Upload
alden-smith
View
53
Download
0
Tags:
Embed Size (px)
DESCRIPTION
CELL -CELL INTERACTIONS CH 11. Explain why this is the result of cell to cell communication. What characteristics are noted about cell communication here ?. I. Evolution of Cell Communication. Bacteria communicate with each other in order to respond to environmental changes - PowerPoint PPT Presentation
Citation preview
CELL -CELL INTERACTIONSCH 11
Explain why this is the result of cell to cell communication
What characteristics are noted about cell communication here ?
I. Evolution of Cell Communication
• Bacteria communicate with each other in order to respond to environmental changes
• The mechanism of cell communication is similar in both prokaryotes and eukaryotes:
• o Signal molecule secreted by one cell binds to receptor on target cell
• o Target cell responds • what does this tell us about the evolution of cell
communication?
. II. How cells communicate with each other
A. Local signaling: Direct contact and cell-cell recognition
B. Local signaling using local regulators: paracrine and synaptic signaling
• Signal molecules only travel short distances
C. Long distance signaling: endocrine signaling
• Involves hormones
• What characteristics are fundamentally the same in cell communication across the domains?
• What allows a cell to respond to a signal?
III. The transmission of a signal from one cell to another:
A. The 3 stages of cell signaling: • Reception: • Transduction: • Response:
Identify similarities and differences in these 2 modes of cell communication
B. Reception
• signal molecule binds to receptor causing it to change shape and become activated
• this binding is specific1. cell surface receptors:• hydrophilic signal molecules bind to
receptors that span the cell membrane
2. If it a steroid hormone (lipid soluble): • Steroid diffuses across phospholipid bilayer,
binds to its receptor in the cytoplasm, and travels to nucleus and either increases or decreases expression of certain genes
http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter18/animation__mechanism_of_steroid_hormone_action__quiz_1_.html
C. Signal Transduction :usually involves multiple steps
• Identify the 3 stages of cell signaling in this diagram
• What is happening during transduction?
• Binding of signal activates receptor • the receptor activates another protein,
which activates another, and so on, until the protein producing the response is activated
• Multistep pathways can amplify a signal: A few molecules can produce a large cellular response
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter7/animations.html
D. Response:
• Ultimately, a signal transduction pathway leads to regulation of one or more cellular activities
• The response may activate transcription
•The response may occur in cytoplasm