Pages 30 Through..... Flashcards
Not always present, carbohydrate – protein complex, coded for by viral genes, antigenic (Stimulate production of host antibodies), readily undergo mutation changing the structure of the _________ so no longer recognizable by previously made antibodies.
Spikes
Rabies, ebOla hemorrhagic fever
Examples of helical virus
Nucleic acid type, method of replication, morphology.
Viral Taxonomy
Lytic cycle, lysogenic cycle
Bacteriophage
Virus enters bacteria, viral replication, lyse host bacteria.
Lytic cycle
Virus enters bacteria, viral genome integrated into bacterial chromosome, remains a part of bacteria until lytic cycle resumed
Lysogenic cycle
Not always present, external to capsid, lipids, proteins, and carbohydrates, sometimes formed by a host plasma membrane.
Envelope
Infect E. coli, follows lytic lifecycle, attachment to receptor on E. coli via tail fibers, penetration (uses lysozyme to we can so wall), biosynthesis, maturation, release.
T even bacteriophages
Early genes in code proteins for phage production, late genes and code capsid proteins. Eclipse period – No complete phage present just phage parts.
T even bacteriophages biosynthesis
Said, DNA, sheath, tail fibers, pin, baseplate, lysozymes.
Bacteriophage parts
Lambda phage, step one phage injects DNA, step two phage DNA circularizes and enters lytic cycle or lysogenic cycle, step three DNA and proteins are assembled into verions, step four cell lysis releasing phage virions
Lytic cycle
Lambda phage, step one phage injects DNA, step two DNA circularizes and enters lysogenic cycle, step three phage DNA integrates with bacterial chromosome by recombination becoming a prophage, step for lysogenic bacterium reproduces normally. Excision of prophage (following stress) virus enters the lytic cycle.
Lysogenic cycle
Step one prophage exists in host cell, step two phage genome excises carrying with it adjacent gene from host, step three phage matures and cell lyses releasing phage carrying host gene, step for phage infects cell, step five prophage and host DNA become integrated into new host DNA, step six lysogenic cell can metabolize galactose.
Specialized transduction
Proteins and glycoproteins on host cell, penetration results in capsid on inside of host cell, endocytosis, fusion with plasma membrane, uncoating, removal of protein coat from viral nucleic acid.
Animal viruses
Viral proteins replicate viral DNA in host nucleus, viral capsids are produced in the cytoplasm, capsid and proteins are transported to the nucleus, verion is constructed, verion transported to cell membrane by endoplasmic reticulum- Golgi membrane- release
DNA viruses
Lysogenized host cells have been implicated in cancer
Papovavirus
Buying two enzyme at some other location other than the active site.causes alteration in the shape of the enzyme which results in an activation of the enzyme. Mercury is an example.
Noncompetitive inhibitior
Chemicals compete with substrates for the binding site on an enzyme.
Resemble substrates but cannot be converted into product. Reversible or irreversible.
Competitive inhibition
Sulfa drugs compete for binding of enzyme in folic acid biosynthesis. Bacterial growth is inhibited due to blocked pathway. Humans do not have the folic acid biosynthetic pathway.
How sulfa drugs work/ competitive inhibition
Protein catalyst. Reduces the activation energy required for the reaction. Not altered by the reaction. Increases the rate of the reaction. Specific to a particular reaction. Active site for substrate binding. Mediated by substrate concentration.
Enzymes
Non-protein component of enzymes required by some
Cofactors
NaDh, FADH, shuttle electrons
Coenzymes
Maximum conversion of substrate to product. When all enzymes are bound to substrate.
Maximum velocity of the enzyme
PH, temperature, salt concentrations, cofactor availability.
What alters enzyme function (shape, bending bonds)
Energy source comes from chemicals, chemotrophs. Carbon source? Organic compounds. Final electronic exceptor 02. Animals fungi protozoa bacteria
Chemoheterotroph
Chemoheterotroph. Final electronic acceptor not O2.
Organic compound or inorganic compound.
Fermentation or electron transport chain.
Energy source, light, phototrophs, carbon source, CO2, photoautotroph, uses H2O to reduce CO2, oxygenic photosynthesis
Plants algae cyanobacteria
Induces chromosome alteration. Remove the piece of # 8 to the end of #14, translocations. Interferes with cell death. Causes Burkitt’s lymphoma.
Epstein-Barr virus
Inserts viral genome into host chromosome. Overrides cell cycle control. Found in cervical cancer us.
HPV – human papillomavirus
Caused by insertional mutation of RNA virus
T-cell leukemia
Mostly from rna retroviruses (viral DNA synthesized from viral RNA). Viral DNA inserts into host chromosome. May carry oncogenes in viral genome insertion may trigger host proto-oncogenes
Viruses and cancer
Viruses use existing host cell biology for their own replication. Attacking these functions will have a negative impact on host.
Antiviral medications
Really only effective method of dealing with viruses. Prevention not cure.
Vaccines
Bar viral penetration. Bar transcription and translation. Prevent viral maturation.
Antiviral drug therapy targets
Interferes with the viruses ability to bind to receptors on the outside surface of the cell it tries to enter
Entry inhibitor
Interfere with the viruses ability to fuse with the cellular membrane preventing virus from entering a cell.
Fusion inhibitors
Prevent the hiv enzyme reverse transcriptase from converting single-stranded HIV RNA into a double-stranded HIV DNA
Reverse transcriptase inhibitors
When a faulty building block is added to a growing HIV DNA chain no further correct dna building blocks can be added halting HIV DNA synthesis
Nucleside/nucleotide RT inhibitors are faulty building blocks for DNA
Bind to RT, interfering with its ability to convert HIV RNA into HIV DNA.
Non-nucleoside RT inhibitors
Block the HIV enzyme intgrase which the virus uses to integrate it’s genetic material into the DNA of the cell it has infected
Integrase inhibitors
Interfere with the HIV enzyme called protease which cut HIV proteins into smaller individual proteins. Nip and tuck proteins will affect all cells.
Protease inhibitors
One pill
Combination drugs
Retrovirus, acquired by intimate contact, parenteral, invades T helper lymphocytes, attaches to Cd4 proteins on T cell surface. Reverse transcriptase is used in viral replication
HIV/AIDS
HIV replication
See diagram in book
25% of those infected will clear the virus on their own. Shows that The immune system is capable of mounting effective response, five years from a vaccine harvoni 90% cure rate
Hepatitis C
Inflammation of the liver, the most common cause of liver cancer, a B and C are common types, D requires prior infection by b
Hepatitis
Single-stranded RNA a virus, vaccine available
Hepatitis a
DN a virus Parenteral, intimate contact, chronic liver disease, vaccine
Hepatitis B
Single-stranded RNA a virus, parenteral chronic liver disease, no vaccine.
Hepatitis C
Latent virus you never get rid of reemerges from the nervous system (support cells and nerves) Symplex is cold sores, Vericella virus chickenpox, lymphocrypto virus mononucleosis, Roseolovirus roseola, reemergence doing due to immunosuppression stress UV radiation hormonal shifts.
Herpes
Spikes attach to receptors, anti-sense RNA virus makes positive RNA to make proteins, genes for spikes mutate easily and often
Influenza
Injection of blood or bodily fluids, needlesticks, sharing needles.
Parenteral
+ sense strands function as messenger RNA, can translate proteins directly from the strands, most encode proteins which repress host RNA polymerase, RNA dependent RNA polymerase
RNA viruses
Synthesizes the compliment strand of RNA, if reading the plus strand, makes the minus sense strand
Rna dependent RNA polymerase
All RNA synthesis and capsid protein synthesis occurs in the cytoplasm of the host cell, maturation – package viral RNA into capsid, release from host cell
RNA virus pathway
The capacity to do chemical work, transport work, mechanical work.
Energy
Entropy
Randomness
Endergonic
Requires energy
Change in G is greater than zero
Exergonic
Releases energy
Change in G is less than zero
Classes of chemical reactions
Redox reaction
Dehydrogenation reaction
Phosphorylation reaction
Redox reaction
One substrate is oxidized and the other is reduced
Oxidation
The loss of an electron from an Atom or molecule, often produces energy
The gain of an electron by an atom or molecule
Reduction
The removal of one proton/one electron. Most biological oxidations.
Dehydrogenation
Addition of a phosphate group. ATP is the energy Currency of cells.
Phosphorylation
ATP is usually generated when a high-energy phosphate is directly transferred from a phosphorylated compound (a substrate) to adp.
Substrate level phosphorylation
Pulls and electron
Oxidative phosphorylation
Electrons from photosynthetic pigments are excited to a higher level by light energy
Photophosphorylation
Assists enzymes by excepting hydrogen Adams that have been removed from a substrate. This energy can be used to generate ATP later reactions.
N a D +
