A-Level Biology: Infection, Immunity, Microbiology, and Pathogens

Comprehensive vocabulary flashcards covering microbiology, immunology, virology, antimicrobial mechanisms, and laboratory techniques.

Phages

Viruses that specifically target and infect bacterial cells.

Phage Therapy

A therapeutic strategy using bacteriophages to target and eliminate specific bacterial infections, such as persistent $Mycobacterium$ infections.

Artificial Active Immunity

Immunity acquired through the injection of antigens (such as a vaccine), stimulating the body's immune system to produce specific antibodies and long-lived memory cells.

Artificial Passive Immunity

Short-term immunity acquired through the direct injection of pre-formed antibodies into an individual, providing immediate protection without forming memory cells.

Minimum Inhibitory Concentration (MIC)

The lowest concentration of an antimicrobial substance that completely prevents visible growth of a specific bacterium in culture.

Aseptic Technique

A set of specific sterile laboratory practices designed to prevent contamination from unwanted microorganisms during microbiological procedures.

Dilution Plating

A microbiological counting method in which a bacterial broth culture is serially diluted and spread onto agar plates to determine the concentration of viable, colony-forming cells.

Turbidity

The cloudiness of a liquid culture caused by suspended cells, measured using a colorimeter or photometer to indirectly quantify microbial cell density via optical density.

Bactericidal Antibiotic

An antibiotic that directly kills bacterial cells.

Bacteriostatic Antibiotic

An antibiotic that inhibits bacterial cell division and growth without immediately killing the existing bacteria.

Neoantigens

Novel, altered cell-surface proteins resulting from genetic mutations in cancer cells that are absent from normal, healthy body cells.

Adoptive Cell Therapy

A form of cancer immunotherapy where a patient's $T$ cells are isolated, multiplied to large numbers in a laboratory, and then re-infused into the patient to destroy cancer cells.

Oncolytic Virotherapy

A cancer treatment method utilizing engineered or naturally occurring viruses that selectively infect, replicate within, and lyse cancer cells.

CAR-T Cells

Genetically modified $T$ cells engineered with an artificial chimeric antigen receptor ($\text{CAR}$) to recognize and destroy cancer cells possessing specific surface antigens.

$$\beta\text{-Amyloid}$$

An abnormal protein that aggregates into insoluble neurotoxic plaques within the brains of individuals suffering from Alzheimer's disease.

Zone of Tolerance

The specific temperature range over which an organism can maintain metabolic activity and survive for an extended duration (such as longer than $5000\,\text{min}$).

Forensic Entomology

The application of insect biology, particularly the predictable succession of insect species and developmental stages on a corpse, to estimate post-mortem interval ($\text{PMI}$) and determine if a body was moved.

Reverse Transcriptase

A retroviral enzyme that synthesizes complementary double-stranded $DNA$ from a single-stranded viral $RNA$ template.

Integrase

An enzyme produced by retroviruses, such as $\text{HIV}$, that incorporates the newly synthesized viral $DNA$ into the host cell's nuclear genome.

Tumour Necrosis Factor (TNF)

A cytokine signaling protein released by immune cells that mediates inflammation and stimulates phagocytosis by macrophages.

Castaneroxy A

An active chemical compound extracted from European chestnut tree leaves that weakens $\text{MRSA}$, prevents toxin synthesis, and reduces skin infection size without disrupting native skin flora.

Colostrum

The initial form of breast milk produced during the first few days after birth, rich in oligosaccharides and maternal antibodies such as $\text{IgA}$.

Maltoporin

A transport protein embedded in the outer membrane of $E.\;coli$, coded by the $\text{lamB}$ gene, which facilitates sugar uptake and acts as the specific binding receptor for the $\lambda\text{ phage}$ J protein.

Mast Ring

A circular ring of filter paper with radiating arms, each impregnated with specific antibiotics or concentrations, used on an agar spread plate to determine bacterial antibiotic susceptibility via zones of inhibition.

VP35

A structural protein of the Ebola virus that suppresses the host cell's immune defenses by inhibiting the synthesis of interferon.

Mycolic Acid

A waxy lipid molecule present in high amounts within the cell wall of $Mycobacterium\;tuberculosis$, conferring protection against lysozyme, desiccation, and hydrophilic antibiotics.

Albicidin

A bacterial phytotoxin that causes sugarcane leaf scald by impairing chloroplast development and inhibiting the prokaryotic enzyme $DNA$ gyrase.

DNA Gyrase

A bacterial topoisomerase enzyme that catalyzes the negative supercoiling of double-stranded prokaryotic $DNA$, essential for normal replication and transcription.

ELISA

An enzyme-linked immunosorbent assay that uses surface-bound capture antibodies, specific antigen binding, and secondary detection antibodies tagged with an enzyme or dye to identify and quantify biological substances.

Holins

Small transmembrane viral proteins expressed during the late stage of a bacteriophage lytic cycle that form pores in the bacterial cytoplasmic membrane, allowing lysins to reach the peptidoglycan wall.

Lysins

Enzymes coded by bacteriophage genomes that degrade the peptidoglycan cell wall of bacteria, resulting in hypotonic lysis and release of progeny virions.

Endogenous Retroviruses (ERVs)

Ancient retroviral $DNA$ sequences integrated into the human germline genome that are passed down vertically across generations and regulated epigenetically.

Methanotrophs

Specialized bacteria capable of assimilating methane ($\text{CH}_4$) as their sole carbon and energy source, playing a major role in mitigating atmospheric greenhouse gas levels.

Gram-Negative Bacterial Envelope

A bacterial cell barrier consisting of an inner plasma membrane, a thin peptidoglycan layer, and a distinctive lipopolysaccharide-containing outer membrane.