Chapter 3 Video Notes

Question 1

Describe four major properties of living cells.

Answer 1

-growth: living things can grow/increase in size

-reproduction: organisms can increase in #, reproduce a/sexually

-responsiveness: living things respond to their environment, change themselves in reaction, & have taxis

-metabolism: the ability to take in nutrients from outside themselves & use the nutrients in a series of controlled chemical reactions to provide the energy & structure needed to grow, reproduce, & be responsive

Question 2

What are the Three domains of life?

Answer 2

Archaea, Bacteria, Eukaryua

Prokaryotic Cells
Archea
Bacteria

Eukaryotic Cells
Eukaryua

Question 3

What are prokaryotic cells?

Answer 3

Include bacteria and Archea.
Unicellular
Has a simple structure,
lacks membrane-bound nucleus
Lacks membrane-bound organelles
Are typically 1 um in diameter or smaller

Question 4

What are Eukaryotic cells?

Answer 4

Includes fungi, Protozoa, animals, plants, and helminths.
Unicellular and multicellular
Have membrane-bound nucleus
Have membrane-bound organelles.
10-100 um in size

Question 5

What do all cells have in common?

Answer 5

Cytoplasmic membrane
cytoplasm
ribosomes
Chromosomes/ genetic material

Question 6

What is a Pathogen?

Answer 6

Microorganisms are capable of causing disease.

Question 7

What is Pathogenicity?

Answer 7

A microorganism’s ability to cause disease.

Question 8

What is Virulence?

Answer 8

A measure of pathogenicity

Question 9

What is Disease?

Answer 9

Any condition in which normal structures or functions of the body are damaged or impaired.

Question 10

What are Virulence Factors?

Answer 10

Enzymes, toxins, and other factors affect the relative ability of a pathogen to infect or cause disease.

Question 11

What are the external structures of bacteria cells?

Answer 11

Flagella
Pili
Glycocalyx
Fimbriae

Question 12

What is Glycocalyx?

Answer 12

Is a sugar coating surrounding the outside of the cell

Location - Outside to the cell wall

Composed of polysaccharides, polypeptides, or both.

Question 13

What are the two types of Glycocalyx?

Answer 13

Capsule
-Composed of organized repeating units of organic chemicals
-Firmly attached to the cell surface

slime layer
-Loosely attached to the cell surface
-water-soluble

Question 14

What are Biofilms?

Answer 14

Biofilms aggregate of many bacteria that are living together on the surface.

Question 15

Capsulated bacteria vs encapsulated bacteria

Answer 15

Capsulated
-It has the presence of a capsule
- Able to cause disease
- Avoid destruction by the body cell defense
-Pathegeic
-Virulent
- ex Streptococcus pneumonia

Unencapsulated
- It has an absence of capsule
- not able to cause disease
-the body’s defense cell destroy them
-nonpathogenic
-Avirulent
- ex Streptococcus pneumonia

Question 16

What is Flagella?

Answer 16

Long structure that extends beyond cell surface.
Are not present on all bacteria
Are responsible for movement/ motility
Rotation propels them through environment

Question 17

What are the two types of taxis?

Answer 17

Phototaxis - move in response to light
chemotaxis - move in response to chemicals.

Question 18

What are the Three Types of flagella?

Answer 18

Pertrichous- Dispersed randomly all over the structure of the cell.
Polar- are only at the ends of the flagella
Endo flagella - from an axial filament that wraps around the cell.

Question 19

What is Fimrae?

Answer 19

Small, sticky, bristlelike projections

used by bacteria to adhere to one another and to substances in environment

There may be hundreds of fimbriae per cell

Shorter than flagella

Question 20

What is a pili?

Answer 20

-A special type of fimbriae
-Also known as conjunction pilus
-Longer than fimbriae but shorter than flagella
-In Bacteria that normally have one or two cells
-Used during mating/ conjunction
-Transfer DNA from one cell to the other.

Question 21

What is a cell wall and its three basic shapes?

Answer 21

The cell wall Provides the structure and shape of bacteria cells.

The Three shapes
Bacillus - Rod shape
Coccus - circle shape
Spiral- Spirillum , spirochete,
virbrio.

Question 22

Arrangements of cell shapes.

Answer 22

Staphylo = Clusters
Sterpto= chains

Question 23

Simple stain technique.

Answer 23

Simple stains
- Use one dye
-used to determine shape and size

Basic dyes
- dye is positively charged
-attracted to the negatively charged cell surface.
- Result cells appear the color of dye
- ex methylene blue

Question 24

What are Gram-positive cell walls?

Answer 24

-A relatively thick layer of peptidoglycan
-Contain unique poly alcohols call teichoic acids
- Appear purple after gram staining.

Question 25

What are teichoic acids?

Answer 25

• Stabilize peptidoglycan by increasing rigidity.
• Give gram-positive and negative charge.
  -Play a role in the passage of ions through the wall.

Question 26

What is a Gram-Negative bacterial cell wall?

Answer 26

• Have only a thin layer of peptidoglycan
• Has phospholipid bilayer
• Has Lipopolysachrides
• Contains lipid A
  -Appear pink after Gram staining
• protect against lysozyme

Question 27

What is the structure of the cytoplasmic membrane?

Answer 27

• Referred to as phospholipid bilayer
  -composed of lipids and associated proteins
• internal proteins and peripheral proteins
  -These proteins may act as recognition proteins, enzymes, receptors, carrier proteins, and channel proteins.

Question 28

What is the function of the bacterial cytoplasmic membrane?

Answer 28

• Control the passage of substances into and out of the cell
• Nutrients are brought into the cell, and waste is removed

-Selective permeability

• Allows some substances to cross while preventing others to cross

-Enable the cell to concentrate chemicals on one side of the membrane or the other.

Question 29

What is the structure of cytosol in bacteria?

Answer 29

-Present in all cells
-liquid portion of cytoplasm
-Mostly water
-contains cells DNA in region called nucleoid

Question 30

What’s an endospore?

Answer 30

• Some genera of bacteria can form bacterial spores called endospores.
  -Metabolically inactive structures that allow certain cells to enter a dormant state.
  -Highly resistant to environmental stress
  -serious concern to food processors, health care professionals, and governments.
• not reproductive

Question 31

How are they created?

Answer 31

• by bacillus or clostridum
  ex anthrax