Unit 4: Protists, Bacteria, and Viruses Flashcards
Dirty Kinky People Can Often Find Great Sex
Domain Kingdom Phylum Class Order Family Genus Species
Dirty
Domain
Kinky
Kingdom
People
Phylum
Can
Class
Often
Order
Find
Family
Great
Genus
Sex
Species
Who developed the taxonomic categories?
Carolus Linnaeus
Our system of naming uses two names–what’s that called?
Binomial nomenclature
What two taxonomic categories do we use in our naming system?
Genus and species
How are the species names written
Genus species
e.g. Canis latrans
What do protists have in common?
Mostly unicellular
All eukaryotes
Mostly live in water
What do animal-like and fungus-like protists have in common?
They are heterotrophs
What do we actually call consumers?
Heterotrophs
What do we actually call producers?
Autotrophs
How do animal-like protists get their nutrients?
They ingest to digest;
they are consumers or parasites.
How do fungus-like protists get their nutrients?
They digest outside and absorb nutrients.
How do plant-like protists get their nutrients?
They are autotrophic.
What is the “real” definition of a protist?
Any eukaryote that is not a plant, animal, or fungus
What’s another name for animal-like protists?
Protozoa or protozoans
Basically, what are the plant-like protists?
Algae
Basically, what are the fungus-like protists?
Decomposers
What’s that organelle that looks like a star?
The contractile vacuole
How does an amoeba move?
Using pseudopodia, false feet, which are extensions of the cytoplasm
How does a paramecium move?
Moves using cilia
How does a plasmodium move?
It doesn’t
What do amoeba eat?
Bacteria and other protozoans
How does an amoeba eat?
By surrounding and engulfing it; the food goes into the food vacuole with digestive enzymes.
Which organelle removes excess water?
The contractile vacuole
What does the contractile vacuole do?
Removes excess water
Where do amoeba live?
Ponds or slow stgreams
What do we call the amoeba-engulfy way of eating?
Phagocytosis
phago- devour
cyto- recepticle
sis- ing (showing action)
What do amoeba do when conditions are unfavourable?
They become dormant by secreting a protective membrane.
What does “dormant” meant?
Metabolism slows; neither making nor using energy
What do we call the protective membrane that amoebas secrete when conditions are unfavourable?
Cysts
How do most protists reproduce?
Mitosis
What sickness can amoeba cause in humans?
Amoebic dysentery from contaminated water
Where are paramecium found?
Mostly in ponds and streams
What do paramecium eat?
Bacteria and protozoans
How does a paramecium eat?
The food comes in through a mouth pore, is moved into a gullet, and forms a food vacuole.
What is the rigid outer membrane of a paramecium called?
Pellicle
What are the advantages/disadvantages of the pellicle?
Can’t change shape, but offers more protection
How does a paramecium remove wastes?
Through the anal pore
What’s the kicker with paramecium?
They have two nuclei: macro- and micro-nucleus, used to reproduce sexually.
What does the macronucleus do in paramecium?
The normal job: controls protein synthesis, digestion, respiration, etc.
What does the micronucleus do in paramecium?
Used during conjugal visits
How do paramecium reproduce?
Two ways:
- Asexually (binary fission)
- Sexually (conjugation)
How does sexual reproduction work with paramecium?
Two paramecia join at the mouth pore; they then swap haploid micronuclei (that have undergone meiosis); these then form the macronuclei of the daughter cells after cells separate and each divides.
Which protist causes malaria in humans?
Plasmodium
How is plasmodium spread?
Through the anopheles mosquito
What’s a parasite?
An organism that lies on or in a host organism and causes harm to that organism
What’s a vector?
An organism that can carry a parasite and is responsible for infecting other organisms with that parasite
What are the three kinds of symbiosis?
Mutualism
Commensalism
Parasitism
What are the symptoms of malaria?
Fever, headache, vomiting, and other flu-like symptoms
How do plasmodium live in humans?
They live inside the bloodstream, infect liver cells and then red blood cells, clog blood vessels and destroy red blood cells, leading to death if not treated
Why are plant-like protists so bloody important?
They produce shit tons of oxygen
Are plant-like protists considered multi-cellular organisms?
No. Algae form filaments, which is why we can see them, but they are not true multicellular organisms because they don’t work together
What are three examples of plant-like protists?
Diatoms
Spirogyra
SOME euglena
What are euglena?
Mostly animal-like but occasionally plant-like protists
How do euglena move?
With a flagella
What physical feature puts euglena apart?
They have an eyespot.
What does the eyespot on a euglena do?
Senses light so it can places to photosynthesize
When do euglena become animal-like?
When they are kept in the dark and need to get energy as consumers
What are the main producers of oxygen in the oceans?
Diatoms
Why are diatoms so important in the ocean? (apart from the oxygen thing)
They are an important food source for marine animals, i.e. plankton
What sets diatoms apart physiologically?
They produce thin cell walls of silica
What do we call pond scum, aka multicellular algae?
Spirogyra
Spirogyra have bucket loads of what?
Chloroplasts
Are spirogyra multicellular organisms?
No, they are long filaments of cells connected end-to-end
Where do you find spirogyra and what do they look like?
They appear as slimy green mats on the surface of clean, nutrient-rich water; literally, this is pond scum
What is the common name for fungus-like protists?
Water mold
How do fungus-like protists work?
They form a mesh of nutrient-absorbing filaments.
Define autotroph.
Producing organic compounds (food) from CO2, H2O, and sunlight. Basically: does photosynthesis.
How do euglena get their nutrients?
Photosynthesis and consumption of bacteria and smaller protists.
Why is controlling the vector important to controlling the disease?
The vector transmits the disease
What are the pros of DDT?
An effective control of malaria vector, i.e. kills the shit out of mosquitos
What are the cons of DDT?
- It kills the shit out of everything else.
- Damages the ecosystems
- Bio-accumulates and produces disease in higher-order consumers
What are the 8 main parts of bacteria/archaea?
Cell wall Capsule Plasma membrane Cytoplasm Flagellum Pilus DNA Ribosomes
What are the five types of archaea?
Chemosynthetic Photosynthetic Halophiles Methanogens Thermophiles
What are chemosynthetic bacteria?
They use chemicals to obtain energy and are found on the ocean floor.
What are thermophiles?
Bacteria that live in hot springs, lava, etc.
What do we call the group of bacteria that do cellular respiration without oxygen?
Obligate anaerobes
What are halophiles?
Bacteria that live in salty environments
What are methanogens?
Bacteria that live in animal guts and sewage treatment plants, and produce methane gas
How do most bacteria obtain energy/nutrients?
They are heterotrophs
What do we call bacteria that get food from living organisms without killing them?
Parasites
What do we call bacteria that get energy from dead organisms (decomposers)?
Saprophytes
What is another name for photosynthetic bacteria?
Blue-green algae
What do some bacteria form when conditions are unfavourable?
Endospores
What happens when bacteria form endospores?
A thickened cell wall forms around DNA and small amount of cytoplasm; the rest of the cell disintegrates
What are bacteria resistant to when they form endospores?
Resistant to drought, heat, radiation, acids, and disinfectants
How long can bacteria stay as endospores?
1000 years
What are sphere-shaped bacteria called?
Cocci
What are rod-shaped bacteria called?
Bacilli
What are spiral-shaped bacteria called?
Spirilli
What do we call bacteria that cluster?
Staphylo
What do we call bacteria that chain?
Strepto
How do bacteria stick together?
The sticky capsule!
Which virus causes shingles?
Varicella zoster virus
What are the symptoms of shingles?
A painful rash that develops on one side of the face or body. The rash forms blisters that typically scab over in 7 to 10 days and clears up within 2 to 4 weeks. Other symptoms: - Fever - Chills - Headache - Upset stomach
How is shingles transmitted?
4 points
- Shingles cannot be passed from one person to another.
- The varicella zoster virus, can be spread from a person with active shingles to another person who has never had chickenpox. In such cases, the person exposed to the virus might develop chickenpox, but they would not develop shingles.
- The virus is spread through direct contact with fluid from the rash blisters caused by shingles.
- A person is not infectious before the blisters appear. Once the rash has developed crusts, the person is no longer contagious.
What is the best treatment/prevention for shingles?
There is a shingles vaccine and people over 60 are recommended to get it.
There are several antivirals for treatment, but to be effective, they must be started as soon as possible after the rash appears.
Pain medicine, calamine, and oatmeal baths can help with the pain and itching.
Which bacteria cause ulcers?
Helicobacter pylori
What is the treatment/prevention for H. pylori?
Antibiotics for treatment.
Since the vector is unknown, there are no prevention recommendations.
How is H. pylori spread?
It is not known how H. pylori is transmitted or why
some patients become symptomatic while others do
not. Contaminated water sources and endoscopes are possible culprits.
What are the symptoms of H. pylori infection?
A gnawing or burning pain in the epigastrium, especially when stomach is empty. Less common: - Nausea - Vomiting - Loss of appetite
How do bacteria reproduce?
Mostly asexually
What’s it called when cells split?
Binary fission
What’s up with the DNA in bacteria reproduction?
There’s a single strand of DNA that gets replicated; there are no chromosomes.
What’s up with bacteria conjugation?
Plasmids are transferred through a cytoplasmic bridge formed by a pilus
What’s a plasmid?
A small, separate, circular piece of DNA
What are some advantages to bacteria?
- They are part of food for us
- Symbiotic relationship with plants
- They decompose waste
- They recycle nutrients (complete the loop)
- Help digest food
What are some disadvantages of bacteria?
- Kill our species in the millions
- Destroy food and property
- Create general unpleasantness such as bad breath, acne, etc.
What are the basic parts of viruses?
They are basically just DNA/RNA surrounded by protein
What is the protein coat of a virus called?
Capsid
What are two other things that a virus might have?
Enzymes to help it inject DNA into the host, and an envelope formed of little bits of membrane they steal from the hoset.
Why aren’t viruses alive?
four points
- They don’t do homeostasis
- They do not do cellular respiration
- They do not grow or develop
- They cannot reproduce on their own
What life-like qualities do viruses have?
- They do reproduce, just not on their own
- They evolve/mutate
- They have limited movement
What are the four types of viruses?
Bacteriophages
Adenoviruses
Retroviruses - RNA viruses
DNA viruses
What are bacteriophages?
Viruses that infect bacteria; they can be considered helpful because they kill bacteria that can harm us
What are adenoviruses?
Infects animals; causes eye infections, common colds, hepatitis, etc.
What is the structure of an adenovirus like?
It has a 20-sided protein cot with a spike at each corner
What are retroviruses?
RNA viruses that have an enzyme called reverse transcriptase which converts RNA to DNA inside host cells
What do retroviruses cause?
Influenza, rabies, AIDS
Which viruses have lipid envelopes?
RNA and DNA viruses
What do DNA viruses cause?
Smallpox and herpes
What are the two virus cycles in bacteriophages called?
Lytic and lysogenic
Which cycle kills the host cell?
The lytic cycle
What are the five stages in the lytic cycle?
- Attachment
- Penetration
- Replication + Synthesis
- Assembly
- Release
What does “lysis” actually mean?
The “breaking” of the cell; BOOM!
How do the lytic and lysogenic stages differ?
There is no synthesis of parts in the lysogenic cycle; the virus basically remains dormant until the time is right, then BAM!
Why are viruses so difficult to treat?
If it’s not alive…then how do you kill it?
What’s the difference between prokaryotes and eukaryotes?
Prokaryotes have only a simple DNA molecule which (unlike in eukaryotes) does not coil into chromosomes and is not surrounded by a nuclear membrane.
What is the difference between archaea and bacteria?
Archaea are older and found in more extreme environments
What are cyanobacteria sometimes classified as plants?
They carry out photosynthesis: they fix carbon from CO2 into organic compounds and produce oxygen.
Describe binary fission
The DNA molecule of a bacterium is replicated and the two molecules are separated by membrane and wall material while it continues to grow. When it has almost doubled in size, the new membranes and walls between the DNA molecules are completed and two identical cells result
Why are bacteria important for our digestion?
They break down certain food molecules and produce vitamins, including vitamin K
What structure protects bacteria?
The capsule offers some protection against things like white blood cells
What is a bacterium’s capsule made of?
Sticky polysaccharides
What are the function of pili?
They help bacteria cling to surfaces, and sex pili enable conjugation
What kind of virus causes HIV?
RNA virus
What kind of virus causes genital herpes?
DNA virus
What kind of virus causes warts?
Adenovirus
What kind of virus kills bacteria?
Bacteriophage
What kind of virus causes influenza?
RNA virus
What kind of virus causes eye infections?
Adenovirus
What kind of virus causes polio?
Adenovirus
What kind of virus causes rabies?
DNA virus
What kind of virus causes cold sores?
DNA virus
Distinguish between the lytic and lysogenic pathways.
In the lytic pathway, the virus uses the host cells to reproduce, then kills the cell.
In the lysogenic cycle, the viral DNA is inserted into the host DNA molecule and is duplicated along with host DNA when cells divides.
What are the two main differences between the lytic and lysogenic pathways?
Viral proteins are made vs. not made
Cells are killed vs. not killed
Do viruses and bacteria cause disease in the same way?
No. Viruses hijack the host cell and prevent the cells from functioning properly, whereas bacteria invade human tissues and cause disease through the toxic substances they produce and release.