BIOLOGIA Receptory i kinazy

What are the key components involved in signal transduction through GPCRs and RTKs?

G protein, phospholipase C, PI 3-kinase, Ras-GEF, adenylyl cyclase, IP3, diacylglycerol.

What triggers the activation of intracellular signaling proteins?

Phosphorylation of key sites on the protein.

What is the main type of receptor found in plants for signal transduction?

Serine-threonine receptor kinases.

Which substances act as natural signal mimics at cell-surface receptors?

Nicotine, Morphine, Valium, Curare.

What is the role of the cytoskeleton in a cell?

Maintains cell shape, allows movement, and organizes organelles.

What distinguishes intermediate filaments from microtubules and actin filaments?

Intermediate filaments provide mechanical stability; microtubules are involved in transport; actin filaments enable cell motility.

What is the effect of mutations in keratin genes?

They can result in epidermolysis bullosa simplex, leading to fragile skin.

What is the relationship between myosin and actin during muscle contraction?

Myosin heads bind to actin, facilitating contraction through the sliding filament mechanism.

How do microtubules contribute to intracellular transport?

They serve as tracks for motor proteins like kinesins and dyneins to transport organelles.

What structural characteristic defines dynamic instability in microtubules?

The ability to grow and shrink independently at each end.

What triggers muscle contraction in response to excitation?

Calcium ions (Ca2+) released from the sarcoplasmic reticulum bind to proteins that enable interaction between actin and myosin.