Chapter 4

Question 1

Eukaryotic Cell

Answer 1

Nucleus:	Present
Cell Type:Usually multicellular
True Membrane bound Nucleus:	Present
DNA wrapping on proteins:	packed with histones.
Ribosomes: larger

Question 2

Prokaryotic Cell

Answer 2

Nucleus: Absent
Cell Type: Usually unicellular
True Membrane bound Nucleus: Absent
DNA wrapping on proteins:Multiple proteins act together to fold and condense prokaryotic DNA

Question 3

What cells contain peptidoglycan?

Answer 3

Bacterial cell walls are made up of peptidoglycan

Question 4

What makes up the cell walls of organisms which do not contain peptidoglycan?

Answer 4

Many eurkaryotes have cell walls made of cellulose (all plants and some algae), the cell wall in most fungi is made of chitin, yeasts use glucan and mannan. Other eukaryotes use a glycocalyx as its most outer covering.

Question 5

What is peptidoglycan anyway?

Answer 5

Peptidoglycan consists of a repeating disaccharide attached by polypeptides to form a lattice that surrounds and protects the entire cell.

Question 6

What stain identifies cell wall differences in organisms which do contain peptidoglycan and why is it clinically (medically) important?

How does this stain work?

Answer 6

The Gram Stain.

The detection of gram negative bacteria has profound consequences on treatment methods. This is due to the fact that gram negative bacteria have a strong negative charge on their outer membrane, which helps them evade phagocytosis and lysing.

Question 7

the organisms?

Answer 7

Prokaryotes are able to grow faster in number versus eukaryotes.

Question 8

What are the names and functions of the various types of glycocalyx?

Answer 8

Glycocalyx (meaning sugar coat) is the general term for substances that surround cells.

Bacterial glycocalyx can be composed of polysaccharide, polypeptide, or both.

Question 9

What cells possess glycocalyx?

Answer 9

Both prokaryotic and eukaryotic cells.

Question 10

What are flagella?

Answer 10

Long filamentous appendages that propel the cell.

Question 11

How does flagella differ between prokaryotic and eukaryotic cells?

Answer 11

Prokaryotic flagella rotate while eukaryotic flagella move in a wavelike manner.

Question 12

How can flagella be arranged on a cell?

Answer 12

Atrichous (without flagella)
Peritrichous (distributed over the entire cell)
polar (at one or both ends of the cell).

If polar, flagella may be monotrichous (a single flagellum at one pole), lophotrichous (a tuft of flagella coming from one pole), or amphitrichous (flagella at both ends of the cell).

Question 13

How do axial filaments differ?

Answer 13

Axial filaments are bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around the cell.

Question 14

How are flagella and axial filaments beneficial to cells?

Answer 14

It allows the cell to move in response to stimulus, presence or absence of food

Question 15

What are pili? What are their functions?

Answer 15

Appendages on a bacterial cell used for conjugation and gliding motility

Question 16

What differences exist between Gram positive and Gram negative cell walls?

Answer 16

Gram positive = thick layer of peptidoglycan

gram negative = thin layer of peptidoglycan along with the presence of lipopolysaccharides, lipoproteins, and phospholipids.

Question 17

What sorts of transport can cells use to move substances across the membrane, how do they differ?

Answer 17

Two kinds of processes: passive and active

In passive, substances cross the membrane from an area of high concentration to an area of low concentration.

In ACTIVE processes, the cell must use energy (ATP) to move substances from areas of low concentration to high concentration, against the gradient.

Question 18

What is osmolarity?

Answer 18

The concentration of a solution expressed as the total number of solute particles per liter

Question 19

How does osmolarity affect cells?

Answer 19

Cell survival depends on balancing water uptake and loss. Cells can burst if they take on too much water, or collapse if they lose too much.

Question 20

What are inclusions?

Answer 20

Material held inside of a cell consisting of reserve deposits.

Question 21

What features of bacterial DNA are unique and where is it found in a cell?

Answer 21

Bacterial DNA is in one circular chromosome and lacks histones for packaging. It is located within the cytoplasm freely. In eukaryotic cells the DNA is packaged with histones and sequestered within a nucleus.

Question 22

What are ribosomes, how do they differ between cell types and where are they located?

Answer 22

Ribosomes are the sites of protein synthesis. In prokaryotes, the ribosomes are smaller in size and located within the cytoplasm.

Question 23

What are endospores?

Answer 23

? Endospores are specialized resting cells that bacteria can form when nutrients are depleted.

Question 24

What cells are capable of making endospores?

How and for what purpose?

Answer 24

Clostridium and Bacillus bacteria.

To ensure survival and reactivate when nutrients are again plentiful.

Question 25

How do plasma membranes differ between prokaryotes and eukaryotes?

Answer 25

The plasma membrane or prokaryotes consists primarily of phospholipids, which are the most abundant chemicals in the membrane, and proteins.

Eukaryotic plasma membranes also contain carbohydrates and sterols, such as cholesterol

Question 26

What are organelles and what are the functions of the specific organelles discussed in class?

What cells possess them?

Answer 26

Eukaryotic cells possess organelles. Organelles are structures with specific shape and specialized functions.

Question 27

What is the endosymbiotic theory?

What evidence supports it (generally and specifically)?

Answer 27

Endosymbiotic theory is a model for the evolution of eukaryotes which states that organelles arose from prokaryotic cells living inside a host prokaryote.

Larger bacterial cells lost their cell walls and engulfed smaller bacterial cells.