del 2 Flashcards
Transport of the substances to the cell:
a. The most frequently transport process for various substances to bacterias cell is pinocytosis.
b. Transport mechanisms and energy are imp during the group translocation.
c. The transporters are mainly of lipid origin.
d. Potentiated (mediated) diffusion occurs without energy consumption.
T: b, d
F: a, c
Phosphoenolpyruate: sugar phosphotransferase system (PTS):
a. PTS consists of 3 enzymes and low molecular heat resistant protein (HPr):
- HPr and enzyme I are cytoplasmic,
- Enzyme II is integral membrane protein and
- Enzyme III is either cytoplasmic or peripheral protein.
b. Phosphoenolpyruvate (PEP) is the high energy phosphate donor.
c. Is important for group translocation.
d. Molecule transported into the cell is chemically altered by phosphorylation and active transport
(uses ATP/ energy).
T: a, b, c, d
Catabolic reactions in bacterial cells include
a. Hydrolysis of the bigger nutrient molecules (sugar, lipids and proteins)
b. Production of complex components such as polypeptides and polysaccharides
c. Synthesis of proteins from amino acids with consumption of ATP
d. Degradation of amino acids, glycerol, monosaccharides, fatty acids and other compounds to simply molecules
T: a, d
F: b, c
Enzymes produced by bacteria have next effect:
a. Leukocidins – decrease the phagocytic activity of the leukocytes.
b. Coagulases – cause the formation of fibrin clumps and protect bacteria from phagocytosis.
c. Hyaluronidases – dissolve hyaluronic acid.
d. Kinases – are important for motility of bacteria without flagellas.
T: a, b, c
F: d
Bacterial toxin:
a. Exotoxins are produced mainly by G+ bacteria, wheras endotoxin production is almost always associates with G- bacteria.
b. Endotoxin is of protein origin and has pyogenic effect.
c. Exotoxins have specific effects to cells and tissues, not like endotoxins, which has non specific effects.
d. Endotoxin is released after cell death, after bacterial lysis.
T: a, c, d
F: b
Properties of endotoxins and exotoxins
a. Endotoxin is characteristic for all pathogenic bacteria, it is a significant virulence factor.
b. Exotoxins are of a protein nature and the genes that encode their synthesis are often carried on plasmids or bacteriophages
c. Endotoxin is a polysaccharide, found in the lipopolysaccharide layer of the cell wall of bacteria, and has non-specific effect on cells and tissues.
d. Exotoxin is released only after cell lysis, its effect is tissue-specific.
T: b
F: a, c, d
Antibiotics:
a. Are produced mainly by fungi and moulds.
b. Beta-lactam antibiotics inhibit the synthesis of the bacterial cell walls.
c. Tetracyclines inhibit the proteosynthesis of bacteria.
d. Vancomycin, kanamycin and tetracycline are produced by streptomycetes.
e. Rifampin can be toxic and inhibit nucleic acid synthesis.
f. Tetracyclines activate enzymes that cause lysis of the bacterial cell wall.
g. The similarity of the β-lactam ring to the peptidoglycan structure is used to inhibit bacterial cell wall synthesis
h. Penicillins and sulfonamides damage the cytoplasmic membrane of bacteria
T: b, c, d, e, g
F: a, f, h
Genetic code:
a. Consist of sequence of 4 nucleotides.
b. There are 64 codons, which can code various amino acids.
c. Is a sequence of nucleotides, which encodes the amino acids sequence in the polypeptide chain.
d. Non-sense codons do not code amino acids, but they stop the process of translation.
e. Is defined as degenerated, which means that some amino acids are encoded by more codons
f. Three nonsense-codons are the stop codons and occurs in the termination of translation
g. Consists of codons, which are made of three nucleotides, and they are encoding an amino acid.
h. Is a nucleotide sequence, which corresponds with the amino acid sequence in the polypeptide chain
T: a, b, c, d, e, f, h
F: g
Structure of the gene:
a. Pribnow box is the DNA polymerase recognition site in the protomer of the gene.
b. Trailer carries information about the stopping of the proteosynthesis.
c. Coding region is transcribed from DNA to mRNA.
d. Shine-Dalgarno sequence is a part of DNA terminator.
e. Promoter, leader, coding region, trailer are all transcribing to mRNA.
Terminator is not transcribing to mRNA
T: b, c, e
F: a, d
Transcription: (mRNA, tRNA, rRNA)
a. In this process the guiding strain in the 3‘→5‘ orientation is transcribed and mRNA is synthesized in opposite orientation.
b. Is a process, where DNA polymerase serves as a catalysator.
c. Promotor is transcribed as first, consist of 2 regions.
d. RNA polymerase stops its activity in the DNA region, which is called terminator.
T: a, c, d
F: b
Protein synthesis:
a. Consist of 3 steps: initiation, elongation and termination.
b. In the initiation step the protein synthesis starts with a help of modified aminoacyl –tRNA.
c. Amino-acids are transferred from the site A to the site P during the translocation reaction.
d. Enzyme peptidyl-transferase plays an imp role in the process of aminoacid activation.
T: a, b, c, d
Double check c
Horizontal gene transfer
a. Stable transductant appears after the insertion of the phage DNA to the genome of recipient cell
b. Transduction is a model of a horizontal transfer of the genes from lysed bacteria
c. The basic condition of the bacterial conjugation is the direct contact of the cell
d. The latent form of the viral genome in the host is called prophage, usually integrated into that bacterial genome
T: b, c, d
F: a
double check b
