2. Structure and Metabolism Flashcards
Process of reproduction by prokaryotes
Binary fission
Approx length of time of binary fission
Approx. 20 mins
Bacteria acquire nutrients from the environment through which type of transport?
Active transport
Requirements for all bacteria
- carbon source
- nitrogen source
- energy source (ATP)
- trace elements
Purpose of carbon source for bacteria
For cellular constituents
Purpose of nitrogen source for bacteria
For proteins
Purpose of energy source for bacteria
To perform cellular tasks
Trace elements required for all bacteria
Iron Calcium Zinc Copper Manganese Cobalt Phosphorus Sulphur Magnesium Potassium
Bacteria that lives and grows in air; cannot grow anaerobically
Obligate aerobe
Bacteria that grows aerobically and anaerobically
Facultative anaerobe
Bacteria that grows better anaerobically, but can tolerate low levels of O2
Aerotolerant anaerobe
Bacteria that only grows anaerobically, poisoned by O2
Obligate anaerobe
Bacteria that grows in environments where there is increased CO2 or other enrichments
Microaerophilic
Purpose of bacterial metabolism
Production of ATP
Process where glucose is converted into pyruvate
Fermentation
Other names for Fermentation
Embden-Meyerhoff pathway
Glycolysis
Metabolism in the absence of O2 (anaerobic)
Fermentation
Net gain in fermentation
2 ATP
NADH2
End products of Fermentation
Pyruvate
NADH
FADH
Metabolism under the presence of O2
Aerobic respiration
2 pathways in aerobic respiration
Krebs cycle (Tricarboxylic acid cycle) Electron transport chain
Fermentation product that enters the Krebs cycle/TCA
Pyruvate
Fermentation product(s) that enter the electron transport chain
NADH (Nicotinamide adenine dinucleotide)
FADH (Flavin adenine dinucleotide)
Net gain in Aerobic respiration
38 ATP (incl. ATP from fermentation)
End-products in aerobic respiration
CO2
H2O
Application of fermentation and respiration in the lab
Acid detection
Gas detection
Alcohol detection
General diameter and length of bacteria
0.2 - 2 um diameter
1 - 6 um length
Single, long, supercoiled, circular DNA molecule attached to the cell membrane; contains genetic info to code for products
Chromosome
Small, circular double-stranded DNA; may code for antibiotic resistance; can be exchanged between a donor and recipient during conjugation
Plasmids
Sites of protein synthesis
Ribosomes
A 70s prokaryotic ribosome comprises
A 30s subunit and a 50s subunit
Bacterial cell membrane consists of
Proteins
Phospholipids
Defines the shape of bacterial cells
Bacterial cell walls
Main constituent of bacterial cell walls; sugar molecules linked by small peptide chains
Peptidoglycan
True/False. Peptidoglycan can only be found in bacteria
True
Differentiate the cell walls of gram-negative and gram-positive bacteria
Gram-positive bacteria have thick layer of peptidoglycan
Gram-negative bacteria have much thinner peptidoglycan layer but they have lipopolysaccharide (LPS) inside the cell wall
Part of lipopolysaccharide that protrudes from cell surface
O antigen
A slimy, gelatinous material produced near the cell membrane and secreted outside of the cell wall
Glycocalyx
2 types of glycocalyx
Slime layer
Capsule
Bacteria that have a slime layer glycocalyx
Pseudomonas
Staphylococcous
Glycocalyx that is not highly organized nor firmly attached to the cell wall
Slime layer
Glycocalyx that is highly organized and is firmly attached to the cell wall
Capsule
Bacterial capsule is usually made up of what substance?
Polysaccharides which may combine with lipids and proteins
Function of capsule
Protects bacteria from engulfment by WBCs
Function of glycocalyx
Protects bacteria from antibiotics
Enables bacteria to move in liquid environment
Flagella
The flagella consists of
Three or more protein appendages twisted together
AKA pili
Fimbriae
True/false. Pili is associated with motility
False
Short, hairlike structures usually on external surface of gram-negative bacteria
Pili
2 types of pili
Adherence pili
Sex pili
Function of adherence pili
Anchors the bacteria to surfaces
Funtion of sex pili
Transfers genetic material
The cell possessing a sex pilus is called
Donor cell
What is transferred through the sex pilus?
Genetic material (usually a plasmid)
Function of spores
Means of survival when moisture or nutrients are low
Process of spore formation
Sporulation
2 bacterial genera that are spore-formers
Bacillus
Clostridium
Bacteria that cause disease are termed
Pathogenic
Examples of virulence factors
Exotoxins Endotoxins Capsules Pili Other extracellular proteins
Single-cell organisms lacking membrane-bound nuclei
Prokaryotes