Cell-to-Cell Communication

Question 1

What are the two types of cell to cell communication?

Answer 1

Direct and Indirect

Question 2

What are the mechanisms of communication for direct?

Answer 2

Gap Junctions and anchored extracellular messengers

Question 3

What are gap junctions and how to the allow for cell-cell communication?

Answer 3

cells that connect to the cytoplasm of other cell and allow for direct transfer of ions, small molecuels and second messengers. Chemical.

Question 4

what are anchored extracellular messengers?

Answer 4

signal molecule anchored in plamsa membrane. Interacts with other cells’ receptor

Question 5

what are the mechanisms’ of indirect cell communication?

Answer 5

Secreted extracellular messengers (chemical) or target cell receptors. Paracrine, Endocrine, Autocrine, Neurocrine

Question 6

What does paracrine chemicals act on and an example?

Answer 6

proximal cell, histamine

Question 7

what does autocrine chemical act on and what does it achieve?

Answer 7

same cell released from and limits release of a chemical.

Question 8

what does neurocrine act on?

Answer 8

neurons or a target cell

Question 9

what are the three types of neurocrine messengers?

Answer 9

Neurotransmitters, neuromodulaors and neurohormones

Question 10

Neurotransmitters

Answer 10

single molecule moves across synapse to target cell/neuron

Question 11

neuromodulators

Answer 11

chemical that effects the neurotransmission of nearby neurons.

Question 12

What are neurohormones?

Answer 12

release by neurosectertory hormones and diffuse through the blood.

Question 13

What are the types of chemical messengers?

Answer 13

Modified amino acids, peptides, polypeptides/proteins, amines and steroids.

Question 14

what are two examples of a modifed amino acid?

Answer 14

Adrenaline and Noradrenaline

Question 15

what are two examples of a steroid?

Answer 15

estrogen and progesterone

Question 16

what are two examples of peptides?

Answer 16

ADH, Oxytocin

Question 17

what are two examples of polypeptides?

Answer 17

FSH and insulin

Question 18

what are the two characters that chemical messengers are split up by?

Answer 18

Lipophobic and lipohilic

Question 19

what is lipophobic and and where are their receptors?

Answer 19

water soluble but not lipid soluble that dissolves in blood. Cell membrane

Question 20

what is lipophilic and where are its receptors?

Answer 20

water insoluble but lipid soluble. inside the cell (mostly)

Question 21

Which type of cell messenger can cross cell membranes?

Answer 21

cells that are Lipophilic

Question 22

what chemical messengers are directly encoded in our DNA?

Answer 22

protiens, peptides and polypeptides.

Question 23

what chemical messengers are produced by intracellular biosynthetic pathways?

Answer 23

Steriods

Question 24

intracellular

Answer 24

located/occuring within the cell

Question 25

intercellular

Answer 25

located/occurring between cells.

Question 26

Why are chemical messengers food for cell to cell communication?

Answer 26

they don't have nay other biomedical role so are available and effective. They are useful for long distant communication, are rapid and have specific targets and functions.

Question 27

what is the role of receptors in cell-cell communication?

Answer 27

allow messenger molecules and proteins to bind to their target cell. Membrane receptors allow for the transcription of specific proteins.

Question 28

what are the different types of membrane receptors?

Answer 28

Receptro channels, receptor-enzyme, G Protein Coupled receptor and integrin.

Question 29

What is the mode of action for receptor channels?

Answer 29

Chanel opens, channel might be linked to G-protien = second messenger created, other channels open and respond to second messenger.

Question 30

What are receptor-enzyme membrane receptors?

Answer 30

Receptors that are linked to or have enzymatic activity.

Question 31

What is the mode of action for receptor-enzymes?

Answer 31

Signal molecule binds, receptor channel opens, channel linked to G-Protein, second messenger created, other channels open and respond to second messengers.

Question 32

What is a GPCR?

Answer 32

member of the superfamily of G-binding proteins that have a three-part membrabe transductor.

Question 33

what is the role of GPCR in cell communication and when does it activate?

Answer 33

Role in second messenger transmission. Activated when ion channels open or enzyme activity occurs.

Question 34

what is the subunit of GPCR involved in the cAMP second messenger?

Answer 34

a

Question 35

What is the mode of action of the GPCR in the pathway involving cAMP?

Answer 35

ligan binds to receptor protein and changes conformation --> causes GDP to become GTP in a unit (active) --> a subunit dissociates and binds to effector molecule

Question 36

what are intracellular biosynthesis pathways?

Answer 36

Connection of cell surface to nucleus creating change in gene expression.

Question 37

what is intercellular pathways and its roll in cell-cell communication?

Answer 37

signals that travel throughout the body and allows glands to produce signals that will act on different tissues?

Question 38

What are three important second messengers?

Answer 38

cAMP, Calcium and DAG.

Question 39

True or false: Second messengers have to be membrane bound?

Answer 39

true

Question 40

What are the actions of second messengers?

Answer 40

alter ion gating channel, increase intracellular calcium and change enzyme activity.

Question 41

What is the general structure of how second messengers communicate?

Answer 41

The signal molecule binds to a receptor and activates proteins --> proteins become amplifier enzyme --> enzyme creates signal messenger --> second messenger activates something --? phosphorylates to create a response.

Question 42

What are the steps required to make cAMP and the resulting actions?

Answer 42

signal molecule binds to GPCR --> G-protein activates --> turns on adenylyl cyclic (amplifier) --> converts ATP into cAMP --. activates protein kinase A --> phosphorylates other proteins

Question 43

Name the different types of neurotransmitters

Answer 43

AcetyChline, Catecholamines, Amino acids, morphine-like substances and peptides.

Question 43

What are the two types of neurotransmitters?

Answer 43

inhibitory and exhibitory

Question 44

How do inhibitory neurotransmitters help in chemical communication?

Answer 44

They cause the polarisation of postsynaptic membranes and supresses action potentials

Question 45

what are examples of inhibitory neurotransmitters?

Answer 45

GABA and Glycine

Question 46

How do exhibitory neurotransmitters help in chemical communication?

Answer 46

Causes depolarization of postsynaptic membranes and promotes action potentials.

Question 47

What are the main differences between hormones and neurohormones?

Answer 47

where secetred from and who communication between (NH= neuron --> neuron targets)

Question 48

What is the source of the second messenger calcium?

Answer 48

through ion channel's pr from ER

Question 49

What is the effect of calcium?

Answer 49

When 4 are present it will unlock calmodulin which activates calmodulin-dependent protein kinase. This then allows for the phosphorylation of other proteins and a cascade of enzyme activity.

Question 50

what is the source of DAG?

Answer 50

GPCR activates Phosphiliaose C which then generates DAG.

Question 51

what is the effect of DAG?

Answer 51

with calcium, activates protein Kinase C which results in the phosphorylation of other proteins.

Question 52

Which characteristics of receptors can bind to receptors in the cytoplasm?

Answer 52

lilophobic