lecture 11 Flashcards
What is the purpose of cell junctions?
exchange nutrients and ions
How do animal cells exchange nutrients and ions?
Gap junctions
What are gap junctions made of?
channel proteins called Connnexin
How do plant cells exchange nutrients and ions?
Plasmodesmata
What is cell-cell recognition?
Receptor on one cell binds to a ligand on another
What are the two types of cell communication?
Cell junctions and cell-cell recognition
What is paracrine signaling?
The signaling molecule secreted by one cell is received by neighboring cell
What are the two types of local cell signaling?
Paracrine and Synaptic
What is synaptic signaling?
Neurotransmitter secreted by neuron is received by the target cell (muscle cells)
What is a type of long-distance signaling in cells?
Endocrine
What is endocrine signaling?
When a hormone secreted by the endocrine gland into the bloodstream reaches its target located at a distance
What are the three major steps to cell signaling?
Reception (start), Signal Transduction (process), Response (outcome)
What are the types of reception that can happen in cell signaling?
Direct contact, Paracrine (growth factors), synaptic (neurotransmitters), endocrine (hormones)
Where does signal transduction occur?
withing the cell, pathways and network
What is the response stage in cell signaling and give examples.
activation of cellular response; Metabolic activity, gene transcription
EX: cell survival, cell division, cell death
What does UV light do to DNA (name)?
causes pyrimidine dimers
What occurs to produce a pyrimidine dimer?
Adjacent T,T; C,T; or C,C fuse with new covalent bonds that cannot be ‘read’ by the cell
What happens when DNA damage is detected?
proteins working in a complex disassociate (p53 and MDM2)
What does a connection line with a perpendicular line mean in cellular damage map?
one protein is blocking or inhibiting the actions of another; it prevent mutations from being passed on to new cells
What does an arrow pointing at a protein mean in the cell diagram?
activation of another protein or pathway
What happens to the heart when fight or flight mode is activated?
heart rate increases and pumps blood
What happens to the lungs when fight or flight mode is activated?
bronchodilation -respiration
What happens to the liver when fight or flight mode is activated?
mobilize glucose
What is the function of Glycogen phosphorylase?
produces the cellular response to epinephrine
What is a ligand?
a signaling molecule
What is epinephrine known as?
Adrenaline
What are the size of ligands?
large or small
Examples of ligands in nature?
protein/carb/lipid/nucleotide/hydrocarbon
What do ligands do?
they bind to their own receptors- exhibits high specificity to is receptors
Where are G Protein coupled receptors located?
on the cell membrane
What is the function of G Protein coupled receptors?
transduce extracellular signals
What are the seven transmembrane domains in GPCR?
the protein parts that passes through the lipid membrane
What is the cytoplasmic domain in GPCR?
The part of the protein that goes deeper into the cytoplasmic and makes contact with the relay proteins (G proteins)
What is the order of the G protein signaling pathway?
1.) Signaling molecules is the first messenger, it binds to GPCR and activates it
2.) Activated GCPR binds to G protein then GTP binds to G protein
3.)Activated G protein binds to enzyme adenylyl cyclase and activates it
4.) Activated adenylyl cyclase converts ATP to cyclic MP (cAMP), which works as a second messenger
5.)cAMP activates a kinase important for metabolic activity inside cell
What does GCPR do in terms of cell signaling for animals?
transduces signals for the 5 senses
What is GCPR critical for?
drug delivery
About 50% of all prescribed drugs target a ___?
GCPR
