Prokaryotes: Bacteria 09/04/18

Question 1

What are the two types of Prokaryotes?

Answer 1

Bacteria and Archaea

Question 2

What are the two main differences between Bacteria and Archaea?

Answer 2

1. How they package their DNA

2. How they contain their internal structures

Question 3

What are the two most common forms of bacteria?

Answer 3

1. Coccus (sphere shape)

2. Bacillus (rod shape)

Question 4

What are the less common forms of bacteria?

Answer 4

1. Coccobacillus
2. vibrio
3. spiralla
4. spirochete
5. pleomorphic

Question 5

What are the terms for a coccus pair? A chain? A cluster?

Answer 5

Pair- diplo
chain- strep
cluster- staph

Question 6

What are the terms for a bacillus pair? A chain? A cluster?

Answer 6

Pair- diplo
Chain- Strep
Cluster- Palisades

Question 7

What are the layers of the bacterial cell envelope?

Answer 7

1. capsule or slime layer (outermost)
2. Cell wall (middle)
3. Plasma membrane (innermost)

Question 8

What are the types of proteins found in the plasma membrane (Cell envelope)?

Answer 8

1. Integral proteins

2. peripheral proteins

Question 9

Give a brief description on integral proteins.

Answer 9

embedded in membrane, insoluble

Question 10

Give a brief description on peripheral proteins.

Answer 10

Loosely connected to membrane, soluble

Question 11

What are the jobs of integral proteins?

Answer 11

A. Transportation in and out of the cell
B. Energy processes: ETC
C. Interact with environment

Question 12

How does temperature affect membrane fluidity?

Answer 12

Warmer temps increase fluidity; colder temps decrease fluidity

Question 13

More _________ fatty acid portion of phospholipid maintains fluidity in cold temp by preventing tight packing in bilayer

Answer 13

Unsaturated

Question 14

Microbes that prefer high temps are?

Answer 14

Longer and more saturated

Question 15

Microbes that prefer lower temperatures are?

Answer 15

shorter and unsaturated

Question 16

**How does the membrane transport “things” in and out of the cell?

Answer 16

the membrane is selectively permeable (know this)

Question 17

What are the types of transport?

Answer 17

A. Passive
B. Facilitated
C. Active
D. Group translocation
E. Iron intake

Question 18

a) What are main features of passive transport (diffusion)?

b) What types of molecules can undergo passive transport?

Answer 18

A. Molecules move based on concentration gradient at a rate based upon the difference between the concentrations
B. Only gases and non-charged molecules

Question 19

What are main features of Facilitated diffusion?

Answer 19

A. Molecules move with assistance from transport proteins.
B. Channel proteins, Carrier (Uniport) proteins, very specific
C. Still diffusion which means no energy

Question 20

What is the main feature(s) of active transport?

Answer 20

Uses energy to transport molecules against the gradient.

Question 21

What is the difference between primary active transport and secondary active transport?

Answer 21

Primary active transport uses ATP to move molecules

Secondary active transport uses energy from ION down gradient

Question 22

What is the function of Antiporters?

Answer 22

one molecule moves out while another molecule comes in

Question 23

What is the function of Symporters

Answer 23

two different molecules move in the same direction

Question 24

a) What are the main features of Group translocation?

b) What type of transport is it considered?

Answer 24

A. molecule is chemically modified when moved into the cell by carrier proteins
B.active transport
An example of this would be E. Coli which transports sugars like glucose, fructose, mannitol, sucrose.
This creates a one-way street

Question 25

What is the main feature of Iron uptake?

Answer 25

Extermely important for bacteria, but iron is not very soluble so very little available.

Question 26

What are Siderophores and what is their role in Iron uptake?

Answer 26

They are molecules released by bacteria, bind iron, and bring it back to the cell to be released or use ABC transporter

Question 27

What are the jobs of the cell wall?

Answer 27

A. Maintains Cell shape B. protection from lysis(rupturing of the cell) C. protection from toxic substances D. contributes to pathogenicity (causing disease in humans) **The cell wall is the target of many antibiotics

Question 28

What happens when the osmotic pressure inside the cell is less than the outside?

Answer 28

It would be a hypertonic solution and the cell would undergo Plasmolysis

Question 29

What happens when the solution inside the cell has more osmotic pressure than the outside?

Answer 29

It would be a hypotonic solution and the cell would undergo Osmotic lysis (rupture of the cell)

Question 30

What happens when the osmotic pressure inside the cell is equal to the pressure outside the cell

Answer 30

It would be an isotonic solution and nothing would happen

Question 31

What is peptidoglycan? (In the cell wall) | What subunits are found in it?

Answer 31

Mesh like structure found in all bacterial cell walls; consists of repeating subunits: NAG, NAM, & oligopeptides - they are strong, elastic, porous - **penicillin targets this structure

Question 32

What are lipopolysaccharides and where are they found? | In the cell wall

Answer 32

They are only found in gram negative bacteria. - Consists of three parts: O-antigen, core polysaccharide, Lipid A - Protects bacteria from host defenses and acts as a potent endotoxin - When released, causes septic shock

Question 33

What are Porins and where are they found? (In the cell wall)

Answer 33

Found in only gram negative bacteria - form channels across cell wall - allows small molecules to enter the periplasm

Question 34

What is Teichoic Acid and where is it found? (In cell wall)

Answer 34

Found only in gram POSITIVE bacteria | -aid in cell shape, division, and antimicrobial resistance

Question 35

How to identify Gram positive and negative

Answer 35

``` Positive is purple; negative is pink Step 1 = crystal violet (Primary stain) Step 2 = Iodine (Mordant) Step 3 = Alcohol (de-colorizer) Step 4 = Safranin (Counterstain) ```

Question 36

What are the similarities between gram positive and gram negative? *******

Answer 36

A. Periphrastic Space B. PPG C. Plasma membrane

Question 37

What are some things that gram positive feature that gram negative doesn't?

Answer 37

Teichoic Acid, Exotoxins, Antibiotic susceptible

Question 38

What are some things that gram negative feature that gram positve doesn't?

Answer 38

Outer membranes - LPS - Porins - Endotoxins - Antibiotic resistant