Unit 1 Human Bio

what are most diseases caused by?

bacteria, viruses, protozoas

Bacteriophage (virus)

microscopic organisms that can infect hosts, like humans, plants or animals. They're a small piece of genetic information (DNA or RNA) inside of a protective shell (capsid). Some viruses also have an envelope. Viruses can't reproduce without a host

what type of viruses contain RNA? what is reverse transcript and why is it needed?

viruses that contian RNA: retroviruses

reverse transcript: turns RNA into DNA

Describe the lytic cycle

1) attatchment

2) injection

3) cell take-over

4) assembly

5) cell lysis (burst)

FAST PACE AND PASSES (ebola, flu)

Describe the lysogenic cycle

1) attachment

2) injection

3) incorporation

4) replication

5) introduction (sometimes)

SLOW, DOESN’T PASS (HIV)

3 types of bacteria

-cocci (round shaped)

-bacilli (short and rod-shaped)

-spirilla (spiral, corkscrew shaped)

Obligate aerobe

requires oxygen

obligate anaerobe

Cannot survive in the presence of oxygen

Facultative anaerobe

organism that can survive with or without oxygen

How do bacteria usually reproduce?

Binary fission: asexual

Conjugation: sexual

Endospore formation: hibernation

What are 3 ways bacteria is helpful to humans?

1) aids digestion

2) protects against infection

3) fermentation

When should antibiotics be used, and how can we prevent misuse?

-used to destroy or inhibit growth of bacteria

-we can prevent misuse by using only when needed

who developed the first vaccine?

Edward Jenner- did it by using cowpox to provide immunity to smallpox

What did Pasteur and Koch do?

Pasteur: pasteurization to kill disease causing agents in food and beverages

Koch: linked a specific microorganism to a specfic disease (namely anthrax)

what is the first line of defense?

physical and chemical barriers that keep pathogens out (skin, mucus)

What is the second line of defense?

inflamation: swelling, redness, heat

complement: proteins punch holes in pathogens

fever: raises body temp to slow down pathogens

memory cells

long lasting cells that "remember" a pathogen

effector cells

short-lived cells that take effect immediately against the antigen and any pathogens producing that antigen

MHC marker

a self-recognition protein on a body cell

Antigen-presenting cells (APCs)

Cells that present antigens to T cells.

active immunity

A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens

passive immunity

the short-term immunity that results from the introduction of antibodies from another person or animal.

vaccine

substance prepared from killed or weakened pathogens and introduced into a body to produce immunity

Autoimmune Disorders

Immune system attacks body's own tissues (diabetes, lupus)

How do viruses reproduce?

they invade and take over host cells

Which diseases are caused by bacteria?

tuberculosis and step throat

What is the main function of the skin in the immune system?

The skin is a basic surface barrier.

How do mucous membranes contribute to the body's defense against pathogens?

Mucous contains lysozymes, which are infection-fighting substances.

What are three chemical barriers that are part of the first line of defense?

Lysozyme (infection-fighting substance), pH in the stomach and urine, flushing effect like urine, diarrhea, and sneezing.

What is the process of inflammation and its purpose in the immune response?

Inflammation occurs when you cut, bump, or contact something harmful; it gets swollen, hot, and painful, signaling the brain to send WBCs.

What is the function of fever in fighting infections?

Fever alerts the body of infection and increases defense activities while making the environment too hot for most pathogens.

Compare the second and third lines of defense in the immune system.

The second line is non-specific and handles less serious issues; the third line is specific, uses memory, and deals with more serious issues.

How do B cells contribute to the adaptive immune response?

B cells work with T cells to recognize a non-self marker, then divide repeatedly and build antibodies.

What is the role of helper T cells in the immune system?

Helper T cells alert the B cells of APCs.

What are antibodies and how do they help eliminate pathogens from the body?

Antibodies are Y-shaped proteins produced by B cells to combat antigens.

Define "immunological memory" or "memory cells" and explain its importance in preventing disease

memory cells are cells that remember the "enemy" (infections/viruses) to help for later attacks

What is the difference between active and passive immunity?

active: first dose elicits primary immune response (flu shot)

passive: injections of antibodies to persons infected with pathogens (cancer, ebola)

How do vaccines work to provide immunity against specific diseases?

vaccines are made from killed or weakened pathogens, inactivated toxins, or genetically engineered viruses- it impacts/targets the infection it is made for

Why do pharmaceuticals companies focus on production of medications instead of finding a cure?

It's much easier and possible for people to access medicine that can "cure" them rather than a low access/limited cure

How does taking Benadryl or Claritin alleviate your symptoms?

These are antihistamines which are anti inflammatory drugs used to relieve short term symptoms, like a cold or allergies