BIO 360 - Exam 1 - Chapter 6 Signaling SP 2023 PowerPoint Flashcards

1
Q

What is the Nernst Equation?

A
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2
Q

How do cells talk to each other?

A
  • electrical communication via gap junctions – direct
    cytoplasmic links between cells.
  • chemical communication via neurotransmitters,
    hormones, paracrine factors, contact-dependent
    molecules.
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3
Q

Major basis for classification is ______ over which
signal is transmitted.

A

distance

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4
Q

Physiological signals
* ______ ______
Changes in the membrane potential of a cell
* ______ ______
Secreted by cells into extracellular fluid (ECF)
Responsible for most communication within the body
Chemical signals are ______.
* Target cells, or targets, respond to signals

A

Electrical signals / Chemical signals / ligands

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5
Q

What is the role of gap junctions with direct contact and local cell-to-cell communication?

A
  • Gap junctions transfer both chemical and electrical signals.
  • They form direct cytoplasmic connections between adjacent cells.
    Local communication
  • Gap junctions create cytoplasmic bridges
  • Contact-dependent signals require cell-to-cell contacts,
  • Cell Adhesion Molecules transfer signals in both directions
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6
Q

Methods of cell-to cell communication
Local communication uses ______ and ______ signals.

A

Autocrine – same cell
Paracrine – different cells, close by

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7
Q

The nervous system uses a combination of chemical
and electrical signals for long-distance cell-to-cell
communication.
______ are chemical signals secreted by neurons
______, ______, ______.

A

Neurocrines / Neurotransmitters, Neuromodulators, Neurohormones

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8
Q

______ are chemicals secreted by neurons that diffuse across a small gap to the target cell. ______ use electrical signals as well.

A

Neurotransmitters / Neurons

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9
Q

Signal pathway - When does a cell responds to a particular chemical signal? What is an example of this?

A

Only if the target has a receptor, a binding protein.
Hormones are secreted by endocrine glands or cells into the blood. Only target cells with receptors for the hormone will respond to the signal.

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10
Q

What is the signal pathway?

A

The signal pathway:
* The chemical signal is a ligand that binds to the
receptor and is the first messenger
* Ligand-receptor binding activates the receptor
* The receptor activates one or more intracellular
signal molecules
* The last signal molecule modifies existing proteins or
initiates the synthesis of new proteins

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11
Q

Signal Pathways: Receptor locations
* ______ signal molecules diffuse through the cell membrane
Bind to receptors in the ______ or nucleus.
* ______ signal molecules bind to receptors on the cell
membrane.

A

Lipophilic / Lipophobic / cytosol

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12
Q

What are the four groups of membrane receptors?

A
  • G protein-coupled
  • Receptor-enzymes
  • Integrin receptors
  • Ligand-gated
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13
Q

Transmission of signal from one side of the membrane to
the other is called _______ ______.

A

signal transduction

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14
Q

______ ______ allows a small amount of signal to have a large effect. One ______ is ______ into many intracellular molecules.

A

Signal amplification / ligand / amplified

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15
Q

Figure 6.6c - Signal Transduction: Cascades and
Amplification

A

cAMP

cGMP

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16
Q

How does a receptor produce a 2nd messenger
inside cell?

A
  • Agonist binds to recognition site on plasma membrane and
    activates receptor (R*)
  • R* activates a transduction molecule, e.g. often a G protein
  • G protein* transfers signal to cell interior by interacting with
  • Effector molecule - often enzymes that catylize reactions in the cell.
17
Q

What is the difference between an agonist and antagonist ligand?

A

Agonist – ligand that activates the receptor
Antagonist – ligand that blocks the receptor

18
Q

Many receptors use a ___ ______ for signal transduction Proteins that bind GTP (guanosine triphosphate).

A

G protein

19
Q

cAMP made from ATP - reaction catalyzed by effector enzyme ______ ______ cytoplasmic side of plasma membrane.

A

adenylyl cyclase

20
Q

cAMP activates…

A

protein kinase A (PKA)

21
Q

What are kinases?

A

transfer phosphate group from ATP to a protein

22
Q

What two things are a major determinant of protein activity?

A

cAMP-dependent PKA phosphorylates & intracellular proteins

23
Q

What removes phosphates from proteins?

A

Phosphatases

24
Q

Card 30-37 in Powerpoint

A
25
Q

Card 38 Figure 6.6c Signal Transduction: Cascades and
Amplification

A
26
Q

Card 40-43

A
27
Q

______ Is an Important Intracellular Signal.
* Enters through ______ ______.
* Calcium is stored inside the ______ ______.
* Released from ______ messengers

A

Calcium / gated channels / endoplasmic reticulum / second

28
Q

Card 48-53

A