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Most cells are between __ in diameter and are visible only under microscope.
1 and 100 μm
Genetic control of the cell: __
The nucleus houses __, directs __ by __ from __, which is then transported ot the __ via __ and turns into a __.
- most of the cell's DNA
- protein synthesis
- nuclear pores
1. Contains most of the __
a. Complex of DNA and proteins making
up chromosomes is __
b. Characteristic __of
i. Humans: __/ sex cells: __
- genes in chromosomes (one long DNA molecule)
1. Enclosed by __, which does what?
a. It is a __, each a lipid bilayer with proteins and separetaed by __
b. Perforated by __that are continuous with __
i. Explain pore complex?
c. Nuclear side of envelope lined by __, a netlike array of protein filaments that does what?
i. This and nuclear matrix may help __.
- nuclear envelope
- separates it from contents of cytoplasm
- Double membrane
- lines each pore and plays role in regulating entry and exit of proteins and RNAs and macromolecules
- nuclear lamina
- maintains the shape of the nucleus by mechanically supporting the nuclear envelope
- organize genetic material
1. __forms __by instructions of DNA
a. Proteins imported from the cytoplasm are assembled with rRNA into large and small subunits of ribosomesà exit nucleus through pores
__, which use information from the DNA to make proteins
Made of __; carry out __
- ribosomal RNA and protein
- protein synthesis
Ribosomes build protein in two cytoplasmic areas
- a. Free: in cytosol
- ----- Proteins made funcition within cytosol
- b. Bound: attached to outside of ER or nuclear envelope
- ------ Make proteins destined for insertion into membranes, for packaging within certain organelles, or for export from the cell
- c. Both identical and can alternate between roles
Endomembrane System carries out variety of tasks, such as __, __, __, and __. They do not have identical membranes
- protein synthesis
- transport into membranes and organelles or out of cell
- metabolism and movement of lipids
- and detox of poisons
What are the structures of the endomembrane system?
- nuclear envelope
- Golgi apparatus
- plasma membrane
1. More than half the__ in eukaryotic cells
2. Consists of membranous tubules and sacs called __
3. Speratares the __ from the __
- total membrane
- internal compartment of the ER, called the ER lumen (cavity) or cisternal space
- 1) lacks ribosomes
- 2) synthesizes lipids (oils, phospholipids, sex hormones and steroids)
- 3) metabolizes carbs
- 4) detox of drugs and poisons
- 5) stores Ca ions
Explain how the SER detoxifies drugs adn poisons?
- Involves adding –OH groups to make
- drugs more soluble
- Drugs induce proliferation of
- smooth ER, thus increasing the rate of detox , which increases tolerance, and
- more doses are required to achieve desired result
Explain how the SER stores calcium ions?
- i. Pumps calcium ions from the cytosol to the ER lumen
- --1. Calcium ions rush iinto cytosol when stimulated by nerve cell to cause movement
- 1) studded with ribosomes on outer surface
- 2) growth of polypeptide chain occurs through bound ribosomes and threaded into ER lumen through pore formed by protein complex
- --- most secretory proteiins are glycoproteins
- 3) after formed, they are separated from free proteins adn depart from transitional ER
- 4) membrane factory
Explain rough ER's function as membrane factory?
- i. Grows in place by adding membrane proteins and phospholipids to its own membrane
- 1. Anchored by hydrophobic portions
- ii. Makes phospholipids
- iii. Vesicles tranferr its items
1) Products of ER are __ and __ and set to other destinations.
a) __ are modified.
2) Consists of flattened membranes called __.
a) The membrane of each separates its internal space from cytosol
3) Manufactures __.
4) Beofre products depart, they are __ and __ to various parts.
a) __ aid in sorting
b) Transport vesicles from the Golgi may have external molecules on membranes that recognize __ on the surface of specific organelles or on the plasma membrane
- modified and stored
- glycoproteins' carbohydrates
- some macromolecules
- sorted and targeted
- molecular ID
- docking stations
Explain the membranes of cisternae on golgi.
- b. Membranes of cisternae on opposite sides of a stack differ in thickness and molecular composition; products are modified during transit from cis region to trans region
- i. Cis face: located near ER
- 1. a vesicle that buds from the ER can add its membrane and contents of its lumen to the cis face through fusion
- 2. trans face
- a. gives rise to vesicles that pinch off
Explain the golgis funciton of manufacturing macromolecules.
- a. Like secretory proteins, nonprotein Golgi products depart from trans face and fuse with plasma membrane
- b. Manufactures in stages
- i. Cisternal maturation model: cisternae of the Golgi progress forward from cis to trans face, carrying and modifying their cargo as their move
a. excess leakage can __ cell due to __
2. __ and __ are made by __and transferred to __for further processing
3. some Lysosomes arise by __
4. 3D shapes of proteins in Lysosomes protect __
5. __ digestion
6. Engage in autophagy, which is __?
- hydrolytic enzymes
- lysosomal membrane
- rough ER
- budding from trans face
- vulnerable bonds from enzymatic attack
- Use their hydrolytic enzymes to recycle the cell’s own organic material
Explain lysosome's function of phagocytosis?
- i. Forms food vacuole, which fuses with lysosome, whose enzymes digest the food
- ii. Macrophages also do this
Explain lysosome's function of autophagy?
- a. Damaged organelle or small amount of cytosol becomes surrounded by double membrane and lysosome fuses with outer membrane of this vesicle
- i. Enzymes dismantle the enclosed material, and make it available to the cytosol
__ can be caused by lack of functioning hydrolytic enzymes, causing them to become engorged with __, which interfere with __.
- indigestible substrates
- other cellular activities.
transfer membrane segments
1. Derived from __ and __
2. Selective in __, which causes what?
4. Some carry out __.
- ER/ Golgi apparatus
- transporting solutes
- solution inside differs in composition from cytosol
- Food and contractile
- enzymatic hydrolysis
Explain contractile vacuoles.
Pump excess water out of the cell, thereby maintaining a suitable concentration of ions and molecules inside the cell
Explain small vacuoles in plants.
- smaller vacuoles can hold reserves of important organic compounds.
- a) They can protect plant form herbivores by storing compounds that are poisonous or unpalatable to animals and contain pigments
Explain central vacuole in plants.
- a. Solution inside (cell sap) is plant cell’s main repository of inorganic ions
- b. Growth of plant cells, which enlarge as the vacuole absorbs water