Chapter 11 Infectious Diseases in Humans - Vocabulary Flashcards

Vocabulary flashcards covering key terms from Chapter 11 on Infectious Diseases in Humans, including pathogens, transmission, vaccines, antibiotics, and antibiotic resistance.

Infectious diseases

Diseases that can spread between people and are caused by pathogens such as bacteria and viruses.

Pathogen

A microorganism that causes disease (e.g., bacteria or viruses).

Bacteria

Single-celled organisms with a cell wall and no nucleus; some are pathogenic and some are non-pathogenic.

Virus

A non-cellular infectious agent with a protein coat enclosing genetic material; reproduces only inside living host cells.

Non-infectious disease

A disease not caused by pathogens; caused by genetics, environment or lifestyle.

Sign

An observable or measurable indication of disease (e.g., fever, rash, coughing).

Symptom

A subjective feeling of illness described by the patient (e.g., headache, fatigue).

Transmission

The spread of an infectious disease from one person to another.

Droplets

Tiny respiratory droplets expelled when coughing or sneezing that may carry pathogens.

Direct contact

Spread through skin-to-skin contact or contact with mucous membranes (e.g., STIs like HIV).

Contaminated food and water

Food or water containing pathogens due to poor handling or storage (e.g., cholera).

HIV

Human Immunodeficiency Virus; an STI that can be transmitted sexually and through other exposures.

Influenza virus

The virus that causes influenza; transmitted via droplets; vaccines are available.

Pneumococcus

Streptococcus pneumoniae, the bacterium that causes pneumococcal disease.

Pneumococcal disease

Illness caused by pneumococcus; preventable by vaccination.

Vaccine

A preparation containing an agent resembling a pathogen that stimulates antibody production to prevent disease.

Vaccination

The process of receiving a vaccine to gain protection.

Antibody

A protein produced by B cells that binds to an antigen and helps destroy the pathogen.

White blood cells

Immune cells that recognize antigens and produce antibodies; memory cells persist after infection.

Antigen

A molecule or part of a pathogen that triggers an immune response.

Memory cells

Long-lived immune cells that remember a pathogen and enable rapid antibody production on re-exposure.

Receptors on white blood cells

Proteins on WBCs that bind to antigens to activate the immune response.

Antibiotics

Drugs used to treat bacterial infections by inhibiting growth or killing bacteria; not effective against viruses.

Superbugs

Pathogens that are resistant to multiple antibiotics.

Antibiotic resistance

The ability of bacteria to survive exposure to an antibiotic due to mutations/selection.

Bacterial cell wall

Rigid layer surrounding some bacteria; target of certain antibiotics.

Bacterial DNA and plasmids

The bacterial chromosome is a single circular DNA molecule; plasmids are small circular DNA separate from the chromosome.

Flagella

Whip-like structures that enable bacterial movement.

Ribosomes

Cellular machinery that synthesizes proteins; targeted by some antibiotics.

Virus replication in host

Viruses reproduce only inside living host cells; they rely on the host cell machinery.

Antibiotics: mechanisms — cell wall synthesis

Some antibiotics prevent synthesis of bacterial cell walls, causing lysis.

Antibiotics: mechanisms — cell membrane

Some antibiotics disrupt the bacterial cell membrane, affecting permeability.

Antibiotics: mechanisms — protein synthesis

Some antibiotics bind bacterial ribosomes and inhibit protein synthesis.

Antibiotics: mechanisms — folic acid synthesis

Some antibiotics inhibit enzymes needed to synthesize folic acid, hindering growth.

Antibiotics vs viruses

Antibiotics are ineffective against viruses because viruses lack cell walls, membranes, and ribosomes.

Completing antibiotic course

Finishing the prescribed course reduces the chance of resistance developing and spreading.

Antibiotic misuse/overuse

Using antibiotics for viral infections or not completing the course promotes antibiotic resistance.