________ microscope - minimum resolution is - 2 microns ( the size of a small bacterium) chapter 6 a...
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• ________ microscope -minimum resolution is - 2 microns ( the size of a small bacterium)
CHAPTER 6A TOUR OF THE CELL
For higher resolution--____________microscope-Transmission Electron Microscope-Scanning Electron Microscope
Microscopy
Fig. 6.2
• Prokaryotic vs eukaryotic cells
1. Prokaryotic and eukaryotic cells differ in size and complexity
•Similarities-
•A ___________________.
•A ________(semifluid substance) within the cell
•________________
•___________- organelles that make proteins
•Differences
•Euks have chromosomes in a _________(compared to a nucleosome in proks.)
•Euks have many _________ __________________
•Eukaryotic cells are ___________ times larger
• Larger organisms do not generally have______cells than smaller organisms - simply _______ cells.
Fig. 6.6 The prokaryotic cell is much simpler in structure, lacking a nucleus and the other membrane-enclosed organelles of the eukaryotic cell.
Prokaryote components
• The _________________- functions as a selective barrier that allows passage of oxygen, nutrients, and wastes for the whole volume of the cell.
Fig. 6.8
Animal cell
Animal cells lack:• ___________•___________•___________•___________
Fig. 6.9
Fig. 6.9
Plant cell
Plant cells lack:•__________•__________•__________
Most other components are ________ by plant and animal cells
• contains most of the _______ in a eukaryotic cell.
• Some genes are in _________________and _____________
• separated from the cytoplasm by a _________membrane.
• Protein pores allow large macromolecules and particles to pass through.
• ___________ (located internal to the membrane)- maintains nuclear _________
1. The ___________
Fig. 6.10
• ___________ (DNA and associated proteins)
• Each eukaryotic species has a characteristic number of ____________
• A typical human cell has 46 chromosomes, but sex cells (eggs and sperm) have only 23 chromosomes.
• ___________- densely stained fibers and granules adjoining chromatin
•Factory for ribosomal RNA (rRNA)
•rRNA is a component of _______________.
1. The nucleus (cont.)
Fig. 6.10
_________________-
• contain _______ (from nucleolus) and _________.
• composed of two subunits
• carry out _________ synthesis.
2. ________________ build a cell’s proteins
Fig. 6.11Ribosomes
• Found in ____locations-
• 1. ________ ribosomes -suspended in the cytosol
• Function: synthesize ___________ proteins
• 2__________ ribosomes- attached to the outside of the _____________________
• Function: synthesize __________ proteins and ____________ proteins
• Note: Ribosomes can shift locations.
Ribosomes- (cont.)
• Accounts for ½ the membranes in a eukaryotic cell.
• Includes membranous tubules and internal, fluid-filled spaces, the ________.
• The ER membrane is continuous with the ________________
3. The endoplasmic reticulum (ER)
• Function: Manufactures ____________
Fig. 6.12
• Two regions of ER that differ in structure and function.
• _________ ER
• lacks ribosomes
• Function: synthesize lipids, including oils, phospholipids, and steroids
• Also detoxifies drugs and poisons
• _________ ER
• ribosomes attached to the outside
• Packages proteins into _____________________
Fig. 6.12
The endoplasmic reticulum (cont.)
• Endoplasmic reticulum
• Ribosomes
• Nucleus
Review
• Function: Finishes, sorts, and ships _____________
• Many transport vesicles from the ER travel to the _______________________ for modification of their contents.
4. The Golgi apparatus
• structure contains __________ – looks like a stack of pita bread.
Cis face“receiving”
Trans face“shipping”
_____ face _______ vesicles from ER; ______ face ships vesicles out
Fig. 6.13
• a membrane-bounded sac of ___________ enzymes
• functions -digest ___________________ (proteins, fats, polysaccharides, and nucleic acids).
• Low pH (5.0)
5. _______________
Fig. 6.14a
•massive leakage from lysosomes can destroy an cell by ______________
Nucleus
Lysosome
5. Lysosomes (Cont.)
• The lysosomal enzymes and membrane are synthesized by __________ and then transferred to the ________.
• At least some lysosomes bud from the trans face of the Golgi.
Fig. 6.16
Inherited diseases affect_____________ metabolism:
• These individuals lack a functioning version of a normal hydrolytic enzyme.
• Result- Lysosomes are engorged with __________________ substrates.
• ____________disease in the liver
• Tay-Sachs disease in the brain.
• Lysosomes can fuse with ________________ or other organelles
5. Lysosomes (Cont.)
• Vesicles and vacuoles (larger versions) are membrane-bound ____ with varied functions.
• _____ vacuoles, from phagocytosis, fuse with lysosomes.
• ______________ vacuoles, found in freshwater protists, pump excess water out of the cell.
• ___________ vacuoles are found in many mature __________ cells.
• Functions - stockpiling proteins or inorganic ions, depositing metabolic byproducts, storing pigments, and storing defensive compounds against herbivores.
6. _____________
Fig. 6.15
• Convert energy to forms that cells can use for work.
• _____________ -site of __________ _____________, generating ATP from the catabolism of sugars, fats, and other fuels in the presence of oxygen.
• Chloroplasts, found in plants and eukaryotic algae, are the site of _________________.
• They convert solar energy to chemical energy and synthesize new organic compounds from CO2 and H2O.
7. ______________ and ________________
Chloroplast
Mitochondria
Fig. 6.17
Fig. 6.18
• Mitochondria and chloroplasts-
• Proteins from _____ ribosomes in the cytosol (and a few from their own ribosomes).
• Contain DNA
• Grow and reproduce as ________________ organelles.
• Almost all _____________ cells have mitochondria.
• Cells may contain one to ________________.
• The number of mitochondria is correlated with aerobic metabolic activity.
7. Mitochondria and Chloroplasts (Cont.)
• The chloroplast is a type of ______.
• ______plasts- store starch in roots and tubers.
• _______plasts- store pigments for fruits and flowers.
• _______plast- produces sugar via photosynthesis.
• Chloroplasts gain their color green pigment chlorophyll.
• The ______ in the chloroplast is separated from by two ___________.
• contains DNA, ribosomes, and enzymes for part of photosynthesis
.
7. Mitochondria and Chloroplasts (Cont.)
Fig. 6.18
• generate and degrade _________________ (H2O2) in performing various metabolic functions
• H2O2 is ______, but the peroxisome has another enzyme that converts H2O2 to water.
8. _______________
•Functions:
• break _____________ down for fuel.
•________ alcohol (and other harmful compounds).
•Convert the fatty acids in seeds to sugars
Fig. 6.9
• The _________________ is a network of_______ extending throughout the cytoplasm.
• Functions:
• Organizes the structures and
activities of the cell.
• Provides _________________ support and maintains shape of the cell.
• Provides______________ for many organelles and cytosolic enzymes
• dynamic
9. Cytoskeleton
Fig. 6.20
• There are three main types of fibers in the cytoskeleton:
• _______________
• ________________
• ___________________.
9. Cytoskeleton (Cont.)
Fig. 7.21b
microfilaments
Intermediate filaments
(Keratin)
(Actin)
Fig. 6.26
Function in plants: protection, maintains its shape, and prevents excessive uptake of water.
• It also supports the plant against the force of gravity.
10. Cell wall – Plant and proks, but not _________ cells
• Composed of microfibrils of _______ embedded in a matrix of proteins and other polysaccharides.
•steel-reinforced concrete analogy
Fig. 6.28
• Can influence the activity of genes in the nucleus via a combination of chemical and mechanical signaling pathways.
• This may coordinate all the cells within a tissue.
• Function- support, adhesion, movement, and regulation
• Animals cells have an elaborate _____.
• _______ fibers embedded in a network of __________.
• The_________ connect the ECM to the ________.
11. The _____________________ (ECM)
Fig. 6.29
• Function- Cell to cell communication and cell-cell contact
• Plant cells are perforated with ____________________, channels allowing cysotol to pass between cells.
12. _______________________
Not in text