Cell Flashcards
Considered the basic unit of living organism
Cells
What are the levels of organization
Chemicals
Organelles
Cells
Tissues
Organs
Organ system
Organism
are microscopic units composed of a bubble of fatty material filled with a water-based mixture of molecules and tiny particles.
Cells
Parts of the cell are called ___ (meaning “small organs”).
Organelles
The outer boundary of the cell is the _____. It is composed of a double layer (or bilayer) of phospholipid molecules imbedded with other molecules.
Plasma membrane
Each phospholipid molecule has a polar, ____ (“water loving”) head made up of ____, and a nonpolar, ____ (“water fearing”) tail made up of two ___. Imbedded in the membrane are integral proteins, which may have additional protein molecules called peripheral proteins attached to them on one side of the membrane or the other.
hydrophilic - phosphate & glycerol
hydrophobic - fatty acid chains
The ___ has many functions, most involving transport and communication between the inside and outside of the cell
plasma membrane
The material within the plasma membrane is the ____ (literally, “cell stuff”) and includes both the organelles and the liquid, or cytosol, surrounding the organelles.
Cytoplasm
____ are tiny bodies that serve as a site for protein synthesis. Some ___ are found on the outer surface of the ER, and some are found scattered elsewhere within the cell.
Ribosomes
The ____, appears as a stack of fattened sacs. The apparatus receives material from the ER, processes it, and then packages it in tiny vesicles (bubbles) for possible export from the cell.
Golgi apparatus, or Golgi body
are tiny bodies similar to bacteria that serve as sites for adenosine triphosphate (ATP) synthesis (energy conversion). ___ have an outer membrane, forming a round or oblong cap-sule, and a folded inner membrane. The folds of the inner membrane are called ___.
Mitochondria (singular mitochondrion)
Cristae
are vesicles containing digestive enzymes that digest foreign particles and worn or no longer needed cell parts. In addition, ____ play a role in repairing the plasma membrane.
Lysosomes
are very tiny, hollow beams that form part of the supporting cell skeleton, or cytoskeleton. They also form parts of other cell organelles (e.g., flagella, cilia, centrioles, spindle fibers). Other components of the cytoskeleton include microfilaments and intermediate filaments.
Microtubules
The ___ organizing center, is a dense area of cell fluid near the nucleus. The ____ contains a pair of centrioles, cylinders formed by parallel microtubules.
centrosome, or microtubule
A network of microtubules called ___ extends from the centrosome during cell division. It distribute DNA equally to the resulting daughter cells.
Spindle fibers
are tiny, finger-like projections of the cell that increase the membrane’s surface area for more efficient absorption.
Microvilli
are numerous short, hair-like organelles that propel material along a cell’s surface.
Cilia
are single, long, hair-like organelles found in sperm cells to propel them through the female reproductive tract toward the egg.
Flagella
are membranous bubbles that may be formed by the Golgi apparatus or by the pinching inward of the cell membrane to engulf external substances.
Vesicles
An ____ is an instrument that uses a beam of electrons, rather than a beam of light, to form the image of a tiny specimen.
electron microscope
____ send an electron beam through the specimen, similar to the manner in which a light microscope sends a light beam through a specimen. However, the magnifying power and resolution are much greater in the electron microscope.
Transmission electron microscopes
___ is the ability to distinguish detail.
Resolution
reflect an electron beam off the specimen. The shadows produced by a ___ beam lend a three-dimensional effect.
Scanning electron microscopes
A TEM is a ____ (photograph taken with a transmission electron microscope).
transmission electron micrograph
What are the membranous organelles
Nucleus
ER
Mitochondrion
Golgi Apparatus
Lysosome
Plasma membrane
What are the non-membranous organelles
Ribosome
Centriole
Nucleolus
processes are those that require no metabolic energy from the cell but rely solely on the physical properties of the substances themselves.
Passive transport
processes require energy expenditure by the cell to move substances whose physical properties prevent their independent motion.
Active transport
Naturally occurring ____ drives passive transport processes. Discovered by Scottish scientist Robert Brown, ____ is the constant movement of all particles of matter.
brownian motion
can be defined as the net movement of particles from an area of high concentration to an area of low concentration.
Diffusion
Some particles move down such a ___ when they are allowed to cross a cell membrane.
concentration gradient
If the particles transported are water molecules and there is at least one impermeant solute present (i.e., a solute that cannot cross the membrane freely), we see a transport process called ___.
osmosis
TRUE or FALSE
The side of the membrane with a higher impermeant solute concentration has a lower osmotic pressure.
False.
Higher osmotic pressure
can be further described as equal to the force moving water into a solution by osmosis.
Osmotic pressure
____ is a comparative term that refers to a solution that has the same osmotic pressure as the cell solution
Isosmotic
is one with a lower osmotic pressure (i.e., a higher water concentration). Thus the outside solution is ____ to the solution inside the cell model.
hypo-osmotic solution
a solution with a higher osmotic pressure (or lower water concentration).
hyperosmotic solution
When the osmotic pressure of two solutions on either side of a membrane is known, the ___ can be predicted.
net direction of osmosis
The movement of particles across a membrane from an area of high pressure to an area of low pressure (down a hydrostatic pressure gradient) is called ____.
filtration
