Cell Organization

Vocabulary

cell line

cultured cells derived from a single cell, thus making all the cells genetically identical

cell membrane

semipermeable membrane (consisting of specialized proteins embedded in a phospholipid bilayer) that surrounds a cell and controls movement of materials into and out of it

central vacuole

large membranous sac that plays an important role in storage and plant cell growth

centriole

structure that coordinates formation of microtubules found in pairs near the nucleus

centrosome

structure in the cytoplasm of animal cells that coordinates the formation of microtubules, allowing cell division to proceed during reproduction

chloroplast

membrane-bound organelle found in plants and some other organisms that captures energy from light and converts it into chemical energy

cytoplasm

combination of cytosol—a jellylike fluid primarily made up of water and dissolved substances that fill the spaces around the internal cell structures—and organelles (excluding the nucleus)

cytosol

aqueous fluid that fills the fluid part of the cytoplasm in the cell

deoxyribonucleic acid (DNA)

organic molecule containing coded instructions for the life processes of an organism; consists of nucleotides bonded together in the form of a double helix

endoplasmic reticulum (ER)

network of membranes that helps process molecules such as proteins and lipids in a cell

fluorescence microscopy

use of specific wavelengths of light to excite dyes or naturally occurring compounds in specimens in order to view them with a microscope

gamete

sex cell of a sexually reproducing organism, with a haploid set of chromosomes

Golgi apparatus

organelle that attaches chemical markers to molecules produced in the endoplasmic reticulum in order to transport the molecules to their places inside or outside a cell

light microscope

microscope that uses light passing through optical lenses to magnify objects

lysosome

organelle that digests bacteria that enters a cell, eliminates toxins, and recycles worn cell materials

magnetosome

membranous pocket within a bacterial cell membrane that contains iron-rich magnetic particles

messenger RNA (mRNA)

molecule made from a DNA template from which a protein is translated; mRNA determines the amino acid sequence in proteins

microscopy

use of a microscope to view objects that are too small to be seen with the eye

mitochondrion (plural, mitochondria)

organelle responsible for generating energy for the cell

model organism

species that is studied because of specific characteristics that make it easy to understand, with an expectation that much of what is learned about the species applies to other species as well

nuclear envelope

double membrane that is semipermeable and surrounds a nucleus

nucleoid

area inside a prokaryotic cell where genetic material (DNA) is found

nucleus

membrane-bound organelle that contains most of the genetic material (DNA). This structure directs a cell's growth, division, and death

ribonucleic acid (RNA)

organic molecule that carries genetic messages out of the nucleus; consists of a single strand of nucleic acids

ribosomal RNA (rRNA)

component of ribosomes that catalyzes peptide bond formation

ribosome

structure composed of RNA and protein that constructs proteins based on the instructions provided by DNA. It may be free-floating in cytoplasm or attached to form rough endoplasmic reticulum.

scanning electron microscope (SEM)

microscope that scans the surface of a sample with a beam of electrons, which are then scattered and reflected to form an image

transfer RNA (tRNA)

molecule that carries each amino acid to the strand of mRNA during translation of protein synthesis

transmission electron microscope (TEM)

microscope that passes a beam of electrons through a sample and onto a sensor