and moves the cell

Nuclear pore

Opening embedded with proteins that regulates passage into and out of the nucleus

Golgi apparatus

eukaryotic organelle comprised of a series of stacked membranes that sorts, tags, and packages lipids and proteins for distribution. Collects, packages, and distributes molecules manufactured in the cell

intermediate filament

cytoskeletal component, comprised of several fibrous protein intertwined strands, that bears tension, supports cell-cell junctions, and anchors cells to extracellular structures. Intertwined protein fibers that provide support and strength

lysosome

organelle in an animal cell that functions as the cell’s digestive component; it breaks down proteins, polysaccharides, lipids, nucleic acids. Digests worn out organelles

microfilament /Actin filament

the cytoskeleton system's narrowest element; it provides rigidity and shape to the cell and enables cellular movements. Twisted protein fibers responsible for cell movement

microtubule

the cytoskeleton system's widest element; it helps the cell resist compression, provides a track along which vesicles move through the cell, pulls replicated chromosomes to opposite ends of a dividing cell, and is the structural element of centrioles, flagella, and cilia. Tube of protein molecules present in cytoplasm, cilia, centrioles, and flagella

mitochondria

(singular = mitochondrion) cellular organelles responsible for carrying out cellular respiration, resulting in producing ATP, the cell’s main energy-carrying molecule

nuclear envelope

double-membrane structure that constitutes the nucleus' outermost portion. Helps maintain shape of nucleus and organises chromatin within it.

nucleoid

central part of a prokaryotic cell's central part where the chromosome is located

nucleolus

darkly staining body within the nucleus that plays important role in producing and assembling ribosomes.

nucleoplasm

semi-solid fluid inside the nucleus that contains the chromatin and nucleolus

nucleus

cell organelle that houses the cell’s DNA and directs ribosome and protein synthesis

organelle

compartment or sac within a cell

peroxisome

Vesicle containing enzymes that detoxify potentially harmful molecules

plasma membrane

phospholipid bilayer with embedded (integral) or attached (peripheral) proteins, and separates the cell's internal content from its surrounding environment. Selectively permeable, regulates what enters and exits the cell

Secretory vesicle

Vesicle fusing with plasma membrane, releasing materials to be secreted from the cell

prokaryote

unicellular organism that lacks a nucleus or any other membrane-bound organelle

ribosome

cellular structure that carries out protein synthesis

rough endoplasmic reticulum (RER)

region of the endoplasmic reticulum that is studded with ribosomes and carries out protein synthesis

smooth endoplasmic reticulum (SER)

region of the endoplasmic reticulum that has few or no ribosomes on its cytoplasmic. Aids in the manufacture of carboydrates and lipids

unified cell theory

a biological concept that states that one or more cells comprise all organisms; the cell is the basic unit of life; and new cells arise from existing cells

vacuole

membrane-bound sac, somewhat larger than a vesicle, which functions in cellular storage and transport

vesicle

small, membrane-bound sac that functions in cellular storage and transport; its membrane is capable of fusing with the plasma membrane and the membranes of the endoplasmic reticulum and Golgi apparatus