chapter 3 cell structure and function structure determines function. that which alters structure...
TRANSCRIPT
Chapter 3
Cell structure and function
• Structure determines function.
• That which alters structure alters function.
• Cells:
membranes─internal and external partitions
nucleus─genomic DNA
ribosomes─protein synthesis
endoplasmic reticulum ─synthesis and calcium dynamics
Golgi apparatus ─secreted proteins
mitochondria─ ATP synthesis
miscellaneous organelles
Chapter 3Cell structure and protein function
• Central dogma: genes to proteins
transcription (DNA to RNA) splicing (RNA to mRNA) translation (mRNA code determines amino acid sequence in protein synthesis)
• ATP/chemical energy: substrate/oxidative phosphorylation
• Enzymes and metabolic pathways
Chapter 3Cell structure and protein function (cont.)
Sizes, on a log scale.
Figure 3-2Cell Structure
Electron Micrograph of organelles in a hepatocyte (liver cell).
Figure 3-3
Organelles have their own membranes.
Figure 3-4 Human Cell
Membrane functions:
Electron micrograph and sketch of plasma membrane
surrounding a human red blood cell.
Figure 3-6Membrance structure
Ph
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Arrangement of integral and peripheral proteins
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Schematic cartoon of a transmembrane protein.
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Figure 3-8
Drawing of the fluid-mosaic model of membranes, showing the phospholipid bilayer and imbedded proteins.
Figure 3-9
Desmosomes provide strong attachments.
Figure 3-10a
Membrane junctions:
Tight junctions prevent leaks.
Figure 3-10b
Gap junctions communicate and coordinate.
Figure 3-10d
Connexons
{genomic DNA}
{site of ribosome assembly}Figure 3-11
Nucleus and nucleolus
Ribosomes
Figure 3-12
Endoplasmic reticulum:
Figure 3-13Golgi apparatus:
Figure 3-14 Mitochondria:
Endosomes: membrane-bound vesicular and tubular structures,Located between the plasma membrane and the golgi apparatusFunction as Golgi apparatus in sorting and modifying, and directiong Vesicles
Lysosomes:Are spherical or oval organellesHighly acidic, and contains digestives enzymes, To destroy bacteria
Peroxisomes:Dense oval bodiesH2O2 is toxic to the cell
Protein filaments function in movement and support.
Figure 3-15
Thank you for your attention,,,
NUCLEUS
The DNA code is “transcribed” into mRNA.
RIBOSOMES
The mRNA is “translated” to give instructions for proteins synthesis.
Figure 3-16