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
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 __.
separates it from contents of cytoplasm
lines each pore and plays role in regulating entry and exit of proteins and RNAs and macromolecules
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
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
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?
1. More than half the__ in eukaryotic cells
2. Consists of membranous tubules and sacs called __
3. Speratares the __ from the __
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
sorted and targeted
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
i.Lysosomes 1.__environments 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 __?
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 __.
other cellular activities.
transfer membrane segments
1. Derived from __ and __
2. Selective in __, which causes what?
4. Some carry out __.
ER/ Golgi apparatus
solution inside differs in composition from cytosol
Food and contractile
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