microbio test 2

What theory says that eukaryotic cells evolved when larger prokaryotic cells engulfed smaller prokaryotic cells?

What theory says that eukaryotic cells evolved when larger prokaryotic cells engulfed smaller prokaryotic cells?

endosymbiotic theory

What is the evidence for the endosymbiotic theory?

mitochondria

chloroplasts

What converts the energy of sunlight into chemical energy through photosynthesis?

chloroplast

What are long sheathed cylinder containing microtubules in a 9+2 arrangement?

flagella

What are shorter and more numerous than flagella and function in filtering, feeding, and motility?

cilia

What is an outermost boundary that comes into direct contact with environment?

-is usually composed of polysaccharides and it functions in adherence, protection, and signal reception

glycolax

What is rigid, and provides structural support and shape?

-fungi and most algae have a thick, rigid cell wall surrounding the cell membrane

-protozoa, only a few algae, and all animal cells lack this and have only a membrane

cell wall

What has a typical bilayer of phospholipds and proteins?

-serves as a selectively permeable barrier in transport

-also functions in adhesion, secretion, and signal transduction

cell membrane

What is a compact sphere, most prominent organelle of a eukaryotic cell?

-contains chromosomes

nucleus

What organelle synthesizes proteins and shunts them into the ER for packaging and transport?

-ribosomes on outer surface

rough endoplasmic reticulum

What organelle functions in processing, synthesis, and storage of lipids?

smooth endoplasmic reticulum

What organelle modifies, packages, and stores proteins?

golgi apparatus

What is the order of synthesis and transport?

nucleus->RER->Golgi->vesicles->secretion

What organelle is involved in intracellular digestion of food particles and in protection against invading microbes?

lysosomes

What are membrane-bound sacs containing particles to be digested, excreted, or stored?

vacuoles

What are vacuoles merged with a lysosome?

Phagosomes

What functions in energy production and storage (ATP)?

mitochondria

What kind of membranes hold the enzymes and electron carriers of aerobic respiration?

cristae membrane

What converts the energy of sunlight into chemical energy through photosynthesis?

chloroplasts

Outer membrane covers inner membrane folds into sacs called ___, stacked into ___

thylakoids, grana

What is composed of rRNA and proteins, and are scattered in the cytoplasm or on the RER?

ribosomes

What is the flexible framework composed of proteins, microfilaments and microtubules form network throughout cytoplasm and functions in structural support?

cytoskeleton

What kingdom has a majority unicellular or colonial; a few have cellular specialization

kingdom fungi

What are long filamentous fungi or molds?

Hyphae

What are round ovoid shape, and use asexual reproduction?

-has a cell wall and lacks locomotor organelles

Yeast

What are some examples of macroscopic fungi?

mushrooms, puffballs, gill fungi

What are some examples of microscopic fungi?

Hyphae and Yeast

filamentous fungi (molds) can have what kind of texture?

hairy, cottony, or velvety

What kind of hyphae digest and absorb nutrients?

vegetative hyphae

What kind of hyphae produce spores for reproduction?

reproductive hyphae

What is a chain of yeast cells called?

pseudohypha

fungal reproduction is primarily through ___ formed on reproductive hyphae

spores

What is formed by successive cleavages within a saclike head called a sporangium?

Sporangiospores

what are free spores not enclosed by a spore-bearing sac?

coonidiospores (conidia)

What are some examples of fungi's adverse impacts?

mycoses (pathogenic), allergies, toxin production

-destruction of crops and food storages

What are some examples of fungi's beneficial impacts?

sources of antibiotics, alcohol, organic acids, and vitamins

-used in making foods and genetic studies

What are eukaryotic organisms, usually unicellular or colonial, that photosynthesize with chlorophyll a?

Algae

What are unicellular eukaryotes that lack tissues and share similarities in cell structure, nutrition, life style, and biochemistry?

Protozoa

What type of algae are free-living in fresh and marine waters?

-they provide a basis of food web in most aquatic habitats

-produce a large proportion of atmospheric O2

-Dinoflagellates can cause red tides and give off toxins

-used for cosmetics, food, and medical products

plankton

What is a diverse group that lacks a cell wall, varies in shape, and most are harmless?

-most are unicellular, colonies are rare

-all are heterotrophic (make their own food)

-feed by engulfing other microbes and organic matter

Protozoa

Most of these have locomotor structures- flagella, cilia, or pseudopods

-exist as trophozoite (active stage)-motile feeding stage

-many enter a dormant stage during unfavorable conditions for growth and feeding-cyst

-mostly reproduce asexually (mitosis), some do produce sexually (conjugation)

protozoa

What are Trypanosomes (protozoan pathogen)?

pathogenic flagella

T. cruzi is what disease?

Chagas disease

T. brucei is what disease?

African sleeping disease

How are Trypanosomes transmitted?

they occur in the blood during infection by blood-sucking vectors

What are infective amoebas?

Entamoeba

What is the pathogenesis of Entamoebas?

ingested cysts germinate in the small intestine

trophozoites migrate to the large intestine and grow

they can invade the liver, lungs, and skin

common symptoms are gastro related

What are muticellular animals, organs for reproduction, digestion, movement and reproduction?

parasitic helminths

What are flat, have no definite body cavity; simple excretory and nervous systems?

-cestodes (tapeworms)

-trematodes or flukes

flatworms

What are round, have a complete digestive tract, and spines and hooks on mouth?

round worms

What is acquired through ingestion of larvae or eggs in food; from soil or water; are distributed worldwide, approximately 50 species parasitize humans?

parasitic worms

Who identified pathogens such as tuberculosis, cholera, and anthrax?

Robert Koch

Who were the two people that identified the filterable agent cause of certain diseases?

Friedrich Loeffler and Paul Frosch (1898)

What played a role in the evolution of Bacteria, Archaea, and Eukarya?

viruses

What is the ultramicroscopic range for measuring viruses and what microscope is used to measure them?

20nm up to 750nm; electron microscope

Whose basic structure consists of a protein shell (capsid) surrounding a nucleic acid core?

virus

Nucleic acid of the viral genome is either ___ or ___ but not both

DNA or RNA

Viruses lack what two things for most metabolic processes and for synthesizing proteins?

enzymes and machinery

The largest viruses average what size and what are 4 examples?

400-1,500 micrometers and mimiviruses, megaviruses, pandorviruses, and pithoviruses

Viruses are ____ ____ parasites because they need a host to survive.

obligate intracellular parasites

What are the two main parts of a virus particle?

1. covering (capsid and envelope)

2. central core (DNA/RNA and enzymes)

True or False: Viruses bear no resemblance to cells

true

What structure consists of regular, repeating molecules that give rise to their crystalline appearance?

-when purified, many can form large aggregates of crystals

crystalline nature

What is the capsid and nucleic acid together?

nucleocapsid

What are capsids made of identical protein subunits called?

capsomers

What are the two types of structural capsids?

Helical and Icosahedral

Describe the Helical capsid type.

continuous helix of capsomers forming a cylindrical nucleocapsid

Describe the Icosahedral capsid type.

three-dimensional, symmetrical polygon, can vary in number of capsomers

What is a naked virus?

A virus that lacks an envelope

Icosahedral viruses may or may not have an outer ____

-Rotavirus is a naked virus

envelope

A virus with an envelope occurs mostly in ______ cells and is acquired when the virus leaves the ___ cell

animal cells; host cells

The capsid/envelope serve to do what?

protect the nucleic acid when the virus is outside of the host cell

What are viruses that lack a typical capsid and are covered by a dense layer of lipoproteins and coarse fibrils

poxviruses

What have a polyhedral nucleocapsid along with a helical tail and attachment fibers?

bacteriophages

DNA viruses are usually ____ stranded but may be _____ stranded

double;single

RNA viruses are usually ____ stranded but may be _____ stranded and may be segmented in separate RNA pieces

single;double

ssRNA genomes ready for immediate translation are __________ RNA

-look like mRNA (they are camouflaged)

positive-sense

ssRNA genomes that must be converted into proper form are __________ RNA

negative-sense

What are three pre-formed enzymes required for viral replication?

1. polymerases (synthesize DNA or RNA)

2. replicases (copy RNA)

3. reverse transcriptase (synthesis of DNA from RNA HIV)

What are the three ways viruses are classified?

structure, chemical composition, and genetic makeup

What are the 6 phases in animal virus multiplication cycle?

1. absorption- binding of virus to specific molecules on the host cell

2. penetration- genome enters the host cell

3. uncoating- the viral nucleic acid is released from the capsid

4. synthesis- viral components are produced

5. assembly- new viral particles are constructed

6. release- assembled viruses are released by budding (exocytosis) or cell lysis

What is the host range?

spectrum of cells a virus can infect

What is the viral envelope that fuses directly with the host membrane by rearrangement of lipids?

fusion

What is it called when the entire virus is engulfed and enclosed in a vacuole or vesicle and once inside the virus is uncoated and nucleic acid is released?

Endocytosis

Where are DNA viruses generally replicated and assembled?

nucleus

Where are RNA viruses generally replicated and assembled?

cytoplasm

What contains the message for translation?

Positive-sense RNA

What must first synthesize positive-sense RNA?

Negative-sense RNA

What are mature virus particles constructed from?

growing pool of parts

What is it when the nucleocapsid binds to membranes which pinch off and shed the viruses gradually; cell is not immediately destroyed?

Budding/exocytosis

What is it called when the virus is released when the cell dies or ruptures?

Cell lysis or rupturing

What is it called when there is cell damage altering the microscopic appearance?

cytopathic effects

What are 3 cytopathic effects?

-disorientation of individual cells

-gross changes in shape or size

-intracellular changes (inclusion bodies)

What state can last weeks or a host's cells lifetime

chronic latent state

-herpes simplex virus

-herpes zoster virus (chickenpox and shingles)

Some animal viruses enter the host cell and permanently alter its genetic material resulting in ___

These viruses are termed ___, and their effect on the cell is called ___

cancer

oncogenic and transformation

What are mammalian viruses capable of initiating tumors?

oncoviruses

-Epstein-Barr virus

What are bacterial viruses called?

Bacteriophages

What cycle is the release a result of cell lysis induced by viral enzymes and accumulation of viruses?

lytic cycle

What are the steps in phage replication and what are they?

1. adsorption- binding of virus to specific molecules of host cell

2. penetration- genome enters host cell

3. replication- viral components are produced

4. assembly- viral components are assembled

5. maturation- completion of viral formation

6. lysis and release- the lytic cycle involved full completion of viral infection through lysis

   *occasionally virus enters a reversible state of lysogeny and its DNA is incorporated into the hosts genetic material

The viral genome inserts into bacterial genome and becomes an inactive ____- the cell is not lysed

prophage