Chapter 11- Cell Communication

Chapter 11- Cell Communication - 1/31/2010...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1/31/2010 1 Cell Communication © 2010: D. Julian Individual rod- shaped cel s 1 Evolution of cell signaling A signal transduction pathway is a series of steps by which a signal on a cell’s surface is converted into a specific cellular response. Pathway similarities suggest that ancestra Communication among bacteria Spore-forming structure (fruiting body) Aggregation in process Fruiting bodies 0.5 mm 3 2 © 2010: D. Julian ancestral signaling molecules evolved in prokaryotes and were modified later in eukaryotes. Local and long distance signaling Cells in a multicellular organism can communicate by chemical messengers. Animal and plant cells have cell junctions that directly connect Plasma membranes Gap junctions between animal cells Plasmodesmata between plant cells the cytoplasm of adjacent cells. In local signaling, cells may communicate by direct contact, or cell cell recognition. © 2010: D. Julian (a) Cell junctions (b) Cell-cell recognition
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1/31/2010 2 Target cell Electrical signal along nerve cell triggers release of neurotransmitter Local signaling In local signaling, cells may communicate by direct contact, or cell cell recognition. Some animal cells communicate using local regulators, messenger molecules that travel only short distances. Secretory vesicle Secreting cell Local regulator diffuses through extracellular fluid (a) Paracrine signaling (b) Synaptic signaling Target cell is stimulated Neurotransmitter diffuses across synapse © 2010: D. Julian Long distance signaling In long distance signaling, plants and animals use chemicals called hormones. Endocrine cell Blood vessel Hormone travels in bloodstream © 2010: D. Julian to target cells Target cell (c) Hormonal signaling Three stages of cell signaling 1. Reception 2. Transduction 3. Response EXTRACELLULAR FLUID Plasma membrane CYTOPLASM Transduction Response 2 3 Reception 1 © 2010: D. Julian Receptor Signaling molecule Relay molecules in a signal transduction pathway Activation of cellular response
Background image of page 2
1/31/2010 3 Reception © 2010: D. Julian Reception For signal reception, a signal 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.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/31/2011 for the course BSC 2010 taught by Professor Bowes during the Spring '08 term at University of Florida.

Page1 / 10

Chapter 11- Cell Communication - 1/31/2010...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online