Unit 3: The Cell Flashcards
provides a barrier between the interior and exterior of the cell and it regulates the flow of substances in and out of the cell.
cell membrane
Protective layer for prokaryotes, made of peptidoglycan.
cell wall
In a plant cell. Capture energy from the sun and use that energy to build sugar molecules.
chloroplast
a short, microscopic, hairlike vibrating structure. Occurs in large numbers on the surface of certain cells.
cilia
the fluid that occupies the space inside the cell. the space in which the chemical reactions that enable life take place.
cytoplasm
formed by a series of protein filaments, and is both a scaffold for the cell structure and a framework for many cellular activities, including movement and cell division.
cytoskeleton
a series of sacs and tubes. put together or assemble the proteins and other cellular components.
endoplasmic reticulum (ER)
any of the single-celled or multicellular organisms whose cell contains a distinct, membrane-bound nucleus.
Eukaryotes
External appendage to a prokaryote.
flagella
Where the proteins assembled in the ER are delivered to different parts of the cell, or in multicellular organisms, to different parts of the body.
golgi apparatus
takes fuel in the form of sugar (glucose) and convert it to usable energy ATP.
POWERHOUSE OF THE CELL
mitochondria
Region in a prokaryote, where the DNA molecule is present. Does not have a surrounding membrane.
nucleoid region
Center of the atom. Contains equal number of protons and neutrons.
nucleus
small, simple, single-cell organisms; bacteria are the most prevalent kind. Do not contain a nucleus or any other organelle.
prokaryotes
the molecular machines that use the instructions contained in the DNA to build all the proteins needed by the cell.
ribosome
specialized mainly for storage. Their membranes do not fuse with the membranes of other cellular components.
vacuole
specialized for transport and some other functions. Their membranes can fuse with the plasma membrane, allowing them to empty their contents into the extracellular space. Also may fuse with the membranes of the endoplasmic reticulum and Golgi apparatus, allowing them to empty their contents into those organelles.
vesicle
the fabric of the membrane. The structure causes the membrane to be semipermeable. The hydrophobic core blocks the diffusion of hydrophilic ions and polar molecules. Small hydrophobic molecules and gases, which can dissolve in the membrane’s core, cross it with ease.
phospholipid bilayer
The cell membrane provides a semipermeable barrier between the inside and the outside of the cell. The phospholipid bilayer structure of the membrane allows selected ions and organic molecules to pass through the plasma membrane and regulates the movement of molecular substances.
selectively permeable
moving molecules against their concentration gradient. This is a non- spontaneous process and requires the cell to do work to move the ions “uphill” against the concentration gradient. To do work, the cell must expend energy and actively move (pump) the ions.
active transport
material is engulfed within an infolding of the plasma membrane and then brought into the cell within a cytoplasmic vesicle.
endocytosis
an internal vesicle fuses with the plasma membrane and releases its contents to the outside.
exocytosis
The process of moving impermeable molecules across a membrane (down their concentration gradients) using channels or pores is referred to as _____ ________.
facilitated diffusion
homeostasis
The ability or tendency of organisms and cells to maintain stable internal conditions.
a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
osmosis
both large and small molecules spontaneously move from areas of high concentration to areas of low concentration following random movements, referred to as Brownian motion.
simple diffusion