a&p - ch.3 (marieb, 8th ed.)
DESCRIPTION
Marieb's 8th edition A&P book.Chapter 3 powerpointTRANSCRIPT
1
Phospholipid structure
Amphipathic molecule (phosphatidyl choline)hydrophobic part: fatty acidshydrophilic part: phosphate & choline
2
Membrane structure
3
Membrane components
4
Transmembrane proteins
5
Intercellular structures
Desmosomes
“spot welds”, dense proteins (cytoplasm & intercellular) fibers (intermediate filaments) extend across cells
epithelial cells (especially skin), cardiac intercalated disks
Tight junctions
cell “collar”, block large molecules, no lateral protein movement
epithelial cells
Gap junctions
cell-cell communication, small molecules (<1000 MWt)cardiac intercalated disks, smooth muscle
6
Desmosomes
fig 3-10a
“spot welds”, dense proteins (cytoplasm & intercellular)
fibers (intermediate filaments) extend across cells
epithelial cells (especially skin), cardiac intercalated disks
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Tight junctions
fig 3-10b
cell “collar”, block large molecules, no lateral protein movement
epithelial tissue (esp. kidney, gut)
paracellular pathwaybetween cells
8
Gap junctions
fig 3-10d
cell-cell communication, small molecules (<1000 MWt)
cardiac intercalated disks, smooth muscle
9
Epithelial cell
fig 3-10c
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Protein ligand interaction
Proteins could be: Ligands would be:
enzymes substrates, allosteric regulators
receptors chemical messengers
transporters transported substances
transcription factors transcription regulators
any of above drugs
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Protein-ligand binding properties
Specificity:binding depends on ligand size, shape, charge
Affinity:strength of binding: i.e. [ligand] at 50% binding
Saturation:there is a finite number of binding sites
Competition:structurally similar molecules can compete for binding
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Specificity
binding depends on ligand size, shape, charge
fig 3-26 fig 3-27
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Specificity
protein Y specificity
greater than
protein X specificity
fig 3-28
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Affinity
strength of binding: i.e. [ligand] at 50% binding
fig 3-29
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Affinity & saturation
strength of binding: i.e. [ligand] at 50% binding
fig 3-30
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Affinity (different proteins)
strength of binding: i.e. [ligand] at 50% binding
fig 3-31
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Affinity (different ligands)
strength of binding: i.e. [ligand] at 50% binding
18
Protein-ligand binding properties
Specificity:binding depends on ligand size, shape, charge
Affinity:strength of binding: i.e. [ligand] at 50% binding
Saturation:there is a finite number of binding sites
Competition:structurally similar molecules can compete for binding
and remember:the protein can be an enzyme, receptor, transporter, etc.
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Regulating binding site properties
a. Allosteric modulationreversible binding at another (“allo-”)
sitecan be activation or inhibition
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Regulating binding site properties
a. Covalent modulationchemical alteration of the proteincan be activation or inhibition
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Metabolism (pathways)
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Metabolism (key)
Key:A: glycogenesis, B: glycogenolysis, C: glycolysis, C+D: anaerobic
glycolysis (lactic acid fermentation), E: gluconeogenesis, F: irreversible step (pyruvate dehydrogenase), G: protein synthesis, H: proteolysis, I: lipogenesis, J: lipolysis, K: Krebs cycle, L: urea synthesis, M: ketogenesis
Anabolic pathways: A, G, I
Catabolic pathways: B, C, E, F, H, J, K
Liver only: E, L, M
Mitochondrial: K
Ribosomal: G
Smooth endoplasmic reticulum: I
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Energy content