Download Cell Unity Vocabulary

Cell Unit Vocabulary
The Cell Theory
1. All living things are composed of cells.
2. Cells and cell products are the basic units of structure
and function in living things.
3. All cells come from pre-existing cells.
Cytoplasm
 All the living material (organelles and fluid) inside the
cell, except the nucleus.
Organelle
 A small part of the cell, usually enclosed by a membrane
that performs a specialized function.
Cell Membrane
 Selectively permeable structure that encloses the cells’
contents and regulates the passage of materials
between the cell and its environment.
 Also called the plasma membrane.
 Function: Regulates Transport of Substances into /out
of Cell
Nucleus
 In eukaryotic cells, the double membrane-bound
organelle that contains chromosomal DNA, and thus
controls the cell’s activities.
 Function: Controls Cell Activities
Nucleoli
 Irregular rounded structures in the nucleus.
 They are sites of RNA synthesis.
Nuclear Envelope
 The double membrane boundary around the nucleus.
 It contains many pores to allow certain molecules to
pass in and out.
Chromosome
 A rod-like group of genes found in the nucleus of
eukaryotic cells.
 Consists of tightly coiled DNA and proteins.
Chromatin
 A stringy network of DNA and proteins in the nucleus.
 During mitosis and meiosis, it forms rods called
chromosomes.
Endoplasmic Reticulum
 A system of branching membranous channels located in
the cytoplasm, which serves to transport materials
within the cell.
 Rough E.R. contain ribosomes and are a site of protein
synthesis.
 Smooth E.R. have no ribosomes and are a site of lipid
synthesis.
 Function: Transport System
Ribosome
 The protein factory of the cell; they are located on the
endoplasmic reticulum or in the cytoplasm.
 Composed of RNA and protein
 Function: Synthesis of Protein
Mitochondria “The Powerhouse of the Cell”
 Organelles in eukaryotic cells that carry on cellular
respiration.
 Function: Sites of Cellular Respiration
Cristae
 The folding of the inner membrane of the mitochondria.
 ATP formation happens here.
Lysosome
 A membrane-bound organelle that contains digestive
enzymes.
 Function: Intracellular Digestion
Golgi Complex (or Apparatus)
 An organelle consisting of stacks of flattened sacs.
 It modifies and packages substances to be transported
around and out of cells.
 Function: Packages and Secretes Proteins
Vacuole
 Organelle, common in plants, that stores materials such
as food, water, or waste products.
 Function: Storage
Phagocytic Vesicle
 Organelle which forms when the plasma membrane
folds in as the cell engulfs large particles from outside
the cell during phagocytosis.
Microtubules
 Tubular protein structures involved with chromosome
movement during cell division.
 They compose the internal structure of cilia and flagella,
and provide cell shape.
Centrioles
 Animal cell structures made of microtubules; they
organize microtubule assembly of the spindle during
mitosis and meiosis.
Cytoskeleton
 A network of microtubules and other protein filaments
that supports the cell structure and drives cell
movement.
Cilia
 Short hairlike appendages specialized for motion.
 They enable some protista to move.
 They also move material along a cell or tissue.
 Function: Movement
Flagella
 A long whip-like projection that allows certain
protozoans and sperm to move.
 Function: Movement
Cell Wall
 The non-living structure that surrounds the cell
membrane in plants, algae, fungi and some bacteria.
 It protects and supports the cell.
 Function: Protection and Support
Chloroplast
 An organelle found in plants and photosynthetic
protista.
 It contains chlorophyll that absorbs light energy and
converts it to chemical energy.
 Function: Site of Photosynthesis
Pseudopodia
 “False feet” that are extensions of the cytoplasm; they
are used by amoeba for locomotion and food-getting
and by some white blood cells for engulfing foreign
particles in phagocytosis.
Prokaryotic Cell
 A cell that does not have a membrane-bound nucleus or
membrane-bound organelles; monerans are comprised
of this kind of cell.
Eukaryotic Cell
 A cell that contains a membrane-bound nucleus and
membrane bound organelles; all kingdoms except
monera contain this type of cell.
Diffusion
 The movement of a substance from areas of higher
concentration to areas of lower concentration of the
substance.
Osmosis
 The diffusion of water molecules across a selectively
permeable membrane (as in a cell membrane).
Selectively Permeable
 A property of biological membranes that allows some
substances (but not others) to pass through.
Active Transport
 The movement of a substance across a membrane
against its concentration gradient; requires an input of
cellular energy, usually in the form of ATP.
Endocytosis
 The uptake of materials by the cell.
 Examples: phagocytosis, pinocytosis
Exocytosis
 The release of materials from the cell into the
environment when vesicles fuse with the cell
membrane.
Anton Van Leeuwenhoek
 Dutch biologist given credit for inventing the first
microscope (1600’s).
Robert Hooke
 British scientist who used the microscope to look at
cork and called the chambers “cells” (1600’s).
Matthias Schleiden
 German botanist who stated that all plants are made of
cells (1838).
 Credited with Schwann for the Cell Theory.
Theodor Schwann
 Discovered that all animals are made of cells (1839).
 Credited with Scheiden for the Cell Theory.
Rudolf Virchow
 A German physician who stated that all cells come from
pre-existing cells (1855).