• ________ 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