Download MCB 2010C Microbiology Final Exam Latest 2024|2025 FALL-SPRING FSW GRADED A+ and more Exams Microbiology in PDF only on Docsity!
MCB 2010C Microbiology Final Exam Latest
2024 |2025 FALL-SPRING FSW GRADED A+
Microorganisms characterized by the lack of a nucleus are prokaryotes What are characteristics of non-living viruses?
- Need host to act as a metabolic source
- Lack their own cell membrane
- Unable to reproduce independent of host cell
- Do not grow larger in size What is found in ALL bacterial cell walls? Peptidoglycan A bacterial cell moving away from toxins is an example of Chemotaxis What powers the process of flagella rotation? A proton gradient What structure allows bacteria to hide from white blood cells?
Capsule What structure is used to exchange DNA? Pilli What is the mordant used in gram staining? Iodine What structure allows for bacteria to stay dormant for long periods of time? Endospore When using low power (4x), what is the total magnification? 40x Which two group are endospore formers? Bacillus and Clostridium The power to distinguish between two separate objects in close proximity? Resolution Where does glycolysis occur? In the Cytoplasm
Some bacteria can use Nitrate to generate a proton motive force. In these bacteria, nitrate serves as the ___________ in the process of ___________ 1)Electron acceptor
- Anaerobic respiration The reaction that breaks down ATP to form ADP is? Exergonic Which enzyme breaks down proteins? Proteases During Aerobic metabolism, which two biochemical pathways does substrate phosphorylation occur? Glycolysis and The Krebs Cycle From one molecule of glucose that undergoes aerobic respiration, how many ATP are produced from substrate phosphorylation? 4 What are two eukaryotes? Fungi and Algae Which of the following pairs is composed of only protein?
Bacterial flagellum and pilli If a student left out safranin in the gram stain procedure, then..... All of the gram + would be purple and gram - would be colorless If a bacteria does not grow in the absence of oxygen.. Then it is an obligate aerobe Bacteria that grow at pH 1- 2 Acidophiles pH close to 10 Alkaliphiles Where would you likely find psychrophiles? Mountain lakes at temp 12 degrees celsius Which bacteria would prefer to grow in ice caves? Psychrophiles EMB agar selects for _______ microbes and is differential based on ________ Gram negative:Lactose fermentation
Gram + Rod, common culprit of food positing in deli meat, psychrophile, lethal to fetus Listeria monocytogenes Gram + cocci, can cause skin infections, appears yellow on MSA Staphylococcus aureus Gram - cocci, it has a capsule, LPS, and fimbrae, causes STDs Neisseria gonnorhea Gram - rod, can cause food poisoning, a lactose fermenting bacteria that grows pink on MAC and green on EMB Escherichia coli Gram - rod, can cause food poisoning, it is NOT lactose fermenting, and browns white/clear on MAC and EMB Salmonella enteritidis Most simple prokaryote cell Double stranded DNA, ribosomes, cell membrane, and cytoplasm What re the three structural qualities unique to a gram - bacteria?
Thin peptidoglycan, LPS, periplasmic space Who discovered that H. pylori causes ulcers? Dr. Barry Marshall Who discovered Archaea? Dr. Woese who taught at UIUC mRNA is formed by the ________ of a gene on the DNA template strand Transcription What components are directly involved in Transcription DNA and mRNA The lac operon is usually in the _______ position and is activated by an ______ molecule off : inducer What is not true about a plasmid? It is required for normal cell function (it is not) Which genetic material can be transferred by all three methods of horizontal gene transfer? A single drug resistance gene
Synthesis of an inducible enzyme requires? Substrate bound to repressor What enzyme is necessary for the breakdown of lactose into glucose and galactose? Beta-galactosidase What is directly controlled by operons? DNA transcription Conjugation requires with bacterial cell structure? Pilli Gene regulation can involve a protein repressor that blocks _____ from initiating transcription RNA polymerase The Ames test is a screening test used to predict whether a chemical is likely to cause ______ in human cells? Mutations In the Ames test, if a his- organism exposed to chemical X and undergoes a mutation and becomes his +, will it be able to grow on a medium without histidine?
YES
In the ames test if a high rate of bacterial growth appears on the experimental plates (without histidine), the the chemical tested causes mutations YES A small circular piece of extrachromosomal DNA Plasmid Induces GFP activity by activating transcription IPTG Stabilizes DNA CaCl Pokes small holes in the bacterial cell wall Heat Shock Gene that encodes B-lactamase protein bla gene Best known examples of viruses that cause latent infections are?
A _______ is specifically able to have a long-term relationship with the host known as lysogeny Temperate virus What is the key difference between "rough" and "smooth" strains of S. pneumoniae Smooth bacteria can evade the immune system The HIV virus has a narrow host range, this this is because..... The virus infects only T helper cells of the human immune system Viruses acquire envelopes around their nucleocapsids during release Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms Latent Which of the following viruses requires RNA-dependent RNA polymerase? (+) RNA viruses Slow gradual changes in sequence genetic drift
Antigenetic shift in influenza virus is dependent on A segmented genome encoded on several RNA molecules What are possible molecules that the bacteriophage tails recognize to allow adsorption? LPS, techoic acid, and peptidoglycan Viruses are measured in nanometers Is HIV a Virus, Bacteria, or both Virus Is Whooping cough a Virus, Bacteria, or both Bacteria Is pneumonia a Virus, Bacteria, or both Both Is Lyme disease a Virus, Bacteria, or both Bacteria antimicrobial chemotherapy
prophylaxis use of a drug to prevent potential for infection in a person at risk antimicrobials all inclusive for any antimicrobial drug regardless of its origin antibiotics substances produced by natural metabolic processes of some microorganisms that. can inhibit or destroy other microorganisms semisynthetic drugs drugs that are chemically modified in the laboratory after being isolated from natural sources synthetic drug antimicrobial compounds modified in the laboratory after being isolated from natural sources broad spectrum antimicrobials effective against a wide variety of microbial types; for example, a drug effective against both gram-positive and gram-negative bacteria five major components of useful drug targets
inhibition of cell wall synthesis (cidal) breakdown of the cell membrane structure or function (cidal) interference with functions of DNA and RNA (static) inhibition of protein synthesis (static) blockage of key metabolic pathways (cidal) spectrum range of activity of a drug narrow-spectrum drugs effective on a small range of microbes beta-lactam drug characteristics highly reactive 3-carbon, 1 nitrogen ring interferes with cell wall synthesis over half of antimicrobic drugs are beta-lactams penicillians and cephalosporins are most prominent most important natural forms of penicillin penicillin G and V transpeptidase function cross links NAG and NAM on ppgn
spontaneous mutations acquisition of new genes or sets of genes via transfer from another species intermicrobial transfer intermicrobial transfer types transfer of R plasmids encoded with resistance transposons duplicated and inserted from one plasmid to another (or plasmid to chromosome) what is blood agar for Used to cultivate pathogenic organisms that produce hemolytic enzymes hemolysis lysis of erythrocytes catalyzed by enzymes called hemolysins what are the 3 hemolysin types alpha, beta, gamma staphylococci characteristics common in skin and mucous spherical cells in irregular clusters gram positive lack spores and flagella may have capsules 31 species
staphylococcus aureus characteristics large, round, opaque colonies optimum temp 37 degrees C facultative anaerobe can withstand high temp, salt, and extreme pH produces many virulence factors immune system goals stop foreign invaders keep invasion and infection under control maintain a memory of infection how does skin help immune system difficult for microbes to penetrate dermis - tightly woven connective tissue epidermis - dead cells filled with keratin, flakes off, dry environment antimicrobial substances that help immune system lysozymes - degrades ppgn peroxidases - breaks down H2O lactoferrin/transferrin - binds iron antimicrobial peptides (AMPs)
