Terms in this set (31)
Definition of cell theory. :a theory in biology that includes one or both of the statements that the cell is the fundamental structural and functional unit of living matter and that the organism is composed of autonomous cells with its properties being the sum of those of its cells.
Properties of ALL cells
consist of a nucleus (which contains genetic material), cytoplasm, and organelles, all of which are surrounded by a cell membrane.
a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. Prokaryotes include the bacteria and cyanobacteria.
an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. Eukaryotes include all living organisms other than the eubacteria and archaebacteria.
Properties of prokaryotes
Prokaryotes lack an organized nucleus and other membrane-bound organelles. Prokaryotic DNA is found in a central part of the cell called the nucleoid. The cell wall of a prokaryote acts as an extra layer of protection, helps maintain cell shape, and prevents dehydration.
Properties of eukaryotes
The cells of eukaryotic organisms have several distinguishing characteristics. Above all, eukaryotic cells are defined by the presence of a nucleus surrounded by a complex nuclear membrane. Also, eukaryotic cells are characterized by the presence of membrane-bound organelles in the cytoplasm.
deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
the fundamental and distinctive characteristics or qualities of someone or something, especially when regarded as unchangeable.
Circular DNA is DNA that forms a closed loop and therefore has no free ends that is a complete closed DNA. Examples include: Plasmids - mobile genetic elements. cccDNA - formed by some viruses inside cell nuclei. Circular bacterial chromosomes.
A plasmid is a small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently. ... They are most commonly found in bacteria as small circular, double-stranded DNA molecules; however, plasmids are sometimes present in archaea and eukaryotic organisms.
the material or protoplasm within a living cell, excluding the nucleus
a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
Non-Membrane Bound Organelles. ... Many organelles are also filled with a fluid. These fluid-filled organelles are surrounded by a plasma membrane to separate their insides from the rest of the cytoplasm. These are the so-called membrane bound organelles, such as the lysosomes, Golgi complex, and mitochondria.
the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
Definition of nuclear membrane. :a double membrane enclosing a cell nucleus and having its outer part continuous with the endoplasmic reticulum — called also nuclear envelope; see cell illustration. First Known Use: 1852.
The nuclear pore is a protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm. In eukaryotic cells, the nucleus is separated from the cytoplasm and surrounded by a nuclear envelope. ... These sequence tags are known as nuclear localization signals.
a small dense spherical structure in the nucleus of a cell during interphase.
Rough endoplasmic reticulum
noun, Cell Biology. 1. a network of tubular membranes within the cytoplasm of the cell, occurring either with a smooth surface (smooth endoplasmic reticulum) or studded with ribosomes (rough endoplasmic reticulum) involved in the transport of materials. Origin of endoplasmic reticulum.
Smooth endoplasmic reticulum
The smooth endoplasmic reticulum, or smooth ER, is an organelle found in both animal cells and plant cells. An organelle is a sub-unit within a cell that has a specialized function. The main function of the smooth ER is to make cellular products like hormones and lipids
a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport.
a fluid- or air-filled cavity or sac, in particular.
a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid.
a small cavity or space in tissue, especially in nervous tissue as the result of disease.
an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.
A cell structure that controls which substances can enter or leave the cell.
some substances can pass across them and others cannot
A rigid structure that surrounds the cell membrane and provides support to the cell
An organelle found in plant and algae cells where photosynthesis occurs
Conversion of light energy from the sun into chemical energy.
A green pigment found in the chloroplasts of plants, algae, and some bacteria
powerhouse of the cell
The process by which cells use oxygen to produce energy from food
Ancestors of mitochondria and plastids was prokaryotes thatcame to live in a host cell.