del 1 Flashcards
1. Procaryotic cells are
a.Mycoplasmas, rickettsia and bacteria.
b.Fungi, bacteria and rickettsia.
c.Bacteria, mycoplasmas and yeasts.
d.Bacteria and fungi.
T: a
F: b,c,d
Fungi:
a. Consist of procaryotic cells, can be unicellular or multicellular.
b. Consist of eucaryotic cells which absorb nutrients from an organic material from the environment.
c. Yeast and mould are also part of fungi.
d. Molds grow as branching filaments (hyphae), which interlace to form mycelium.
e. Yeast are ovoid or spherical cells that reproduce by budding. They do not form mycelium.
T: b, c, d, e
F: a
Bacterial shape: filamentous bacteria include genera:
a. Actinomyces and Nocardia.
b. Neisseria and Klebsiella.
c. Nocardia and Streptomyces.
d. Actinomyces and pasturella.
T: a, c
F: b, d
Glycocalyx:
a. One of the functions of the glycocalyx is the adherence of the bacterium to the host cell.
b. Is a part of the flagellum, plays a role in motility of bacteria.
c. Is an imp virulence factor of pathogenic bacteria.
d. Protects pathogenic bacteria from phagocytosis.
T: a, c, d
F: b
Bacterial flagella
a. Are composed of protein flagellin and consists of 2 basic parts
b. Lophotrichous bacteria have only one flagellum at both poles of the bacterium.
c. The basal body of G- bacteria anchors the flagellum on the cell wall by four rings
d. Leptospira and borrelia for movement use endoflagella that are located in the periplasmic space
T: c, d
F: a, b
bacterial cell wall
a. Contains integrated transport proteins.
b. Is present in all bacteria without exception.
c. The main component is peptidoglycan which consist from 2 sugars and lipids.
d. One of the most imp component of the cell wall is O-antigen which is of protein origin.
e. Lipid A is an important part of the cell wall of G- bacteria, it acts pyrogenically and caused vasodilation, inflammatory reactions, and blood coagulation disorders
f. Its main component is a peptidoglycan, which consists of two types of sugars horizontally and vertically linked to each other by amino acid cross bridges
g. In G- bacteria, the petidoglycan layer includes endotoxin and teichoic acid.
h. The protoplast is formed after action of lysosome on G- bacteria, and the cell wall is completely destroyed.
T: f
F: a, b, c, d, e, g, h
Cytoplasmic membrane of bacterial cells
a. It has an amphipathic arrangement; the phosphate heads are oriented outwards and the fatty acid chains inwards
b. CPM contains 60% lipids and 40% proteins.
c. With exception of mycoplasmas bacteria don’t contain sterols, while eukaryotes do
d. Integral and peripheral proteins are part of CPM , their function is in the transport material
T: a, c, d
F: b
The internal structures of bacterial cells:
a. Mesosomes creates an irregular rolled folds of plasmatic membrance.
b. Liquid cytoplasmic component is called matrix.
c. Bacterial cell contains thousands of ribosomes.
d. Bacterial cytoplasm includes nucleus, mitrochondria and inclusions.
e. Plasma membranes can be destroyed by alcohols and polymyxins.
T: a, b, c, e
F: d
Endospores:
a. Sporulation (sporogenesis) is a process that takes 24-32 h.
b. Are metabolically very active forms, because in unfavorable conditions must ensure the survival of bacteria.
c. The parts of the endospores coat are calcium ions, mycolic acid and arabinogalactan.
d. Cortex is strongest layer of the endospore.
T: d
F: a, b, c
Spore:
a. Most of the saprophytic soil bacteria are spore forming.
b. In particular, dipicolinic acid and calcium ions are involved in spores thermoresistance, with ca-dipicolinate stabilizing the bacterial DNA
c. Spore germination consist of two phases, activation and growth, where activation is reversible and growth is irreversible.
d. The process of endospore formation within the vegetative cell takes around 10 hrs, while germination under optimal condition takes only 1-2 minutes.
T: b, d
F: a, c
Growth of bacterial population:
a. Consists of 3 basic phases.
b. Phase of growth curve is characterized by the most rapid growth and cell division.
c. M-Concentration is the highest bacterial concentration and reaches 10‘6/ml.
d. Generation time consist of phase of growth and phase of division.
T: b, d
F: a, c
Model of DNA replication:
a. Okazaki’s fragments appears after replication of the leading DNA strain with 3’ →5’ direction
b. Watson and Crick published their description of DNA structure in 1953 and they suggested how DNA might be replicated
c. The reading frame of the DNA template is oriented in the 5’→3’ direction
d. General DNA replication model does not apply in the case of E.coli conjugation and bacteriophage reproduction
T: b, d
F: a, c
