PRELIMS 30% Flashcards
are the basic functional and structural units of living
organisms.
CELL
Has a true nucleus
surrounded by
nuclear membrane
basic cell type
EUKARYOTIC CELL
- Lacks a nuclear envelope
- Nuclear substance is mixed
or in direct contact with
the rest of the protoplasm.
basic cell type
prokaryotic cell
what cells can be found in the cytoplasm?
4 toh
o Organelles
o Inclusions
o Cytoskeletons
o Cytoplasmic matrix
what are thecells located in the NUCLEUS
o Chromatin
o Nucleolus
o Nuclear envelope
o Nucleoplasm
A CELL WHICH
➜ Modified fluid-mosaic model
➜ Membrane
* Lipids
o Phospholipids
o Cholesterols
* Proteins
* Carbohydrates
➜ Amphipathic lipid
bilayer
PLASMA MEMBRANE
- Gives shape to the cell.
- Regulates the passage of ions and macromolecules
in and out of the cell, selective permeability - It contains devices for cell attachment.
- Involved in cell-to-cell communication.
PLASMA MEMBRANE
- Has antigenic molecules that are the basis of
recognition and tissue specificity. - Involved in ion pumps for regulating the internal
environment. - Contains receptors for hormones.
- Generates messenger molecules that activate the
cell’s physiological responses to stimuli
PLASMA MEMBRANE
Type of JUNCTIONAL COMPLEXES which function:
Couples intermediate
filaments to plasma
membrane at regions
of cell-to-cell adhesion
macula adherens
Couples actin
cytoskeleton to plasma
membrane at regions
of cell-to-cell adhesion
(type of juncrional complexes)
zonula adherens
Seals adjacent cells
together to inhibit
passage of molecules
between them (control
of permeability)
(type of junctional complexes)
zonula occludens
Creates a conduit
between two adjacent
cells for passage of
small ions and
informational
macromolecules
nexus/gap junction
- Finger-like cytoplasmic projections on apical surface
of most epithelial cells - Greatly increase the free cell surface area
microvili
These are Examplesof what cell
o Striated borders – epithelium of the GIT
o Brush borders – epithelium of PCT of the
kidneys
microvili
- Extremely long processes that extend from the apical
surface of the cell - Facilitate absorption
Stereocilia
example of stereocilia
epididymis
- Motile cytoplasmic processes
- Move fluid and particles
Cilia
respiratory passages are example of what cell
cilia
➜ Interconnected membrane-limited flattened sacs
called cisternae (also found in SER)
➜ Studded particles called ribosomes
➜ Site of protein synthesis and modification of newly
synthesized proteins (protein synthesis)
rough-surfaced endoplasmic reticulum
➜ Cisternae appear as interconnected channels of
variable shapes and sizes
➜ Without attached ribosomes
➜ Involved in lipid and steroid synthesis
smooth-surfaced endoplasmic reticulum
➜ Series of stacked, flattened, membrane-limited sacs
or cisternae and tubular extensions
➜ Often adjacent to one side of the cell
➜ Posttranslational modifying, sorting, and packaging
proteins and lipids for intercellular and extracellular
transport.
golgi apparatus
➜ Small organelles that contain digestive enzymes
➜ Generally spherical membrane-enclosed vesicles
➜ Degradation of macromolecules to micromolecules
➜ Sites of intracellular digestion
➜ Particularly numerous in cells active in various types of
endocytosis.
Lysosomes
➜ Two-membrane system
➜ Outer membrane and inner membrane arranged in
numerous folds called cristae
➜ In steroid-producing cells, inner membrane is in
tubular cristae
➜ Provide most of the energy to the cell in the form of
ATP
mitochondria
➜ AKA Microbodies
➜ Small spherical, membranous organelles
➜ Crystalloid inclusion, nucleoid
➜ Production and degradation of H2O2
➜ Degradation of fatty acids
peroxisomes