Finals Flashcards: BACTERIA, VIRUSES & THE IMMUNE SYSTEM

Bacteria

Single

Kingdom Archaebacteria

Ancient bacteria that often live in extreme environments. Example: thermophiles.

Kingdom Eubacteria

Common bacteria found almost everywhere. Example: E. coli.

Spirilla

Spiral

Cocci

Spherical

Bacillus

Rod

Bacterial Cell Structure

Cell wall, cell membrane, cytoplasm, ribosomes, DNA, pili, and flagella.

Endospore

A protective structure that allows bacteria to survive harsh conditions.

Pilus (Pili)

Hairlike structures used for attachment and exchanging genetic material.

Autotroph

An organism that makes its own food.

Heterotroph

An organism that obtains food from other organisms.

Aerobes

Bacteria that require oxygen.

Anaerobes

Bacteria that live without oxygen.

Pathogen

A disease

Bacterial Disease

An illness caused by bacteria.

Examples of Bacterial Diseases

Strep throat, tuberculosis, Lyme disease.

Antibiotics

Medicines used to kill or stop the growth of bacteria.

Food Preservation

Methods used to prevent bacterial growth in food.

Examples of Food Preservation

Refrigeration, freezing, drying, salting, canning, pasteurization.

Helpful Bacteria

Bacteria that help digestion, make foods, or recycle nutrients.

Examples of Helpful Bacteria

E. coli in intestines, bacteria used to make yogurt.

Harmful Bacteria

Bacteria that cause disease or spoil food.

Virus

A tiny infectious particle that can reproduce only inside a host cell.

Virus Structure

Genetic material surrounded by a protein coat called a capsid.

Capsid

The protein coat surrounding a virus.

Bacteriophage

A virus that infects bacteria.

Lytic Cycle

Viral cycle in which a virus reproduces and bursts the host cell.

Lysogenic Cycle

Viral cycle in which viral DNA becomes part of the host DNA before becoming active.

Lysis

The bursting of a host cell and release of new viruses.

Steps of the Lytic Cycle

Attach, inject DNA, make viral parts, assemble viruses, lyse cell.

Steps of the Lysogenic Cycle

Attach, inject DNA, viral DNA joins host DNA, host reproduces, virus later enters lytic cycle.

Viral Diseases That Follow the Lysogenic Cycle

HIV and HPV.

HIV

A virus that attacks the immune system.

HIV Transmission

Through infected blood, sexual contact, shared needles, and from mother to child.

Ways to Prevent HIV

Avoid sharing needles, practice safe sex, and get tested.

Retrovirus

A virus that uses RNA and reverse transcription to reproduce.

Examples of Viral Diseases

Influenza, common cold, COVID

Antiviral Drug

A medicine that slows the growth or reproduction of viruses.

Human Papillomavirus (HPV)

A virus that can cause warts and some cancers.

Immunity

The body's ability to fight disease.

First Line of Defense

Physical and chemical barriers that prevent pathogens from entering the body.

Is the First Line Specific?

No.

Goal of the First Line

Keep pathogens out of the body.

Mucous Membrane

Tissue that lines body openings and produces mucus.

Mucus

Sticky substance that traps pathogens.

Second Line of Defense

Internal defenses that attack invaders that enter the body.

Is the Second Line Specific?

No.

Goal of the Second Line

Destroy pathogens that enter the body.

Fever

An increase in body temperature that helps fight infection.

Inflammatory Response

The body's reaction to injury or infection causing redness, swelling, and warmth.

Histamine

A chemical that causes blood vessels to widen during inflammation.

Neutrophil

A white blood cell that quickly attacks pathogens.

Macrophage

A white blood cell that engulfs and digests pathogens.

Third Line of Defense

The immune response involving lymphocytes and antibodies.

Is the Third Line Specific?

Yes.

Goal of the Third Line

Attack specific pathogens.

Antibody

A protein that recognizes and attacks a specific antigen.

Antigen

A foreign substance that triggers an immune response.

Active Immunity

Immunity produced when the body makes its own antibodies.

Example of Active Immunity

Recovering from a disease or getting vaccinated.

Passive Immunity

Immunity gained from another source's antibodies.

Example of Passive Immunity

Antibodies from breast milk or an antibody injection.

Vaccination

Introducing weakened or inactive pathogens to stimulate immunity.

Allergy

An overreaction of the immune system to a harmless substance.

Autoimmune Disease

A disease in which the immune system attacks the body's own cells.

Examples of Autoimmune Diseases

Type 1 diabetes, lupus, rheumatoid arthritis.

Difference Between Bacteria and Viruses

Bacteria are living cells that can reproduce on their own; viruses are not cells and must use a host cell to reproduce.

Why Antibiotics Do Not Work on Viruses

Antibiotics target bacterial structures, which viruses do not have.

Importance of Vaccines

They help the body develop immunity before exposure to a disease.

Purpose of Antibodies

To recognize and help destroy specific pathogens.

Purpose of Antigens

To trigger an immune response.

Role of Macrophages

Engulf and digest pathogens.

Role of Neutrophils

Quickly attack invading pathogens.

Why Endospores Are Important

They help bacteria survive extreme conditions.

Why the Lysogenic Cycle Is Dangerous

Viral DNA can remain hidden in host cells for long periods.

Why Mucus Is Important

It traps pathogens before they enter the body.