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Labs:
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Notes:
Animal Body
Arthropods
Biochem
Cell Cycle
Cell Interactions
Cell Structure
Circulation
Respiration
Communities
Digestion
DNA
Ecosystems
Energy
Evolution Evidence
Future of
Biosphere
Genetic Engineering
Gene Function
Genetics
Hormones
Human Evolution
Immunity
Species
Interaction
Kidneys
Locomotion
Membranes
Mollusks
Mutation
Nervous
Non-Coelmic
Photosynthesis
Plant Physiology
Population Genetics
Population
Dynamics
Cellular Respiration
Sensory
Speciation
Taxonomy
Vertebrates
Vertebrate
Org
Vocabulary:
1,2,3,4,5,6,7,8,9,10,
11,12,13,14,15,
16,17,18,19,20,
21,22,23,24,25,
26,27,28,29,30,
31,32,33,34,35,
36,37,38,39,40,
41,42,43,44,45,
46,47,48,49,50,
51,52,53,54
Cell Interactions
I. Cell – Cell Interactions
A. Cells communicate using signal molecules and membranes
B. Signals are proteins, amino acids, lipids, dissolved
gases and nucleotides
C. Signals are highly specific as are the receptors
D. Receptor proteins receive signals; undergo a conformational
change which produces a cellular response
II. Types of Signals
A. Direct Contact – between adjacent cells through
gap junctions
Ex. Early Development
B. Paracrine – short lived, local effects
Ex. Early Development
C. Endocrine – hormones; effect occurs at a target
cell far away from production site (needs circulatory system)
D. Synaptic – neurotransmitters across a synapse
in animals (short-lived; one area)
III. Types of Receptors
A. Intracellular Receptors (lipid soluble)
· Signals directly enter target cell
· Bind to internal receptor and initiate a response
1. N, O – gas which binds to
a receptor (enzyme)
a. Activates the enzyme
b. Synthesis of cyclic GMP (messenger)
· **Deletes smooth muscles of blood vessels**
2. Gene Transcription
a. Cortisol, estrogen, progesterone, v.t.d., thyroid hormone
b. Can’t bind DNA; signal opens the binding site; DNA binds; activates
gene
B. Cell Surface Receptors
· Convert external signals to internal responses
· 3 Super Families
A. Chemically Gated Ion Channels
1. Form a pore in middle of protein
2. Specifically for individual ions
3. Multi pass
B. Enzyme Receptors
1. Activated by signal binding
2. Causes this enzyme to phosphorylate
protein Kinesis
3. Single pass
4. Inside portion – carries out
the enzyme activity
5. Outside portion – binds signal
C. G-protein Linked Receptors
1. Act indirectly plasma membrane
bound enzyme of ion channels
2. Use an assisting protein called
GTP binding protein (G-Protein)
3. G-protein is a 7 pass protein
4. Signal molecule binds to receptor
5. Cause conformational change
6. Causes the G-protein to bind GTP
and become activated
7. Activated G-protein releases from
the receptor and floats away to initiate a response elsewhere
IV. Second Messenger
A. G proteins and other receptor need help getting their
message to the cytoplasm
B. These molecules or ions do this by binding to the
protein and altering its shape
C. Examples
1. cAMP
2. Calcium (CA++)
V. Amplification of Signals
A. Occurs through protons; kinase cascades
B. Receptor phosphorylates a stage one protein
C. Stage one proteins activate many stage two proteins
D. Overcome the blunting of the signal caused by slow
diffusion and cytoplasmic interference and distance
VI. Cell Identity
A. Cell surface receptors have carbohydrate chains attached
to them which help them function as cell markers (glycocalyx)
B. Glycolipids
1. Function in tissue specificity
2. Distinguish between kidney vs.
brain vs. toe
3. Markers are read by adjacent cells
C. Glycoproteins
1. Function in “self-recognition”
2. Distinguish Amanda cells from Kim
cells
3. MHC = Major Histocompatibility
Complex
4. All people make specific set of
MHC proteins
5. Single pass immunoglobulins
VII. Intercellular Adhesions
A. Types of connections between adjacent cells
1. Tight junctions
2. Gap junctions
3. Anchoring Junctions