Module 2 - Cell Structure & Function, Microscopy, + Prokaryotes/Eukaryotes

Question 1

What are the different types of microscopy?

Answer 1

Light microscopy and electron microscopy

Question 2

How many colors and dyes does Simple Stains use? How about differential stains?

Answer 2

1) Simple stains - 1 color, 1 dye
2) Differential stains - 2 colors, 2 dyes

Question 3

What kind of shapes are revealed in Gram morphology?

Answer 3

1) Cocci
2) Rod (bacilli)
3) Vibrio
4) Spirilia
5) Spirochete

Question 4

Compare Gram-positive and Gram-negative bacteria: peptidoglycan layer.

Answer 4

• Gram positive = thick (mutilayered)
• Gram-negative = think (single-layered)

Question 5

Compare Gram-positive and Gram-negative bacteria: teichoic acids.

Answer 5

• Gram positive = present in many
• Gram-negative = absent

Question 6

Compare Gram-positive and Gram-negative bacteria: periplasmic space.

Answer 6

• Gram positive = granular layer
• Gram-negative = periplasm

Question 7

Compare Gram-positive and Gram-negative bacteria: outer membrane.

Answer 7

• Gram positive = absent
• Gram-negative = present

Question 8

Compare Gram-positive and Gram-negative bacteria: lipopolysaccharide (LPS) content.

Answer 8

• Gram positive = none
• Gram-negative = high

Question 9

True or False: The cell membrane of both Gram-positive and Gram-negative bacteria is different.

Answer 9

FALSE - The cell membrane of both Gram-positive and Gram-negative bacteria is the SAME.

Question 10

What are antibodies?

Answer 10

Proteins produced by the human immune system in response to infection

Question 11

What are the two types of electron microscopy?

Answer 11

1) TEM - reveals inside detail
2) SEM - surface electron microscopy

Question 12

Are bacteria prokaryotes or eukaryotes? What about human cells?

Answer 12

Bacteria are prokaryotes, and human cells are eukaryotes

Question 13

What similarities do prokaryotic and eukaryotic cells share?

Answer 13

1) Both are made of similar polymers
2) Both carry similar chemical reactions
3) Both have a ribosome, but of different sizes
4) Both may or may not have a cell wall
5) Both have a similar cell membrane

Question 14

What differences do prokaryotic and eukaryotic cells share?

Answer 14

1) Prokaryotic cells lack membrane-enclosed organelles (mitochondria, chloroplasts, Golgi apparatus, etc.), including a nucleus
2) Peptidoglycan is found only in prokaryotes
3) Endospores are found only in prokaryotes

Question 15

True or False: Every cell has flagella and pili, but not every cell has a cell membrane

Answer 15

FALSE - Not every cell has flagella and pili, but EVERY cell has a cell membrane

Question 16

What is contained in the cell envelope?

Answer 16

Outer membrane - cell wall and cytoplasmic membrane

Question 17

What is the hallmark of the cell?

Answer 17

Cell membrane - controls what the cell is all about

Question 18

What does the cell membrane do?

Answer 18

Regulates what goes in and out of the cell

Question 19

What organelle IS present in both eukaryotes and prokaryotes?

Answer 19

Ribosomes

Question 20

What is the function of ribosomes?

Answer 20

Protein synthesis

Question 21

What is the function of the periplasmic space?

Answer 21

Contains hydrolytic enzymes and binding proteins for nutrient processing and uptake

Question 22

What is the function of the cell wall?

Answer 22

Gives prokaryotes shape and protection from osmotic stress

Question 23

True or False: Chromosomes (DNA) are a MUST-HAVE for both prokaryotes and eukaryotes.

Answer 23

True

Question 24

What are the layers of the cell wall of a Gram-positive and Gram-negative bacterium made of?

Answer 24

N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), but has more peptidoglycan. To clarify, these layers (NAG and NAM) make up the peptidoglycan cell wall.

Question 25

What are porin proteins, and which type of Gram bacteria are they present in?

Answer 25

1) Porin proteins = channels through which things go in and out, and can be restrictive 2) Gram-negative

Question 26

True or False: Gram-negative bacteria are more resistant to chemicals than Gram-positive bacteria because of porins

Answer 26

True

Question 27

What is unique about the cell wall of a Gram (-) bacteria?

Answer 27

It has an outer membrane, which adds another layer of protection. It also contains several factors, like LPS

Question 28

What does LPS stand for, and what does it contain?

Answer 28

1) LPS = lipopolysaccharide 2) Contains lipid A, which the toxis portion of LPS that causes a lot of diseases

Question 29

What is the cell membrane made of?

Answer 29

Made of phospholipids

Question 30

The cell membrane contains a _________ ______________ membrane.

Answer 30

lipid bilayer

Question 31

The lipid bilayer membrane in the cell membrane contains phospholipids which have ___________ and ___________ areas.

Answer 31

Hydrophobic (tail) and hydrophilic (head)

Question 32

What allows the movement of lipids and proteins?

Answer 32

The fluid-mosaic model

Question 33

What does selective permeability in the plasma membrane do?

Answer 33

Restricts the movement of material across the membrane, thus controls and regulate movement of materials and nutrients/waste in and out of the cell membrane

Question 34

What are glycolipids and glycoproteins?

Answer 34

Sugar molecules that attach either to a lipid or protein, and are important receptors

Question 35

What are peripheral proteins?

Answer 35

Loosely associated with the membrane and easily removed

Question 36

What are integral proteins?

Answer 36

Embedded within the membrane and not easily removed

Question 37

The ________ ___________ encompasses the cytoplasm

Answer 37

Plasma membrane

Question 38

True or False: The prokaryotic cell membrane is the location of crucial metabolic processes.

Answer 38

True

Question 39

Describe the cell wall of bacteria

Answer 39

A rigid structure that lies just outside the plasma membrane and provides a characteristic shape to the cell, as well as protects the cell from osmotic lysis

Question 40

What breaks the bond between NAG in the cell wall?

Answer 40

Lysozyme

Question 41

The cell membrane provides protection from what?

Answer 41

Osmotic pressure

Question 42

What are examples of layers of material lying outside the cell wall protecting it against harsh environments/chemicals?

Answer 42

1) Glycocalyx 2) Capsules 3) Slime layers 4) S-layers

Question 43

What is glycocalyx

Answer 43

The network of polysaccharides extending from the surface of the cell

Question 44

What are pili and fimbriae?

Answer 44

"Hair-like" structures that act like attachment devices that help bacteria attach to surfaces

Question 45

What is Horizontal Gene Transfer?

Answer 45

The exchange of genetic material between bacteria

Question 46

What functions are fimbriae responsible for? What about pili?

Answer 46

Fimbriae - Attachment and motility Pili - Attachment, motility, and genetic exchange

Question 47

How does a flagellum rotate?

Answer 47

Rotates like a propeller

Question 48

True or False: Both prokaryotes and eukaryotes have flagella

Answer 48

TRUE

Question 49

What are bacterial endospores?

Answer 49

Dormant structures that are resistant to numerous environmental conditions, such as heat, radiation, and chemicals

Question 50

What is the life stage of bacterial endospores?

Answer 50

1) Vegetative stage - living stage where bacteria are active and multiply 2) Sporulation - stage where it's turning into a spore 3) Germination - leaves the spore and goes back to the vegetative stage

Question 51

What is the concept of Ligand-Receptor?

Answer 51

"Life is based on the universal principle of the specific interaction of molecules with each other. Interacting molecules interact as pairs called LIGAND and RECEPTOR."