4. Cell Architecture Flashcards
Name functions (6) of the cytoscaffold?
- Cell polarity.
- Chromosome movement.
- Shape.
- Strength.
- Anchoring.
- Motility.
What kind of cell movement (5) does the cytoscaffold facilitate?
- Crawling.
- Chemokinesis.
- Chemotaxis.
- Endocytosis.
- Exocytosis.
What does CHEMOKINESIS mean?
Increased nondirectional activity of cells due to the presence of a chemical.
What does CHEMOTAXIS mean?
Organised/directional movement in response to chemical.
What are the types (3) of cytoscaffolds?
- Microtubules.
- Microfilaments.
- Intermediate filaments.
How many strands (protofilaments) do INTERMEDIATE filaments contain?
8
What proteins do INTERMEDIATE filaments contain?
- Keratin.
- Vimentin.
- Desmin.
- Lamins.
- GFAP.
- Neurofilament.
What is KERATIN?
A scleroprotein that forms intermediate filaments.
What is a SCLEROPROTEIN?
Protein characterized by its insoluble structure - is not degraded by hydrolytic enzymes.
What is a HYDROLYTIC enzyme?
Catalysis hydrolysis.
What is VIMENTIN?
A protein that co-polymerizes with other subunits (desmin) to form the intermediate filaments.
What is DESMIN?
A protein that co-polymerizes with other subunits (vementin) to form the intermediate filaments.
What is GFAP?
Glial fibrillary acidic protein - accessory protein of Intermediate filaments.
What is LAMIN?
A protein that forms intermediate filaments.
What is NEUROFILAMENT?
Element that forms a neural fibril intermediate filament.
What is the diameter of a intermediate filament?
10 nanometres.
How are MICROFILAMENTS formed?
Treadmilling.
What does TAU PROTEIN do?
Regulates microtubules.
What do TAU AGGREGATES cause?
HYPER-phosphorylation > can lead to altzeimers.
What forms a MICROTUBULE dimer?
Alpha and beta tubulin sub-units.
Which type of cytoscafold forms parts of the AXONEME?
MICROTUBULE.
What type of cytoscafold is responsible for spindle formation?
MICROTUBULIN
How many strands (protofilaments) do MICROTUBULES contain?
13
What kind of axonal transport are there?
- ANTEROGRADE.
- RETROGRADE.
What motor protein is responsible for RETROGRADE axonal transport?
KINESIN
What motor protein is responsible for RETROGRADE axonal transport?
DYNEIN
What processes is KINESIN important for?
- Microtubule formation.
- Mitosis.
What is the SLIDING TUBULE MECHANISM?
Actin and myosin filaments slide in and out between each other to form a muscle contraction.
What is the function of NEXIN (protein) LINKS?
Preventing microtubules in axonemes from movement.
What is the 9+2 formation?
The formation of microtubule doublets in an axoneme.
What causes movement in CILIA and FLAGELLA?
Sliding tubule mechanism.
What is the monomer of a MICROFILAMENT?
GLOBULAR ACTIN
Which cytoscafold protein complex is required for cell movement?
MICROFILAMENTS
Which cytoscaffold protein complex has a contractile nature?
MICROFILAMENTS
What (2) ways can MICROFILAMENTS be arranged?
- Parallel bundles.
- Criss-cross.
What are the (3) possible modifications that can be made to a cytoscafold protein complex?
- Cross-Links.
- Cutting.
- Binding Proteins.
How many strands (protofilaments) do MICROFILAMENTS contain?
7
What is required for membranes to fuse?
GTP energy
What is GTP?
Guanasine triphosphate.
What processes does GTP provide energy for?
- Transcription.
- Translation.
- Membrane fusion.
How does snake venom work?
It is a PHOSPHOLIPASE > destroys the link between fatty acid tails.
What is a GLYCOCALYX?
Glycoprotein, polysaccharide surrounding bacteria and some epithelial surfaces.
What is the importance of CHOLESTEROL within a plasma membrane?
Keeps membranes fluid (acts like a temp and pH buffer)
What percentage of the plasma membrane is cholesterol?
20%
What is a CYTOKINE?
Intercellular mediators of immune responses.
Name the (5) different types of CYTOKINE?
- Chemokine.
- Interferon.
- Interleukine.
- Lymphokine.
- Tumour necrosis factor.
What does CHEMOKINE mean?
Group of small cytokines with the ability to induce chemotaxis or chemokinesis.
What does TRANSLOCATION mean?
Change of location.
What does INTRALUMINAL mean?
Within lumen of tube.
What are LEUKOCYTES?
White blood cells.
What is ACTIN?
Contractile protein filament, containing ‘active’ or ‘binding’ sites.
What are the (4) motility processes?
- Gel-sol transitions.
- Lamelipodial extentions.
- Actin-myosin interactions.
- Focal adhesions.
What are MYOSIN 1?
Motor protein for moving membranes.
What is MYOSIN 2?
Motor protein for muscle contractions.
What is INTEGRIN?
Transmembrane proteins involved in cell adhesion, motility and in signal transmission.
What is FIBRONECTIN?
Glycoprotein that connects INTEGRIN to the ECM.
What is a MYOFIBRIL?
Cylindrical organelle running the length of the muscle fibre, containing Actin and Myosin filaments.
What is a SARCOMERE?
Functional unit of the Myofibril, divided into bands (I, A and H)
What is TROPOMYOSIN?
Actin-binding protein which regulates muscle contraction.
What is TROPONIN?
A complex of three proteins, attached to Tropomyosin.
What are MYOSINS?
Motor proteins, containing MYOSIN HEADS.
What is the RATCHET MECHANISM?
Repeated pulling of the actin over the myosin during muscle contraction.
