Lecture 7

Question 1

Where is the cell membrane situated?

Answer 1

Beneath the cell wall

Question 2

What is another term for the cell membrane?

Answer 2

Cytoplasmic membrane

Question 3

True or false. When using an electron micrograph, the cell membranes appear as a double layer, which is true to form for all cells.

Answer 3

True.

Question 4

How thick is a cell membrane?

Answer 4

5-8 nm thick.

Question 5

Explain the concept of permeases.

Answer 5

Permeases is the transport of specific substances across the cell’s membrane.

Question 6

Define invaginated.

Answer 6

Invaginated means to to insert or receive- in this context- the membrane received numerous activities.

Question 7

True or false. The cell membrane does not have implication in cell division.

Answer 7

False.

Question 8

True or false. The cell membrane consists of a bilayer of phospholipids molecules in which are embedded the proteins.

Answer 8

True

Question 9

True or false. Capsules are thin.

Answer 9

False. Capsules are thick and vary in thickness.

Question 10

Describe the appearance of the capsule.

Answer 10

They are thick, viscous, jelly like structures that surround the cells of species.

Question 11

True or false. Slime lacks form or specific shape.

Answer 11

True

Question 12

What do capsule and slime provide to the cell?

Answer 12

Adherence to the cell, protect bacterial cells against dehydration, protection against phagocytosis.

Question 13

Where does the flagella originate from in the cell?

Answer 13

Cytoplasm and protrude from the cell wall (like sperm)é

Question 14

What is the function of the flagella?

Answer 14

They allow bacteria to be motile, they are organelle of locomotion.

Question 15

Name a few flagella that are not motile.

Answer 15

Spirochetes and gliding bateria.

Question 16

What type of movement does the flagella moves in?

Answer 16

Rotating like a propeller-which is why a cell rotate as well.

Question 17

What type of microscope permits you to visualize a flagella and why is this measure needed.

Answer 17

An electron microscope considering that they are not visible though a light microscope due to their small size.

Question 18

What is the single protein called which forms a flagella?

Answer 18

Flagellin.

Question 19

Name the composition of a eucaryotic flagella.

Answer 19

Made of 9 pairs of protein fibres wrapped around 2 two fibres named microtubules. They move in a whiplike fashion.

Question 20

Name the two types of flagella that a bacteria cell may posses and define them with an example of species.

Answer 20

Polar flagella- attached at one end of the cell. ex: Pseudomonas, Spirilllus and Vibros.
Peritrichous flagella- attacher at many areas of the cell. ex: enterobacteriaceas such as salmonella, proteus, bacillus and Escherichia.

Question 21

True or false, Fimbriae are smaller than flagellas. Elaborate.

Answer 21

True. They are thinner, shorter, straight, and more numerous than flagellas.

Question 22

What is the main function of the fimbriae?

Answer 22

They permit bacteria to stick to surfaces.

Question 23

Fimbriae occur on the surface of what type of bacteria?

Answer 23

Gram-negative and few Gram-positive.

Question 24

Fimbration is common among with species?

Answer 24

The bacteria Enterobacteriaceae.

Question 25

True or false, pili are smaller than fimbriae.

Answer 25

False, they are longer and similar in structure.

Question 26

True or false. Pili cover the cell

Answer 26

False. Only few pili cover the cell.

Question 27

What is the main function of the pili?

Answer 27

They are responsible for the mating process named conjugation of the cells.

Question 28

True or false. Bacterial viruses attach to the bacterial cell by attaching to the pilus.

Answer 28

True.

Question 29

Name the three materials enclosed in the cell membrane.

Answer 29

1-The nucleic which is DNA 2-Cytoplasmic area which is rich in RNA 3-Fluid which is rich in nutriments

Question 30

Explain the composition of RNA.

Answer 30

RNA is a mix of protein known as ribosomes which are packed through the cytoplasmic.

Question 31

Ribosomes is the site of which synthesis?

Answer 31

Ribosomes is the site of protein synthesis.

Question 32

In addition, what four types of granules do some bacteria posses?

Answer 32

1-Polysaccharide granules 2-Poly-beta-hydroxybutyric acid granules 3-Volutin granules 4-Sulfur granules

Question 33

Which two types of granules provide intracellular sure of carbon or energy?

Answer 33

Polysaccharides granules and Poly-beta-hydroxybutyric acid granules. Organic materials.

Question 34

What are polysaccharide granules also named?

Answer 34

Glycogen granules

Question 35

What are volition granules also names? And what do they reserve?

Answer 35

Metachromatic granules. Inorganic phosphate.

Question 36

What does the term spore signify?

Answer 36

That the spore is formed within the cell.

Question 37

Describe what the spores body is resistant to.

Answer 37

Heat, desiccation, toxic chemicals and electromagnetic radiation.

Question 38

What type of shape are the spores?

Answer 38

They are spherical and ellipsoidal.

Question 39

What causes the cell to swell when we are referring to the spore.

Answer 39

the spore is larger in diameter than the cell's diameter causing the cell to swell.

Question 40

What three positions do the spores adopt in the cell?

Answer 40

1-Central (center) 2-Subterminal (more to the right) 3-Terminal (elongated and to the far right)

Question 41

Name the eight genera of endospore- forming bacteria.

Answer 41

``` 1-Bacillius - anaerobic rods 2-Clostridium- anaerobic rods 3-Sporolactobacillus 4-Sporosarcina 5-Desulfotomaculum 6-Sporomusa 7-Sporohalobacter 8-Anaerobacter ```

Question 42

Describe the life cycle of an endospore.

Answer 42

Vegetative cell- endospore-spore-vegetative cell.

Question 43

What temperature are endospores killed at and with what instrument?

Answer 43

Autoclave at 121 degrees celsius.

Question 44

True or false. Endospores are very visible using a bright field microscope.

Answer 44

True.

Question 45

True or false. Spore is not resistant to staining due to the impermeability of the outer layer.

Answer 45

False. The spore is quite resistant to staining.

Question 46

What is not necessarily a characteristic of bacterial endospores?

Answer 46

Causes swelling of the vegetative cell