1. FROM BLOOD TO CELLS
Pancreas and liver regulate blood glucose in a feedback loop

2. FROM BLOOD TO CELLS
High blood glucose causes insulin in blood to bind to CM, triggering the movement of glucose transporters within the cell to the CM
at rest there aren't any glut 4 receptors without insulin binding and bringing them there. There are glut 2 receptors on the pancreas no matter what because glucose binds these first to stim insulin release from the pancreas. However, I would guess there are basal levels of insulin in the blood stream most of the time since there is always glucose in the blood. This insulin would just be acting to bring glucose into a small subset of tissues that needed it. For ex on cardiac tissue, which always needs some glucose. 

3. GLUCOSE AVAILABLE FOR RESPIRATION
Glucose in
ATP out

4. Created with Aspose.PowerPoint. Copyright 2004 Aspose Pty Ltd.
Evaluation only.
Created with Aspose.PowerPoint.
Copyright 2004 Aspose Pty Ltd.
Cells in organisms such as us constantly communicate with each other. This cellular discourse occurs through both electrical and chemical signals (Module 1: Figure cell communication ). Communication through electrical signals is very fast and depends upon the presence of gap junctions to allow information to pass directly from one cell to its neighbour. Communication through chemical signals is by far the major form of information transfer between cells. One cell releases a chemical stimulus (e.g. a neurotransmitter, hormone or growth factor), which then alters the activity of target cells. The latter have receptors capable of detecting the incoming signal and transferring the information to the appropriate internal cell signalling pathway to bring about a change in cellular activity.

5. The basic principle of a cell signalling pathway.
Stimuli (e.g. hormones, neurotransmitters or growth factors) acting on cell-surface receptors relay information through intracellular signalling pathways that can have a number of components. They usually begin with the activation of transducers that use amplifiers to generate internal messengers that either act locally or can diffuse throughout the cell. These messengers then engage sensors that are coupled to the effectors that are responsible for activating cellular responses. The green and red arrows indicate that cell signalling is a dynamic process consisting of ON mechanisms (green arrows) during which information flows down the pathway, opposed by the OFF mechanisms (red arrows) that switch off the different steps of the signalling pathway.

7. CELL SIGNALING
How do cells receive and respond to signals from their surroundings.
Prokaryotes and unicellular eukaryotes are largely independent and autonomous.
In multicellular organisms there is a variety of signaling molecules that are
secreted or expressed on the cell surface of one cell and bind to receptors expressed
by other cells. These molecules integrate and coordinate the functions of the cells
that make up the organism.

8. Overview: Cellular Messaging
Cell-to-cell communication is essential for both multicellular and unicellular organisms
Biologists have discovered some universal mechanisms of cellular regulation
Cells most often communicate with each other via chemical signals
For example, the fight-or-flight response is triggered by a signaling molecule called epinephrine
© 2011 Pearson Education, Inc.

9. Modes of cell-cell signaling
Direct cell-cell or cell-matrix (integrins and cadherins)
Indirect: Secreted molecules.
Endocrine signaling. The signaling molecules are hormones secreted
by endocrine cells and carried through the circulation system to act on
target cells at distant body sites.
Paracrine signaling. The signaling molecules released by one cell
act on neighboring target cells (neurotransmitters).
Autocrine signaling. Cells respond to signaling molecules that they
themselves produce (response of the immune system to foreign antigens,
and cancer cells).

10. Local and Long-Distance Signaling
Cells in a multicellular organism communicate by chemical messengers
Animal and plant cells have cell junctions that directly connect the cytoplasm of adjacent cells
In local signaling, animal cells may communicate by direct contact, or cell-cell recognition
© 2011 Pearson Education, Inc.

11. Neurotransmitter diffuses across synapse. Secreting cell
Figure 11.5a
Local signaling
Target cell
Electrical signal along nerve cell triggers release of neurotransmitter.
Neurotransmitter diffuses across synapse.
Secreting cell
Secretory vesicle
Figure 11.5 Local and long-distance cell signaling by secreted molecules in animals.
Local regulator diffuses through extracellular fluid.
Target cell is stimulated.
(a) Paracrine signaling
(b) Synaptic signaling

12. Gap junctions between animal cells Plasmodesmata between plant cells
Figure 11.4
Plasma membranes
Gap junctions between animal cells
Plasmodesmata between plant cells
(a) Cell junctions
Figure 11.4 Communication by direct contact between cells.
(b) Cell-cell recognition

13. Long-distance signaling
Figure 11.5b
Long-distance signaling
Endocrine cell
Blood vessel
Hormone travels in bloodstream.
Target cell specifically binds hormone.
Figure 11.5 Local and long-distance cell signaling by secreted molecules in animals.
(c) Endocrine (hormonal) signaling

14. In many other cases, animal cells communicate using local regulators, messenger molecules that travel only short distances
In long-distance signaling, plants and animals use chemicals called hormones
The ability of a cell to respond to a signal depends on whether or not it has a receptor specific to that signal
© 2011 Pearson Education, Inc.

15. The Three Stages of Cell Signaling: A Preview
Earl W. Sutherland discovered how the hormone epinephrine acts on cells
Sutherland suggested that cells receiving signals went through three processes
Reception
Transduction
Response
Animation: Overview of Cell Signaling
© 2011 Pearson Education, Inc.

16. EXTRACELLULAR FLUID CYTOPLASM Plasma membrane 1 Reception Receptor
Figure
EXTRACELLULAR FLUID
CYTOPLASM
Plasma membrane 1
Reception
Receptor
Figure 11.6 Overview of cell signaling.
Signaling molecule

17. Concept 11.2: Reception: A signaling molecule binds to a receptor protein, causing it to change shape
The binding between a signal molecule (ligand) and receptor is highly specific
A shape change in a receptor is often the initial transduction of the signal
Most signal receptors are plasma membrane proteins
© 2011 Pearson Education, Inc.

18. Relay molecules in a signal transduction pathway
Figure
EXTRACELLULAR FLUID
CYTOPLASM
Plasma membrane 1
Reception 2
Transduction
Receptor
Relay molecules in a signal transduction pathway
Figure 11.6 Overview of cell signaling.
Signaling molecule

19. Relay molecules in a signal transduction pathway
Figure
EXTRACELLULAR FLUID
CYTOPLASM
Plasma membrane 1
Reception 2
Transduction 3
Response
Receptor
Activation of cellular response
Relay molecules in a signal transduction pathway
Figure 11.6 Overview of cell signaling.
Signaling molecule

20. Concept 11.3: Transduction: Cascades of molecular interactions relay signals from receptors to target molecules in the cell
Signal transduction usually involves multiple steps
Multistep pathways can amplify a signal: A few molecules can produce a large cellular response
Multistep pathways provide more opportunities for coordination and regulation of the cellular response
© 2011 Pearson Education, Inc.

21. Signal Transduction Pathways
The molecules that relay a signal from receptor to response are mostly proteins
Like falling dominoes, the receptor activates another protein, which activates another, and so on, until the protein producing the response is activated
At each step, the signal is transduced into a different form, usually a shape change in a protein
© 2011 Pearson Education, Inc.