Some vocabulary
• Euglena complex Eukaryotic cell - self sufficient, swim, photosynthesize
• Prokaryote • Eukaryote • Protozoan (Paramecium) • vs. Metazoan, complex, starts as 1 cell.
Cells can multiply and divide
• Mitoses - daughter cells, become specialized • control of gene expression • (1) different genes turned on in different cells
(and at different times) • (2) ALL CELLS HAVE SAME GENES -
CELLS ARE DIFFERENT BECAUSE OF WHICH GENES ARE TURNED ON
• (3) but this can be fairly permanent, developmental change in gene regulation
Microscopy
light vs electron microscopy. • Dyes (that absorb light) are used to highlight
substructures in cells. • Consider, for instance, the word
"chromosome" which translates to "colored body."
• Similarly, electron dense materials, heavy metals like osmium, uranium and lead create an electron density in the EM.
Orientation
• membrane is a selective barrier to polar, charged, hydrophilic molecules and ions.
• These need to be pumped at the expense of energy or come through specific channels (pore molecules) through the membrane
• (more later in membrane coverage). • Eukaryotic cells have specific little bodies that
are the small cell parallel of organs in the body, and hence they are called "organelles."
In summary • rough endoplasmic reticulum where mRNA is
translated into protein, • "rough" - ribosomes seen in EM. • smooth ER - other reactions, steroid hormone • Liver hepatocytes detoxify. • Barbiturates induce an increase • "microsomal fraction," smooth ER • free ribosomes and polysomes • proteins that go to different places. • 10 amino acids per second
Traffic
• Golgi apparatus • receives vesicles from ER (at cis face) • secretory products that bleb off (from trans)
reactions after protein synthesis (post-translational modification of proteins)
• different routings for different proteins in cell. • inside the ER, Golgi complex, or vesicle is
outside the cell, • much like inside the gut is outside the body.
Mitochondria & Chloroplasts • Mitochondria- inner and outer membranes, • inner one with shelves called cristae. • ATP production • mitochondria (and chloroplasts), evolved from
prokaryotes, engulfed into eukaryotic cells; • They have some genes. • Also mitochondria are intimately involved in
programmed cell death (apoptosis) • pigments for photosynthesis, deployed in
multiple layers of membranes.
Lysosomes
• phagocytosis (phag - eat as in hyperphagic, eating too much, or bacteriophage, a virus that infects bacteria)
• Lysosomes merge and digest. • This also applies to autophagy, where
cell eats itself in a process of turnover of its components.