Unit 2 - The Cell Episode 4 Flashcards
located outside the nucleus
organelles are describe as membranous or non membranous
Cytoplasm
cytoplasm contains organelles and inclusions in an aqueous gel called the
cytoplasmic matrix
Human organism has different cell types derived from
Zygote
Membranous Organelles
Plasma Membrane
Endosomes
Lysosomes
Rough ER
Smooth ER
Golgi Apparatus
Mitochondria
Peroxisomes
undergo first cell division
Zygote
Zygote will produce cell called
blastomere
give rise to all cell/ tissue types
Blastomere
synthesize and kani-kanilang sariling protein depende kung what they want to become
Cell differentiation
under Cell differentiation:
the process where cells selects synthesize specific proteins/ specific molecules depending sa special function nila
Specialization process
muscle cells
Movement
cells of the digestive glands
Synthesize and Secrete enzyme
fat cells
Lipid Storage
fibroblasts
Extracellular Matrix
bone cells
Cartilage
Cell that formed adhesive and type junction:
Epithelial cells
controlled by the cell itself
contains solutes - inorganic ions and organic molecules
Cytoplasmic Matrix
can be convulated/ pleated
Membranous organelles
ex. of convulated membranous
Smooth ER
ex. of pleated membranous
inner mitochondrial membrane
A lipid-bilayered structure visible with transmission electron microscopy
It is composed of an amphipathic lipid layer containing embedded integral membrane proteins with peripheral membrane proteins attached to its surfaces
Plasma Membrane
Plasma Membrane is consists primarily of what molecules
Phospholipid, cholesterol, and protein
Plasma membrane is also known as
Plasmalemma
Transmission electron microscopy
2 electron dense layer separated by intermediate electron-lucent layer
The spaces enclosed by the organelles membrane particularly membranous organelles constitute now in __________
intracellular microcompartments
contains substrates, products, and other substances that degrade and synthesize
intracellular compartments
Electron-lucent layer is a ________________ layer
non-staining
in dividing and dying cells, and during cell movement, often manifests as morphologic changes in cell’s plasma membrane, which results in the formation of plasma-membrane blebs
Cell injury
dynamic cell protrusions of the plasma membrane
plasma-membrane blebs
is caused by the detachment of the plasma membrane from underlying actin filaments of the cell cytoskeleton
Blebbing
Cytoskeletal poisons that act on actin filaments such as ___________________ cause extensive membrane blebbing
phalloidin and cytochalasin-B
Phospholipid-cholesterol ratio is
1:1
consist of two non-polar (hydrophobic) long-chain fatty acids linked to a charged polar heads (hydrophilic) that bears a phosphate head
Membrane phospholipids
yung itsura ng plasma membrane/ cell is based from
Modified Fluid Mosaic Model
are incorporated directly in the lipid bilayer
major function is cell metabolism, cell regulation, cell integration
Integral proteins
Integral proteins can be better visualize using
Freeze Fracture
hahatiin sa gitna yung bilayered to see two interior faces of the membrane
Freeze Fracture
Integral proteins has two interior faces of the membrane
E face
P face
face backed by the Extracellular matrix
E face
face backed by Cytoplasm
P face
exhibit looser association with one of the two membranes particularly the inner
easily extracted by salt solutions
Peripheral proteins
Six broad categories of membrane proteins
Pumps
Channels
Receptors
Linkers
Enzymes
Structural Proteins
serve to transport certain ions (NA+) actively across membranes and also transport metabolic precursors of macromolecules (amino acids, sugars)
Pumps
allow the passage of small ions, molecules, and water across the plasma membrane in either direction (i.e., passive diffusion)
Channels
formed by membrane proteins that need receptors that will exhibit reactions, if these proteins are linked in the re receptors
gap junctions
allow recognition and localized binding of ligands
ex. - processes such as hormonal stimulation , coated-vesicle endocytosis, and antibody reactions
Receptor proteins
molecules that bind to the extracellular surface of the plasma membrane
ligands
anchor the intracellular cytoskeleton to the extracellular matrix protein (fibronectin)
simply act as bridge
Linker Proteins
have a variety of roles
Enzymes
Classification of enzymes
Oxidoreductases
Ligases
Lyase
Transferase
Isomerase
Hydrolase
are visualized by the freeze fracture method, especially where they form junctions with neighboring cells
simultaneously serve as receptor, enzyme, linker, or combination
structural proteins
protein: ion pumping
ATPase
major protein in the inner mitochondrial matrix
ATP synthase
Functions of Plasma Membrane
- Communication
- Intercellular connections
- Physical barrier
- Selective permeability
(Function of PM)
since it has receptor proteins therefore pwede siya sa signaling
Communication
(Function of PM)
-protects cellular contents
-support cell structure
Intercellular Connections
(Function of PM)
-separate outside from inside environment
Physical barrier
(Function of PM)
- regulating the passage of materials into and out of the cell and facilitating the transport of specific molecules
Selective permeability
-movement of substance down a concentration of gradient without expenditure of cellular energy
Passive Transport
- unassisted movement of small nonpolar substances across a selectively permeable membrane
- Walang kailangang proteins
Simple Diffusion
movement of ions and small, polar molecules down their concentration gradient across selectively permeable membrane by a transport protein
Facilitative diffusion
transfer small, water-soluble molecules.
They are highly selective, often transporting only one type of molecule
Carrier protein
Two classes of transport proteins
Carrier and Channel protein
- Examples: Na/K pump or H pump, and glucose carriers
- Pwede pang passive, pwede pang active
Carrier proteins
also transfer small, water-soluble molecules.
Pang passive lang
Channel proteins
Usually contain a pore domain that serves as the ion-selectivity filter
Transport can be regulated by membrane potentials, neurotransmitters or mechanical stress
Channel proteins
voltage-gated ion channels
membrane potentials
ligand-gated ion channels
ex. Acetylcholine receptors – can be seen on muscle cells
neurotransmitters
mechanically-gated ion channels
mechanical stress
diffusion of water across selectively permeable membrane.
Osmosis
movements of substances requiring expenditure of energy
Active transport
transport of ions or small molecules across the membrane against a concentration gradient by transmembrane protein pumps
Remember: carrier proteins – ex. pumps
Active transport
a process that involves configurational changes in the plasma membrane at localized sites and subsequent formation of vesicles from the membrane or fusion of vesicles with the membrane
pwede maging endocytosis or exocytosis
Vesicular transport
loob ng cell, enters the cell
Endocytosis
Uptake of fluid and macromolecules during ENDOCYTOSIS depends on three different mechanisms:
- Pinocytosis
- Phagocytosis
- Receptor-mediated endocytosis
pinakakilalang protein na gagamitin sa Endocytosis
Nakabase sa kaniya kung ano tawag sa kanila
Clathrin
is the nonspecific ingestion of fluid and small protein
aka Fluid-phase endocytosis
Pinocytosis
smaller invaginations lang ang nagfo-form diyan at nage-entrap dun sa extracellular fluid at mga solution na meron doon
Cell drinking
Mechanoenzymes are involved in pinocytotic vesicle scission ______________________
clathrin-independent endocytosis
di pa need ng clathrin kasi may pinching lang sa plasma membrane
clathrin-independent endocytosis
ex of Mechanoenzymes
GTPase (Guanosine triphosphatase/Guanosine triphosphate hydrolase)
is the ingestion of large particles such as cell debris, bacteria, and other foreign materials
Cell eating; Generally, a receptor-mediated process
Phagocytosis
Plasma membrane sends out pseudopodia to engulf phagocytosed particles into large vesicles called
phagosomes
requires depolymerization and repolymerization of the actin filaments for psuedopodial extension
Actin-dependent
phagocytosis is triggered by the recognition of
PAMPS (Pathogen associated molecular patterns)
recognition of PAMPS leads to activation of a nuclear factor __________transcription factor that regulates genes that control cell responses in phagocytosis
Kappa B
allows entry of specific molecules into the cell.
Receptor-mediated endocytosis
accumulate in well-defined regions of the cell membrane
kukunin niya yung cargo proteins
Cargo receptors
Clathrin interacts with the cargo receptor via another coating-protein complex, ________, which is instrumental in selecting appropriate cargo molecules for transport into the cells
adaptin
with the help of clathrin magkakaroon ng coated pits
Adaptin
helps to ingest cell: magkakaroon ng coated vesicle with the use of this
Dynamin
na nae-express on the pathogen’s surfaces by the toll-like receptors
PAMPS
(Pathogen associated molecular patterns)
Phagocytosis is clathrin-_____________ endocytosis
independent
Receptor-mediated endocytosis is clathrin- ____________________
Clathrin-dependent endocytosis
is the process by which a vesicle moves from the cytoplasm to the plasma membrane, where it discharges its contents to the extracellular space
labasg cell/exits the cell
Exocytosis
two general pathways of exocytosis:
- CONSTITUTIVE PATHWAY
- REGULATED SECRETORY PATHWAY
substances designated for export are continuously delivered in transport vesicles to the plasma membrane
vacuoles returns into the plasma membrane which is called cell membrane trafficking
CONSTITUTIVE PATHWAY
- Present to some degree in all cells
- TEM reveals that these cells lack secretory granules
- Seen in the secretion of immunoglobulins by plasma cells and procollagen by fibroblasts
CONSTITUTIVE PATHWAY
a regulatory event (hormonal or neural stimulus) must be activated for secretion to occur
REGULATED SECRETORY PATHWAY
Seen in specialized cells, such as endocrine and exocrine cells and neurons concentrate secretory proteins and transiently store them in secretory vesicles within the cytoplasm
Nagrerelease lang ng certain molecules pag kailangan
REGULATED SECRETORY PATHWAY