Glossary of Microbio Comprehensive
Created by Hamwich
- Brightfield microscopy
- Requires staining and heat fixing
- Darkfield Microscopy
- Used to observe live and unstained objects
- Phase-Contrast Microscopy
- -Uses direct and indirect light
-Can observe live and unstained objects
- Fluorescence Microscopy
- Uses photoluminescence to observe objects
- What are the basic requirements for cell growth?
- Temperature/pH, macro/micro nutrients, and oxygen requirements
- Obligate anaerobe
- only grow in oxygen
- facultative anaerobe
- both aerobic and anaerobic growth but grow greater in oxygen
- aerotolerant anaerobes
- only anaerobic growth but grows throughout
- oxygen required in low concentration, grows in middle of tube
- Lowering microbial counts on eating/drinking utensils
- kills microbes
- destruction of pathogens
- Genetic code
- A set of rules that determines how nucleotide sequences are converted into amino acid sequences of proteins
- complementary structure
- allows precise copying of DNA during division
- What is the energy source for DNA replication?
- DNA--> RNA code
- RNA--> AA sequences
- Sense codon
- 3 nucleotide sequence that codes for an Amino Acid
- complementary sequence to a codon
- In Translation, what is the P-site?
- The peptidyl site where the first tRNA sits
- In translation, what is the A-site?
- Acceptor site where the second codon of the mRNA pairs with a tRNA carrying the second amino acid.
- What are the two stages where we can control gene expression?
- Pre-Transcriptional Control
Post-Transcriptional Control- After the mRNA has been made, but before translation takes place.
- What are the two types of pre-transcriptional control?
- Mechanism that inhibits gene expression or decreases synthesis rate of mRNA from a gene
- Mechanism that turns on the transcription gene
- Set of operator and promoter sites and structural genes they control
- What are the two types of base substitutions (point mutations)?
- Missense mutation
- Point mutation causes a change in the codon that changes the amino acid type
- Nonsense mutation
- point mutation changes codon to a "stop" codon
- Frameshift mutation
- Deletion or insertion of a few nucleotides
- Genetic recombination
- The exchange of genes between two DNA molecules
- Transformation (Frederick Griffith)
- To absorb and recombine "naked" DNA
- Transfer of bacterial DNA via bacteriophage (virus)
- What are the two methods of transduction?
- Generalized transduction
- an accidental packaging of bacterial DNA instead of phage DNA
- Specialized transduction
- phage DNA includes toxin genes that the bacteria can use
- Conjugative plasma (F factor plasmid)
- Carries genes for sex pili and transfer of the plasmid
- What are the different types of plasmids?
- 1. Conjugative (F factor)
2. Dissimilation plasmid
3. Resistance factors (R factor)
- Dissimilation plasmid
- enzymes to break down unusual sugars or hydrocarbons
- What dangers do R plasmids present to humans?
- R plasmids can prevent antibiotics from working for humans which means humans can be resistant to antibiotics and become incapable of being cured with antibiotics
- segments of DNA that can move from one region of DNA to another
- Crossing over
- process were foreign DNA is inserted into a chromosome by breaking and rejoining the chromosome
- Polymerase Chain Reaction (PCR)
- Used to make multiple copies of a piece of DNA enzymatically
- Preparing cells to take up DNA (making them competent)
- How are gene libraries made in prokaryotic and eukaryotic organisms?
- -Genomic libraries are made from restriction enzyme digests of an organisms DNA that are packaged into “books”.
-“books” are stored as a bacterial or phase strain.
- Small interfering RNA (siRNA)
- therapeutic version of RNA that can bind to disease causing genes of viruses or cancer cells.
- Toll-like receptors
- Induce cytokine activity and attach to components found on PAMP pathogens
- Function of basophils
- release histamine that causes inflammation
- Function of Eosinophils
- Kills parasites with oxidative burst
- Function of Neutrophil
- Phagocytizes bacteria and fungi
- Function of monocytes
- cause inflammation and perform phagocytosis
- Function of dendritic cells
- Phagocytize bacteria and present antigens to Tcells
- What three things can the activation of the complement system do?
- 1. Cytolysis (osmotic lysis)
2. Opsonization: promotes phagocytosis
- MAC complex
- Membrane Attack Complex→ creates a hole on a pathogen’s cell membrane and makes transmembrane channels for flow of extracellular fluid into pathogen and it bursts
- How can bacteria evade the complement system?
- -Capsule production – blocking C3b and C4b binding sites
-Sialic acid- discourages opsonization and MAC formation
- Inactivation of complement via bacterial produced enzymes.
- What does IFN-α and IFN-β do?
- interfere with viral multiplication by signaling neighboring cells of an ongoing viral infection
- What is the bacterial equivalent of transferrins?
- iron-binding blood plasma glycoproteins that control the level of free iron (Fe) in biological fluids
- Who is the father of the theory of immunity?
- Paul Ehrlich
- A molecule, usually a protein, that stimulates an adaptive immune response.
- A protein molecule secreted by B cells (plasma cells) that can bind to antigens.
- What are the 2 arms of the adaptive immune system and what cell type is important for each?
- Humoral ( B lymphocytes)
- What is a hapten and why does it need a carrier?
- Hapten: low molecular weight compounds that need a carrier to elicit an immune response (antibodies)
- How many polypeptide chains and binding sites does an antibody have?
What is the part of the antigen that binds to the antibody called?
- i. 4 Polypeptide chains
ii. 2 binding sites- Variable and Constant
iii. Antigens bind in the Variable region
- What is passive immunity?
- the process of providing IgG antibodies to protect against infection
- Which form of isotypes are in monomer form?
G, D and E
- What form is the isotype IgM in?
- What form is the isotype IgA in?
- What is the function of isotype IgG?
- Enhance phagocytosis, neutralize toxin/viruses
- What is the function of isotype IgM?
- Effective against microorganisms and agglutinating antigens
First antibodies produced in initial infection
- What is the function of isotype IgA?
- localized protection on mucosal surfaces
- What is the function of isotype IgD?
- unknown serum function, presence on B cell functions in initiation of immune response
- What is the function of isotype IgE?
- allergic reactions, lysis of parasitic worms
- Where are IgG isotypes found?
- Blood/lymph, intestine
- Where are IgM isotypes found?
- Blood/lymph, B cell surface
- Where are IgA isotypes found?
Secretions (tears, saliva, mucus)
- Where are IgD isotypes found?
- Blood/lymph, B cell surface
- Where are IgE isotypes found?
- Blood, bound to mast and basophil cells throughout body
- What 5 things can antibodies do?
- 1. Agglutination
4. Antibody-dependent cell mediated cytotoxicity
5. Activation of complement
- antibodies cause antigens to clump together
- the antigen is coated with antibodies that enhance its ingestion and lysis by phagocytic cells
- IgG antibodies inactivate microbes by blocking their attachment to host cells
- Antibody-dependent cell mediated cytotoxicity
- The killing of antibody-coated cells by NK cells and leukocytes, occurs with organisms too large to phagocytize
- activation of complement
- inflammation and cell lysis
- What negative effect can antibodies have on the host?
- IgE antibodies can cause allergic reactions
- Thymic selection
- Weeding out process of T cells that won’t recognize MHC molecules of the host and T cells that will attack host cells.
-prevents the body from attacking its own cells
- What are the basic T cell forms?
- T helper cells
T cytotoxic cells
- Function of Helper T cells
- control the immune response through cytokines (chemical messengers)
- Function of cytotoxic T cells
- kill intracellularly infected cells
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