-
primary lysosomes
- originate from the golgi apparatus
- contain digestive enzymes - macromolecules are hydrolyzed into monomers
(page 26 on slide)
-
Food enter the cell by __
phagocytosis - a phagosome is formed
-
Phagosomes
fuse with primary lysosomes to form secondary lysosomes
(page 28 on slide)
-
Enzymes in the secondary lysosome __
hydrolyze the food molecules
-
Lysosomes digest cell materials. This is called __
autophagy
Cell components are frequently destroyed and replaced by new ones.
-
Cells that require a lot of energy have a lot of __
mitochondria
-
In the mitochondria, __
energy in fuel molecules is transformed to the bonds of energy - rich ATP: cellular respiration
-
The inner membrane of a mitochondria folds inward to form __ This creates __
cristae; a large surface area for proteins involved in cellular respiration reactions
(page 31 on slide)
-
The mitochondrial matrix contains __
-
The space between the inner and outer membrane of a mitochondria is called the __
intermembrane space
(page 32 on slide)
-
chloroplasts
site of photosynthesis - light energy is converted to the energy of chemical bonds
have a double membrane
-
__ are stacks of __ - made of circular compartments of the inner membrane of a chloroplast
Grana; thylakoids
(page 35 on slide)
-
Thylakoids contain __
chlorophyll & other pigments that harvest light energy for photosynthesis
-
Stroma
- fluid in which grana are suspended
- contains DNA & ribosomes
- (plant version of mitochondria matrix)
(page 35 on slide)
-
How did eukaryotic cells originate?
- Some organelles may have arose by symbiosis "living together"
- endosymbiosis theory: Mitochondria & plastids arose when one cell engulfed another cell
(page 36 on slide)
-
functions of the cytoskeleton
- holds organelles in position or moves them
- cytoplasmic streaming
- changes the shape of the cell (critical for neurons: development, injury, learning, memory)
- interacts with extracellular structures to stabilize the cells
-
3 components of cytoskeleton
- microfilaments
- intermediate filaments
- microtubules
(page 39 on slide)
-
microfilaments
- help a cell or parts of a cell to move
- determine cell shape
- made from the protein actin (also called actin filaments)
- In some cells, forms a meshwork just inside the cell membrane, which provides structure (ex. microvilli)
(page 40 on slide)
-
Actin has + and - ends and __ to form __
polymerizes; long helical chains (reversible)
(page 40 on slide)
-
intermediate filaments
- tough, ropelike protein assemblages
- anchor cell structures in place
- resist tension
- axon growth
(page 42 on slide)
-
microtubules
- form rigid internal skeleton in some cells
- made from the protein tubulin - a dimer
- have + and - ends
- can change length rapidly by adding pr losing dimers (polymerization & de-polymerization)
-
Cilia & flagella use __ to power motion.
microtubules
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