Exam 1: Lecture 2 Flashcards
How do we develop immunity?
- virus enters the body
- virus enters cell
- virus will do what it does and replicate inside cell
- virus product released, APC will bind it
- APC will displace virus to activate helper T-cell
- T helper cells causes B cell to make antibodies, which will block virus from infecting cells and mark for destruction
- Cytotoxic T cells id and destroy virus-infected cells
- Long-lived T/B cells chill in body for months or years and provide immunity
How long have microbes been around?
1st organism 3.5 B yrs ago (prokaryotes)
2.5 B yrs ago Eukaryotes came along (1 B yr after ^)
1 B yrs ago got multi-celled organisms (1.5 B yr after ^)
500M yrs ago development of brain (0.5 B yr after ^)
475M yrs ago life moves to land
250M yrs ago we get mammals
150K-200k yrs ago humans showed up
If you imagine Earth began as a single day…..
Microbes appeared at 5 am
Dinosaurs appeared at 10pm
….. humans appeared seconds before midnight
Archaea
- When 1st discovered 1977, thought to be bacteria
- exists in extreme (original thought) and less extreme places
- Humans have low lvls of archaea, don’t know importance
- Statins and Metronidazole eliminate them
3 kingdoms
- Bacteria
- Archaea
- Eukaryotes
What is considered Prokaryota?
Bacteria
Archaea
What is considered Eukaryota?
Plantae
Fungi
Animalia
Protista
Plantae info from tree of life
- contain chlorophyll, necessary for photosynthesis
- cell walls made of cellulose, fixed in one place
Fungi Info from tree of life
- usually motionless, absorb nutrients
- inc mushrooms, molds, and yeasts
Animalia info from tree of life
- most complex organisms on earth
- divided into vertebrates and invertebrates
Protista info from tree of life
- single celled organisms that have nucleus
- usually live in water
- made up of protozoa, unicellular algae, slime molds
- ex include algae, paramecium, amoeba
Bacteria inform tree of life
- single celled organisms that don’t have nucleus
- more forms of bacteria than any other organism on earth
Archaea info from tree of life
- bacteria with internal membranes
6 groups of pathogens
- Bacteria
- Viruses
- Fungi
- Protozoa
- Parasites
- Prion proteins
Order of Dec - Inc complexity
Viruses - Bacteria - Fungi - Parasites
Goal of viruses
Viruses exist to make more viruses
Virus structure
- core of RNA or DNA enclosed in capsid, or protein coat
- Glycoprotein envelope surrounds the capsid
- surface proteins inserted into envelope, help attach to host cell