BACTERIA CH 4 Flashcards
Identify the structures common to all bacterial cells
Cell Membrane
Ribosomes
Cytoplasm
DNA (in the nucleoid region)
Identify 4 (/6) structures present in some bacteria
Cell Wall
Capsule
Pilus
Plasmid
Fimbriae
Flagella
CC, PP, FF
Identify the following structures and select which are present in all bacterial cells
A - Fimbriae
B - Cytoplasm*
C - DNA in Nucleoid*
D - Plasmid
E - Ribosomes*
F - Flagella
G - Pilus
H - Capsule
I - Cell Wall
J - Cell Membrane*
*Present in all Bacterial Cells
Identify and describe the general shapes of bacteria
Coccus - Circles
Bacillus - Rods
Vibrio - Any curve
Describe the general arrangements of cocci
Describe the general arrangements of bacilli
T/F Bacterial Fimbriae are used for conjugation
False; they are used to attach or hold onto things
Pili are used for conjugation
Capsules vs Biofilm
Capsules surround a single cell and is used as protection against phagocytosis
Biofilm surrounds entire cell communities
Function of Flagella
Long tail-like appendages that allow for true motility, and in some cases, attatchment
Function of Axial Fillaments
Inching Motion
Function of Fimbriae
Attatchment + Holding onto other cells (strep throat remaining in our pharynx)
Function of Pili
Attatchment from one bacteria to another; allows for the exchange of DNA from the plasmid
“bacterial sex”
Identify and describe the two types of chemotaxis
Positive Chemotaxis - Movement toward a favorable chemical stimulus
Negative Chemotaxis - Movement away from a potentially harmful chemical stimulus
You successfully complete a gram stain and all of your bacteria are pink. What does this tell about the structure of the bacterial species
GRAM-
Outer Membrane
Thin Peptidoglycan Layer (Cell Wall)
Inner Membrane
Describe Gram- Bacteria
Pink
Outer Membrane
Thin Peptidoglycan Layer (Cell Wall)
Inner Membrane
Describe Gram+ Bacteria
Purple
Thick Peptidoglycan Layer (Cell Wall)
Cell Membrane
Describe the gram stain procedure + Purpose + What the cells look like at each (major) step
- Place cells on a slide and let dry
- When dry, heat fix
- Add Crystal Violet Dye (Both cells purple)
- Add Grams Iodine (mordant sticks the dye to G+ cells; both purple)
- Alcohol (rinses away crystal violet in G- cells; G+ Purple, G- Clear)
- Add Safranin (G+ Purple, G- Pink)
How do Antibiotics work?
They work by targetting the peptidoglycan layer in bacteria (or 70s ribosomes);
- This mainly effects G+ Bacteria because they have a thick and exposed peptidoglycan layer
- This is not as effective in G- cells because they have porin proteins that can send the antibiotic in the opposite direction
Which type of bacterial infections are most difficult to treat?
Gram-
How does the outer membrane of gram- bacteria contribute to disease symptoms
Gram- Bacteria have an outer cell membrane that contains lipopolysaccharides (LPS) that can lead to fever and shock reactions
How do Porin Proteins contribute to disease
They are found in the outer cell membrane of G- bacteria. Antibiotics work by targeting peptidoglycan but the porin proteins have the ability to send the antibiotics in the opposite direction stopping the effectiveness of the drug
How do Lipopolysaccharide contribute to disease
Found on the outer cell membrane of G- bacteria. When the bacterial cell is killed, lipopolysaccharides enter the bloodstream. Our body is then led to believe that we have a systemic infection and when we try to fight it we get high fevers, our blood volume drops, and we have shock reactions
T/F: Plasmids are vital to the metabolism of bacterial cells
False; plasmids contain genes that are considered “nice to have” but are NOT NECESSARY; superpowers
What is the function of cytoplasm?
Suspend organelles within the cell
