Histology - Cytoplasm Flashcards
Passive transport
Along an electrochemical concentration gradient
Ouabain
Inhibits the Na+-K+ pump
Active transport
Against a gradiant
Uniport transport
A single molecule moving in one direction
Coupled transport
Two different molecules moving in the same (symport) or opposite (antiport) direction
Paracrine signaling
Occure when the signaling molecule is released into the intercellular enviroment and affects cell in ints intermediate vicinity
Autocrine signaling
Is when the signaling cell is also the target cell = paracrine signaling
Endocrine signaling
The signaling molecule enters the blood stream to be ferried to target cells situated at a distance from the signaling cell
E.g on a hydrophobic hormone
Steroid hormones
E.g on a nonpolar molecule
Nitric oxide
E.g on a hydrophoilic hormone
Acetylcholine
ATP and cAMP are examples on…
the most common second messengers
Where is the small and the large subunit manufactured or assembled?
In the nucleolus
Sacroplasmic reticulum
Specialized SER in cells
What binds to the cytosolic surface of the RER?
Ribosomes
Polyribosomes:
A cluster of ribosomes that is connected by a strand of mRNA and is active in protein synthesis
AUG codes for…
methionin
Start codon
AUG
Which subunit does the peptidyl transferase belong to?
Peptidyl transferase bleongs to the large subunit
Peptidyl transferase function:
Transfere the amino acid from the tRNA on the P-site to the tRNA on the A-site
Stop codons?nonsense codon
- UAG
- UGA
- UAA
The release factor?stop codon bins to which site?
A-site
Where does the mannose phosphorylation occure?
Mannose phosphorylation occurs within the cis-face cisterna
Phagosome
Is the vesiclee used in phagocytosis
Dynamin
- A GTPase
- Molecule used to release pinocytotic vesicle.
Endosomal compartment=
Early endosome + late endosome
What is th pH of the early endosome?
pH = 6.0
What is th pH of the late endosome?
pH = 5.5
Different types of acid hydrolase
- Sulfatases
- Proteases
- Nucleases
- Lipases
- Glycosidases
Where can we find acid hydrolases?
Lysosomes
Lysosomes contains
hydrolytic enzymes
What happens with uncoated vesicles?
They fuse with late endosome
Residual body=
Lipids enclosed within the spent lysosome
Perixosomes
- Microbodies
- Contains enzymes like:
> Urate oxidase
> Catalase
> D-amino acid
Where are the proteins destined for perixosomes manufactured?
NOT in the RER, BUT in the cytosol
Does the perixosome posses its own genetic material?
No
Which phospholipid cna be found in the inner membrane?
Cardiolipin
Cardiolipin
Possesses 4 fatty acid chains
Contact sites
Where the outer and the inner mitochondrial membranes contact each other
Inner membrane have a lollipop-like subunit called…
ATP synthase
ATP synthase function
Responsible for the generation of ATP from ADP and inorganic phosphate
Where is the respiratory chain present?
In the inner membrane of mitochondria
The resporatory chain is composed of 3 respiratory enzyme complexes:
- NADH dehydrogenase complex
- Cytochrome b-c1 complex
- Cytochrome oxidase complex
These complexes form the electron transport chain
Where can we find lipids?
- In specialized cells like e.g. adipocytes
- Hepatocytes
Glycogen is storage form of….
Glucose
Lipids are the storage form of….
Triglycerides
Melanin are manufactured by….
Melanocytes of the skin and hair, pigment cells of the retina, and specialized nerve cells in the substantioa nigra of the brain.
Lipofuscin are
- Membrane-bound
- Formed from fusion of several residual bodies.
Inclusions:
- Glycogen
- Lipids
- Lipofuscin
- Melanin
- Crystals
Crystals
- Inclusion
- Location:
> Sertoli cells (crystals of Charcot-Bottcher)
> Interstitial cells (crystals of Reinke) of the testes
> Macrophages
Cytoskeleton’s major components:
- Thin filaments (microfilaments)
- Intermediate filaments
- Microtubules
Thin filaments
Composed of 2 globular subunits (G-actin) coiled around each other to for F-actin
Profilin and thymosin
Prevent the polymerization of the G-actin
What is the fastes growing end of the thin filament?
Faster-growing plus end and a slower-growing minus end
What attaches to the plus end of the thin filament?
Capping protein
Centrosome
Houses:
> Centroles
> “gamma”-tubulin ring complex
MTOC of the cell is called
Centrosome
Microtubule consists of…….
13 parallel protofilaments composed of heterodimers of the globular polypeptide “alpha”- and “gamma”-tubulin subunits.
Where is MAPs bound?
To the periphery to the microtubule
MAPs
Have dynein and kinesin
Does the procentriole posses microtubules?
No
What is the centrioles responsible for during the mitotic activity?
They are responsible for the formation of spindle appartus
Centrioles are the basal bodies that guide the formation of….
Cilia and flagella
Protoplasm
The living substance of the cell
Cytoplasm
Extends from the plasma membrane to the nuclear envelope
Karyoplasm
The substance forming the contents of the nucleus
