2.3 Flashcards
Cytoplasm
The viscous, semiliquid substance contained in the interior of a cell
Nucleus
A structure in the central region
of a cell, containing the chromosomes
Chromosome
A strand of DNA, with
associated proteins, found in the nucleus;
carries genetic information
DNA
A long, complex macromolecule consisting of two interconnected helical strands; along
with associated proteins, strands of DNA
constitute the chromosomes.
Gene
The functional unit of the chromosome, which directs synthesis of one or more proteins
Enzyme
A molecule that controls a chemical reaction, combining two substances or
breaking a substance into two parts.
Mitochondria
Organelles that are responsible for extracting energy from nutrients
ATP
A molecule of prime importance
to cellular energy metabolism; its
breakdown liberates energy.
Glia
The supporting cells of the central nervous system
Astrocyte
A glial cell that provides support for neurons of the central nervous system, provides nutrients and other substances, and regulates the chemical composition of the extracellular fluid.
Phagocytosis
The process by which cells
engulf and digest other cells or debris
caused by cellular degeneration
Oligodendrocyte
A type of glial cell in the CNS that forms myelin sheaths
node of Ranvier
A naked
portion of a myelinated axon between
adjacent oligodendroglia or Schwann cells.
Microglia
The smallest of glial cells; they
act as phagocytes and protect the brain
from invading microorganisms
Schwann cell
A cell in the peripheral
nervous system that is wrapped around a
myelinated axon, providing one segment
of its myelin sheath
