Allied Health Symposium Notes

Flashcards from the Allied Health Symposium notes.

What is the purpose of the glucose transport and blood glucose levels discussion?

Relate cell biology to daily life and public health; Improve data interpretation and critical thinking

What is cell signaling and signal transduction?

Communication between cells from intercellular to intracellular and intracellular to intercellular

What is signal transduction?

A process that converts information carried by extracellular messenger molecules into cellular responses.

What are three types of signaling systems?

Autocrine, paracrine, and endocrine signaling.

What forms do extracellular signals take?

Mostly small chemicals: peptides, nucleotides, amino acids, steroids, eicosanoids, lipids, odorants, pheromones, hormones, gases. Also, Non-chemicals: mechanical stimuli (touch vibration, sound wave, or heat/cold or light…

What happens in autocrine signaling?

The cell has receptors on its surface that respond to the signals released by itself.

What happens during paracrine signaling?

The signaling molecules travel short distances through extracellular space.

What happens during endocrine signaling?

Signaling molecules reach their target cells through the bloodstream.

How do cell surface receptors work?

Receptors give information to the cell upon binding to signals (ligands) by activating a cascade of signaling relay events.

What are second messengers?

Small substances that activate (or inactivate) specific proteins, including kinases.

What is the role of kinases and phosphatases in cell signaling?

Kinases add phosphate groups, while phosphatases remove them.

What are the three amino acids that can be phosphorylated?

Serine, threonine, and tyrosine.

What are the classes of receptors?

G-protein coupled receptors (GPCR), enzyme coupled receptors (RTK), ligand-gated receptor (ion channels), contact-mediated receptor (integrins), and intracellular receptors like steroid hormone receptors (nuclear receptors, NO).

How are GPCRs involved in sensory detection?

Opsins in photoreceptors, odor receptors in olfactory sensory neurons, and taste receptors for bitter, sweet, or savory substances in taste receptor cells.

What are the natural ligands that bind to GPCRs?

Hormones, neurotransmitters, opium derivatives, chemical attractants, odorants, tastants, and photons.

What are the downstream effectors of activated Ga and βγ subunits?

Enzymes: adenylate cyclase (AC), protein kinases, phospholipase C (PLC), etc. and Ion channels: K+ channels, Ca2+ channels, etc.

What enzyme do G-proteins activate to produce second messengers?

Adenylyl cyclase, which produces cyclic AMP.

How is the signal amplified in GPCR signaling?

One ligand-bound receptor can activate many G proteins.

What does cAMP activate?

cAMP activates protein kinase A (PKA)

How are blood glucose levels regulated by hormones?

Glycogen phosphorylase controls glucose mobilization (stimulated by glucagon and epinephrine), and glycogen synthase controls glucose storage (activated by insulin).

How does glucagon or epinephrine binding to its receptor trigger a reaction cascade?

Gas subunit activates adenylyl cyclase, leading to cAMP formation.