A relatively rigid structure that encloses cells of plants, fungi, many protists, and most prokaryotes, and which gives these cells their shape and limits their expansion in hypotonic media.
plasma membrane�lined channels of adjacent plant cells that allow water, ions, small molecules, hormones, and even some RNA and protein molecules to move between connected cells cell wall. This allows energy (sugars) to be shared and hormones to travel
The membrane that surrounds the cell, regulating the entry and exit of molecules and ions. Every cell has a plasma membrane.
The fluid portion of the cytoplasm, excluding organelles and other solids.
A class of plant cell organelles that includes the chloroplast, which houses biochemical pathways for photosynthesis.
a minute cytoplasmic body from which a plastid is formed
An organelle bounded by a double membrane containing the enzymes and pigmentst hat perform photosynthesis. Chloroplasts occur only in eukaryotes.
The fluid contents of an organelle such as a chloroplast or mitochondrion.
A flattened sac within a chloroplast. Thylakoid membranes contain all of the chlorophyll in a plant, in addition to the electron carriers of photophosphorylation. Thylakoids stack to form grana
one of the lamellar stacks of chlorophyll-containing material in plant chloroplasts
Any of several green pigments associated with chloroplasts or with certain bacterial membranes; responsible for trapping light energy for photosynthesis.
A yellow, orange, or red lipid pigment commonly found as an accessory pigment in photosynthesis; also found in fungi.
any of several orange or red crystalline hydrocarbon pigments (as C40H56) that occur in the chromoplasts of plants and in the fatty tissues of plant-eating animals and are convertible to vitamin A
any of several neutral yellow to orange carotenoid pigments that are oxygen derivatives of carotenes; especially : lutein
an orange xanthophyll C40H56O2 occurring in plants usually with carotenes and chlorophylls and in animal fat, egg yolk, and the corpus luteum
a colored plastid usually containing red or yellow pigment (as carotene)
A colorless plastid in the cytoplasm of plant cells around which starch collects
An organelle in eukaryotic cells that contains the enzymes of the citric acid cycle, the respiratory chain, and oxidative phosphorylation
One of the inward projections or folds of the inner membrane of a mitochondrion.
The Golgi apparatus in plant cells.
endoplasmic reticulum (ER)
A system of membranous tubes and flattened sacs found in the cytoplasm of eukaryotes. Exists in two forms: rough ER, studded with ribosomes; and smooth ER, lacking ribosomes.
A small particle in the cell that is the site of protein synthesis
An organelle that houses reactions in which toxic peroxides are formed and then converted to water
An organelle found in plants, in which stored lipids are converted to carbohydrates
The network of microtubules and microfilaments that gives a eukaryotic cell its shape and its capacity to arrange its organelles and to move.
Tubular structures found in centrioles, spindle apparatus, cilia, flagella, and cytoskeleton of eukaryotic cells. These tubules play roles in the motion and maintenance of shape of eukaryotic cells.
In eukaryotic cells, a fibrous structure made up of actin monomers. Microfilaments play roles in the cytoskeleton, in cell movement, and in muscle contraction.
Components of the cytoskeleton whose diameters fall between those of the larger microtubules and those of the smaller microfilaments.
Membrane-enclosed organelle in plant cells that can function for storage, water concentration for turgor, or hydrolysis of stored macromolecules.
The membrane of the plant central vacuole.
Any of various water-soluble pigments that impart to flowers and other plant parts colors ranging from violet and blue to most shades of red.
(1) In cells, the centrally located compartment of eukaryotic cells that is bounded by a double membrane and contains the chromosomes. (2) In the brain, an identifiable group of neurons that share common characteristics or functions.
The double-layered membrane enclosing the nucleus of a eukaryotic cell. The nuclear envelope has pores that allow the passage of materials into and out of the nucleus. Also called nuclear membrane.
The protoplasm of a cell nucleus. Also called karyoplasm.
The colorless, liquid component of the cell nucleus
A small, generally spherical body found within the nucleus of eukaryotic cells. The site of synthesis of ribosomal RNA.
The nucleic acid�protein complex that makes up eukaryotic chromosomes.