im gonna fail

What is a mutation?

Change in DNA sequence

Main sources of mutations

Replication errors; mutagens

What is a neutral mutation?

No effect on protein function

What is a harmful mutation?

Alters or destroys protein function

What is a beneficial mutation?

Provides genetic variation for evolution

What is a frameshift mutation?

Insertion/deletion that shifts reading frame

What is a null mutation?

Completely nonfunctional protein

Example of base analog mutagens

5-bromouracil, 2-aminopurine

Example of alkylating agents

Nitrosoguanidine, EMS

Example of intercalating agents

Ethidium bromide, acridine orange, actinomycin D

Effect of UV radiation

Thymine dimers

What is transformation?

Uptake of DNA from environment

What is transfection?

Transformation using viral DNA

What is conjugation?

DNA transfer via cell-to-cell contact

F⁺ cell

Donor with plasmid

F⁻ cell

Recipient without plasmid

Result of conjugation

F⁻ becomes F⁺

What is an Hfr strain?

F plasmid integrated into chromosome

Why are Hfr strains important?

High recombination rates

What is transduction?

DNA transfer via virus

Generalized transduction

Any gene transferred

Example of generalized transduction

Salmonella enteritidis + P22 phage

Specialized transduction

Specific genes transferred

Examples of specialized transduction

E. coli + λ (lambda) phage

What is phage conversion?

Virus changes bacterial phenotype

Example of phage conversion

Corynebacterium diphtheriae produces toxin

What are plasmids?

Independent circular DNA

What are R plasmids?

Antibiotic resistance plasmids

Examples of virulence factors

Coagulase, hemolysin, enterotoxin

What is CRISPR?

Bacterial immune system against foreign DNA

What are transposable elements?

“Jumping genes”

Example of insertion sequence

IS2

Examples of transposons

Tn5, Tn10

What is genetic engineering?

Manipulating DNA

Example of genetic engineering

Human growth hormone gene in bacteria

What do restriction enzymes do?

Cut DNA at specific sequences

Where are restriction enzymes found?

Prokaryotes (bacteria)

What is gel electrophoresis?

Separates DNA by size

DNA moves toward which electrode?

Positive electrode

Chemical used to visualize DNA

Ethidium bromide

What is PCR?

DNA amplification

Inventor of PCR

Kary Mullis

Example uses of PCR

Detect coronavirus Forensic identification

What is cloning?

Making identical DNA/cells

What is a gene library?

Collection of cloned DNA fragments

What are nucleic acid probes?

Detect specific DNA sequences

Are viruses living?

Not fully; require host

What is a virion?

Complete virus particle

What types of viral genomes exist?

DNA or RNA; ss or ds

Virus structure components

Capsid, nucleic acid, ± envelope

Examples of bacteriophages

T4, λ (lambda)

Example of plant virus

Tobacco Mosaic Virus (TMV)

Examples of animal viruses

Herpes, Influenza, HPV

Steps of viral replication

Adsorption

Example of host specificity

Hepatitis B to liver, Poliovirus to nerve cells, Rabies to mammals

What are cytopathic effects?

Virus-induced cell damage

Examples of cytopathic effects

Inclusion bodies, syncytia

What is a provirus?

Viral DNA integrated into host

Example of latent infection

Herpes virus

Examples of cancer-causing viruses

HPV, Hepatitis B, HTLV-I

What is a lytic phage?

Kills host cell

Lytic Phage Example

T4 phage

What is a lysogenic phage?

Integrates into host DNA

Example of Lysogenic Phage

λ phage

What is lysogenic conversion?

Virus gives bacteria new traits

Examples of lysogenic conversion toxins

Vibrio cholerae to cholera toxin Clostridium botulinum to botulinum toxin Corynebacterium diphtheriae to diphtheria toxin

What is a plaque assay?

Measures virus quantity

What is ELISA?

Detects viral proteins

What is a viroid?

RNA only infectious particle

Example of Viroid

Potato spindle disease

What is a prion?

Protein-only infectious agent

Examples of prion diseases

Mad cow disease, Creutzfeldt-Jakob disease, Kuru

3 divisions of immune system

Physical/chemical barriers; nonspecific immunity; specific immunity

First line of defense

Barriers that block pathogen entry

Second line of defense

Inflammation and phagocytosis

Third line of defense

Adaptive immunity via lymphocytes

What does immune system recognize?

Self vs nonself

Autoimmune disorder

Immune system attacks own tissues

Primary lymphatic organs

Bone marrow; thymus

Secondary lymphatic organs

Lymph nodes; spleen

Function of lymph

Transports WBCs, fats, debris, pathogens

What are leukocytes?

White blood cells

Granulocytes

Mast cells; eosinophils; basophils; neutrophils

Agranulocytes

Monocytes; macrophages; B cells; T cells

What are cytokines?

Cell signaling molecules regulating immunity

Physical barriers examples

Skin; mucus; cilia

Chemical barriers examples

Acid; enzymes; wax

Human microbiome function

Competes with pathogens

Example of microbiome imbalance

Crohn’s disease; ulcerative colitis

Main phagocytes

Neutrophils; macrophages; dendritic cells

Natural killer cells function

Kill virus-infected cells

Mechanism of NK cells

Punch holes in infected cells

5 signs of inflammation

Rubor; calor; tumor; dolor; loss of function

What is pus?

Dead cells + bacteria

Pyogenic bacteria examples

Streptococci; Staphylococci; Gonococci; Meningococci

Normal body temperature

37°C (98.6°F)

Low-grade fever

37.7–38.3°C

High fever

40–41.4°C

What are pyrogens?

Substances that cause fever

Exogenous pyrogens examples

Bacteria; viruses; endotoxins