General Exam IV Qs Flashcards
What is the defining organelle of euks?
(and what it contain?)
The nucleus!
Contains genomic DNA
What is the role of the nucelus?
Stores and protects genetic information, regulated expression, maintains it and so forth
-also forces spatial and temporal separation of transcription and translation
Bacterial gene expression:
what happen go!
(bonus for how different from euks)
-purple chain mRNA
-RNA polymerse main circle
-ribosome second big circle (ribosome will attach and start transcbing)
-growing peptide
9 RNA polymerases
-blobs at top are ribosomes and peptides theyre producing
-transcriptiona nd translation happening at same time messenger RNA is being synthesized
dear god do see the slide Unit III pg 4
Gene expression in a euk cell:
Transcription and
Translation: __________
and ___________
separated”
Transcription and
Translation: spatially
and temporally
separated”
For Gene expression in euks, what occurs in the nucleus and what occurs in the cytoplasm?
Transcription and Processing occur in the nucleus
Translation occurs in the cytoplasm
Describe transcription in euks
(where happen, and what make?)
Occurs in Nucleus
makes pre-mRNA (bacs dont do this)
Describe Processing (in gene transcription) in euks
(where happen, and what make?)
in nucleus,
makes mRNA,
mRNA reads
5’-cap
5’ (backwards G)———- 3’ (poly A tail, added by polyA polymerse, As not encoded in DNA)
Protein looks for those 3 backwards Gs
Both must be there to help them become mRNA
There are sections of exons in the sequence, and introns
The introns then gotta be removed (splicing)
So then exons are joined together to form coding sequence
5’ cap
-poly A tail
-removal of introns (all three happening at same time)
**do see slide Unit III pg 5
Are exons or introns removed before the remaining join together to form the coding sequence?
(bonus for the name of this event)
The introns then gotta be removed (splicing)
So then exons are joined together to form coding sequence
Describe Translation in euks
(where happen and what is synthesized?)
Occur in cytoplasm
Translation -> proteins synthesized!
DNA scattered through nucleus, there’s a nucleolus, area of intense transcription activity
-nucleoolis appears as large stain, due high trsanscription to ribosomal proteins
(do review slide for visual, unit III pg 5)
What is the nucleolus?
(do what and look like what on microscope slide?)
area of intense transcription activity
-appears as large stain, due high transcription to ribosomal proteins
How does a euk nucleus package its DNA?
(bonus for how bacs do it)
Use of histone protein complexes
forms a histone octomer (2 units each)
one additional histone
-bacs use (something omg sorry I forgot!) cations!
Histone proteins form an _________
octomer
Histone proteins form an octomer,
how many times does DNA wrap around this octomer, what is this called, and what attracts DNA to the octomer?
A lot of positively charged amino acids
-DNA naturally attracted
-DNA is wrapped around octomer to form nucleosome (wraps twice)
Name for histone octomer/DNA complex?
Nucleosome
How many bps of DNA make direct contact with the histone proteins (core)?
~160 base pairs of DNA make direct contact with the histone proteins (core)
Name of histones, and which one is unique?
(how many form the main octomer complex?)
H2A-
H2B-
H3-
H4-
H1- special, not in the main complex, binds at the conjunction where one strand comes in/out to twist a little bit
Nucleosome:
What is this?
and ~how many bps will one form?
basic unit of DNA packaging
-About every 200 base pairs, another nucleosome will form
Why do all this histone business?
-All done to make DNA shorter, you gotta make it shorter
What’s special about H1 histone protein?
(hint: histone not in the complex)
Histone H1 binds at the conjunction where one strand comes in/out to twist a little bit
“11nm fiber”
the 11nm fiber is kinda first stage of supercoiling of DNA (after nucelosome complexes of histone proteins and DNA form), later forms the 30 nm fiber
What little structure enables formed nucleosomes to reach out and coil together tightly?
(bonus: forming the what?)
-There’s a little tail protein branching out from the nucleosomes so they can interact with each other and pull tighter forming the 11nm fiber
Unit III pg 7
Why called 11nm fiber?
the diameter of the fiber structure formed by the coiling and packing of nucleosomes in the process of DNA compaction. It be one of the early stages in the hierarchical organization of DNA
11 nm fiber then compacts further to form the _______
30 nm fiber,
11nm fibers associate with each other and coil up together to from the 30 nm fiber (diameter)
Then protein scaffold formed to make look like WWWWWWW (sorta, review slides
Unit III pg 7
Finally, 30 nm fiber is condensed to what structure?
Packing ratio how many times shorter?
Eventually that loop gets fully packaged down to mitotic chromosome,
packing ratio ~8,000x shorter
Starting with strand of DNA, then adding histones etc, describe the levels of compaction
(in euks)
-DNA wraps twice around octomer of histones to form nucleosome (H1 at end for twisting outside complex)
-nucleosomes be pulling each other near with little tail proteins forming the 11nm fiber
-The 11nm fiber then coils tightly to form the 30nm fiber
-Finally, the 30 nm fiber then compacts to form mitotic chromosome
(packing ratio ~8,000x shorter )
Nucleur pore:
What it do?
-very tightly controlled protein complex that makes the gate
-usually closed, needs ATP to open it up, only does that when mature RNA knocks on the door
**review slides omg unit III pg 8
Name of the guys that carry things in and out of the nuclear pore?
-exportons and importons will bind and carry things through the pore
Nuclear pore/Nucleus?:
What is the physical structure?
(hint membranes, how many and look like what)
two membranes: between each nuclear pore, interconnected like pancake that folded
-Perinuclear space in the middle
-lining the inside of membrane nuclear lamina (made of lamins long protein filaments that are interwoven)
This one is cloth like, lining the inside, maintaining integrity
What is the lining of the inside of the nucelus’s like/composed of?
(right outside/inside depending on perspective of inner membrane I think????)
-lining the inside of membrane nuclear lamina (made of lamins long protein filaments that are interwoven)
This one is cloth like, lining the inside, maintaining integrity
unit III pg 8
Rough endoplasmic reticulum-
Found where, covered in what, and do what?
-Found right outside nucleus
-covered in little dots of ribosomes
-just an extension of the nuclear membrane
-Very different proteins and functions to the nucleus (proteins about translation, inside nucleus about protecting the DNA)
Mitochondrion: (singular)
basic components/function
-blue stuff inside mitochondrion: matrix
-pink infoldings of membrane are cristae (infolds bc it gives more surface area for the ATP synthesis)
-want as many proteins in inner membrane as possible to make that ATP
-outer membrane is stuff sac like for sleeping bag
**see unit III pg 12
What is the membrane structure for a mitochondrion?
Double membrane structure (not connected, cant take a stroll inside like the double nuclear membrane)
mitochonrion has its own __________
and how many are usually found in each cell??
genome- singular circular chromosome
-each cell has a lot of mitochondria (skin couple hundred, muscle thousands probably)
How do mitochondrions replicate?
(similar to how what other dudes do it?)
-most organelles tied to mitosis
BUT mitochondria can replicate autonomously whenever it feels the cell needs more energy
-replicates automonously within the cell to meet cellular energy demands
(bacs use binary fission to replicatie, same with mitochondria)
What are mitochondrions real specilaized at
-Specialized in energy production (ATP) via an electron transport chain
What does the mitochondrion electron transport chain for ATP synthesis look like?
**dear god do review slide unit III pg 13
-enzymes for glycolysis in cytoplasm (EMP, same as bacs)
2 pyruvtars to inside matrix to acetyl COA
NADHs go to electron transport chain to be recycled (inner membrane)
80% protein
-NADH drop off electrons at complex I, protons pumped outward to cytoplasm
-concentraiton of Hs is really low inside matrix, hence proton gradient is formed (even though outer concentration aint that high, higher than in matrix)
-Water binds H, and then only way the Hs can get back in is through ATP synthase, shaft turns, ATP produced
Where does the Krebb’s cycle occur in a mitochondrion?
-Krebbs cycle is in matrix in the mitochondrion
What’s the deal with the H’s in the mitochondrion ?
(what area most concentrated of the gradient, and what is the only way for Hs to get back in the cell)
-concentration of Hs is really low inside matrix, hence proton gradient is formed (even though outer concentration ain’t that high, higher than in matrix)
-Water binds H, and then only way the Hs can get back in is through ATP synthase, shaft turns, ATP produced
Chloroplasts! How many membranes they got?
3 membranes (outer and inner, and then thylakoids)
Thylakoid membrane holds the chlorophyll
Chloroplasts!
How many membrane, genome what, and replicates how?
3 membranes (outer and inner, and then thylakoids)
Thylakoid membrane holds the chlorophyll
-Chrolopast genome (circle like the bacs)
-replicate autonomously to meet energy demands of cell
What are chloroplasts totally fire at doing?
-Specialize in converting solar energy into cellular energy (ATP) and reducing power (NADPH) that can drive the fixation of carbon dioxide into organic molecules
20/10 would recommend reviewing the chloroplast membrane/cell structure
Unit III pgs 15-17
What is the stroma in a chloroplast?
-fluid-filled region encased by the inner membrane of the chloroplast.
(It be hostin’ various enzymes and substances that be crucial for the process of photosynthesis, the magical conversion of sunlight into energy.)
What’s the deal with the chloroplast proton gradient?
-Protons are pumped inward into the thylakoid (every protron accounted for and trapped in there)
-chloroplasts more efficient (than mitochondrions?)
What happens to the pH inside the thylakoid with the addition of light?
bonus: name of this inside space
-pH inside the thylakoid drops with addition of light
(becomes more acidic bc more H’s poppin in)
Thylakoid lumen (inside) Hs accumulate
How can H’s leave the thylakoid lumen ?
(chloroplasts)
ATP synthase channel only exit for Hs
ELectron chain for mitochondrions vs chloroplasts
Where the electrons come from? And how
-Electron that goes through mitochondrial ETC comes from NADH (from krebbs & glycolysis)
-Electron through ETC in chloroplast comes from H2O (releases O2)
How are electrons refilled with m n m energy in chloroplasts?
-Energy from sun charges up the empty electrons, fills up to then pump the protons
Photosystems II and I,
What happens, and who goes first?
**review slides, unit III pg 18
Photosystem II- absorbing photons and stripping electrons from water molecules, releasing oxygen in the process.
These energized electrons then go through electron transport chain.
Photosystem I- takes electrons that have traveled through the electron transport chain and further boosts their energy. PSI then passes these high-energy electrons to another carrier, eventually contributing to the formation of NADPH
protein pigment complexes
(they be catching the sunlight, giving enough energy to drive otherwise thermodynamically unfavorable reactions)
Do there be energy to be got from H2O?
Noo ain’t no energy to be got from H2O, they’re very low energy electrons
Photosystem II:
absorbing photons and stripping electrons from water molecules, releasing oxygen in the process.
These energized electrons then go through electron transport chain.
Photosystem I:
takes electrons that have traveled through the electron transport chain and further boosts their energy. PSI then passes these high-energy electrons to another carrier, eventually contributing to the formation of NADPH
What is Endosymbiotic theory?
The theory that nucleii mitochondria, and chloroplasts originated as separate cells who were inducted into cells to form euks
Nucleus probably used to be a(n) _________
(endosymbiotic theory)
Archea
-All nucleus related genes closest to archeal genes (DNA polymerase, RNA, histone proteins etc)
-Cytoplasm related genes closest to bacteria: (krebbs, cycle, glycolysis enzymes, genes in detoxification, stress response etc suff like that)
-Archea was so effective at protecting dna/expressing it etc, that eventually the archea lost their metabolic genes but retained nucleus-related genes
Why would archea develop into the nucelus?
-Archea was so effective at protecting dna/expressing it etc, that eventually the archea lost their metabolic genes but retained nucleus-related genes
-Suggestive evidence: archea have histones -> nucleosomes
-Archeal gene expression very similar to euks, different to bacs
-protein binds to promotor and start codon, then starts transcribing
-Archeal proteins:
-dna polymerase, rna polymerase, transcription factors
What is RNA polymerase like in euks and archea?
RNA polymerase in euks and archea is real blind, gotta be forced into there
(Bacterial RNA polymerase can find and do)
Endosymbiotic theory of how mitochondria and chrolorplasts came to be cell homies?
Endocytosis (they got engulfed)
What evidence supports endocytosis in endosymbiotic theory?
-Double membranes bb
(of the nucleus, endocytosis
-taken into an endosome **review slides if you can, basically cell is engulfing another cell for food usually) unit III pg 30
-outer membrane comes from host, inner membrane from bacterium (captured cell)
-engulfed bacterium loses some genes, so initially obligate parasites, but eventually established as an organelle
Idk man just talk about why make sense that chloroplasts/mitochondria were incorporated via endocytosis
(for ex. Mitochondria suddenly provided energy or nutrients if let cell live in engulfed state rather than chopping it down)
Mitochondrion and chloroplast, got engulfed through endocytosis
-bc engulfed bacterium better at making energy than host cell
DNA of mitochondria and chloroplasts look like what? (resemble what? Endosymbiotic theory)
-modern non-photosynthetic euks born due to the mitochondria poppin in (DNA is unique and circular like bacterial)
-mitochondria makes its own ribosomes, then it makes it own proteins and genes are transcribed using ribosomes (so we can use the SSU rRNA gene to sequence mitochondria)
Comes up as alpha-proteobateria
Closely related to bacteria called richettsia (intracellular parasite)
What is REFERED TO as first endosymbiotic event
when a eukaryotic cell engulfed a prokaryote
10/10 gotta review the endosymbiotic slides
unit III slides 30-34ish
Bacterial flagella vs euk flagella quick differences?
Bacs it’s a motor, flagella is external of plasma membrane
Euks it’s much more complex, flagella is technically intracellular structure (not outside membrane)
-Both grow from distil end, for bacs comes from inside hollow tube, for euks travels up side before joining to end
Eukaryotic flagella structure
(hint 4 main components, though one is empty space basically)
**see slides omg, unit III pg 43
Basal body- anchor
Plasma membrane- outside
Axoneme- middle thingy
Space for
intraflagellar
transport- yea
and cytoplasm down below ig
Axoneme-
who’s a part of this, and how it work?
-Dynein motors
-microtubules
-nexin
-inner sheath
who prolly the og chloroplasts?
Cyanobacs og chloroplasts
Do bacterial or eukaryotic flagella grow from the distil end?
-Both grow from distil end, for bacs comes from inside hollow tube, for euks travels up side before joining to end
-Dynein motors (little blue circles)
what are and do what?
the little feet of the dynein motors be walking along the microtubule (propels euk flagellar movement)
Little feet can move anolng microtubule, head is anchored
What powers euk and bacterial flagella to move?
-ATP powers euk flagella, motion is whipping back and forth (as dynein motors walk down, flips one over the other.)
-bac flagella proton gradient, propelling motion,
both grow through distil end but by different mechanisms
How many motors on a euk vs bacterial flagelluar motor?
Who is more rigid in structure, and who is most powerful?
-convergent evoltuon
-euk thousands of little motors, bac only have the one motor, euk more ridid structure so more power when it flips
For structure of axoneme rod (euks flagella)
unit III pg 44
What’s the deal with microbe euks and cell walls?
-Some always have a cell wall
-Some never have a cell wall
-Some only have a cell wall in certain life stages (like giardia wowow)
The Cell Wall:
made of what for bacs/euks
-peptioglycan (bacterial cell wall)
Euks:
-Cellulose
* Silica
* Chitin
* Carbohydrate-modified proteins
do most euk microbes have a cell wall?
-Not all euk mircobes have cell wall
-Most bacs do tho
Cell wall-
in euks and bacs, does what?
-support structure, shape to cell
-protects from chemicals /physical stresses/osmotic stresses
-hypertonic allows for full extension for plant cell, for ours they pop
What can euk cell walls be made from?
- Cellulose
- Silica
- Chitin
- Carbohydrate-modified proteins
Cellulose
(cell wall euk strucural compoent, look like what?)
- Linear polysaccharide chains of glucose linked via β
-1,4 glycosidic bonds
α-D-glucose β-D-glucose
β (14) glycosidic bond
CelluloseStarch
**see slide unit III pg 49-50
fibrils filled with microfibrules
Who has cell walls made of cellulose?
(and who in this group is the exception?)
Most algae have cell walls of cellulose
(Exception: Diatoms)
-also water molds and slime molds (microfungii)
Who has cell walls made of silica?
Diatoms bb
Silica
(cell wall euk structural component, look like what?)
silicon dioxide (see structure unit III pg 53)
-makes up sand, quartz, crystal and glass
-it’s real pretty
What is a frustule and what are the components?
(hint we’re talking about diatom silica cell walls)
frustule is glass shell of diatoms (like a petri plate)
epithecae- goes on top
hypothecae- is bottom component
not a cell wall in the traditional sense bc two components, but it is ~frustrating~ to try to break open for DNA
Chitin
(cell wall euk structural component, look like what?)
(it’s a bit of a beast goot luck)
-polysaccaride composed of subunits of modified glucose
-N-acetyl glucosamine (has acetyl group) NAG
Beta 1,4 linkages
-Chitin made up of NAG NAG NAG (my grandma killed my grandpa!)
(-half of makes up peptidoglycan)
-form structure similar to microfibule, lie across cell membrane
(review structure unit III pg 58-59)
What euks have cell walls of chitin?
-fungi, -yeast, etc
“what gives them their crunch”
Is chitin or cellulose a stronger cell wall? Why?
-Chitin stronger than cellulose bc hydrogen bonds
-form structure similar to microfibule, lie across cell membrane
What is this “NAG” that keeps appearing in chitin and made grandma kill grandpa?
N-acetyl-glucosamine
(NAG)
unit III pg 58-59
What euks have cell walls of Carbohydrate-modified proteins?
Protozoan parasites
HOWEVER most protozoa do not have cell walls
- Exceptions: Giardia, Cryptosporidium
and Entamoeba
-each have cell walls only during the
transmission (cyst) stage of their cell cycle
Carbohydrate-modified proteins
(cell wall euk structural component, look like what?)
hell just a protein with some sugars attached I think???
What’s the drama of the life cycles of these protozoan parasites, and at which stages do have cell walls?
(which are carbohydrate modified proteins btw)
cyst- transmission stage between hosts, has cell wall
Trophozoite or amoeba- disease causing stage, no cell wall (enhances interactions with host’s intestines)
Cytoskeleton
what is?
-Network of protein filaments, tubules, and
molecular motors that provide shape, internal
organization, and the means to move and divide for euk cell
What are the main 3 components of a euk cytoskeleton?
1) Microtubules
2) Microfilaments
3) Intermediate filaments
Microtubules- Composition and physical features
Polymers of α- tubulin and β-tubulin
* Subunits assemble into 24 nm fibers
Microfilaments-Composition and physical features
Polymers of actin monomers
* Assemble into two intertwined protofilaments
* Diameter: 7 nm helix
7 nm
Intermediate filaments-Composition and physical features
Composition: polymers of various proteins
* Examples: Keratins, Lamins, Vimentin, etc.
Proteins rich in α-helices
* Helical regions of monomers form dimer
* Dimers assemble to form tetramers
* Tetramers assemble both lengthwise and side
by side to form long, bundled, filaments
* Diameter: 8 to 11 nm
see slides unit III pg 77-81
Microtubules-
roles they play in the cell
form an intracellular organization network
Move vesicles, granules, organelles, and
chromosomes within the cell
* Direct vesicles to intended locations
-Dynein motor and microtubule
-Hold organelles in proper positions
**see slides, unit III pg 68-71
Microfilaments-
roles they play in the cell
Typically found at the periphery of the cell
where they help maintain cell shape
-typically found at the periphery of the cell
where they help maintain cell shape
Intermediate filaments-roles they play in the cell
-play primarily structural roles
Keratins:
-protect from mechanical stress
-anchor points inside cells
Lamins:
-nuclear lamina (looks like cloth) ((canvas in soccer ball))
-strenght and structural support
-membrane is only phospohlipids, mabsically olive oil, so need the lamina to line inside of nucleus so it cant just blip out
-mitotic spindle is a what?
(cytoskeleton component)
microtubule review slides unit III pg 70)
-seperates chromosmes during cell division
Microtubule forms the what in a euk flagella?
-Forms the axoneme of cilia and flagella (cilia same structure, just shorter and more numerous)
-each doublet two microtubules joined together
What type of movement do microfilaments cause/ aid in?
how do this?
- Cell movement (pseudopods)
“amoeboid movement”
done by extending
pseudopodium and then contracting
a star intermediate filament:
Keratin-
(cytoskeleton component component)
Keratins:
* Protect from mechanical stress
* Anchor points inside cells
a star intermediate filament:
Lamins-
-nuclear lamina (looks like cloth) ((canvas in soccer ball))
-strenght and structural support
(cell membrane is only phospohlipids, basically olive oil, so need the lamina to line inside of nucleus so it cant just blip out)
The Cytoskeleton question we’ve all been waiting for:
Do bacs got em?
-nah bacs don’t really have cytoskeletons, have some analogus proteins, but used for other things
So fungi- what’s their deal?
-heterotroph feeding by absorption, do not make or injest food, secrete
enzymes into the substrate
-Secrete hydrolytic digestive enzymes
-Digest complex organic substrates
-absorb soluble organic material
Ecological role of fungii?
-decompositon
Break down and absorb nutrients in environment
-dead plant material/corpses reaching out their little hyphae
-wastes of living organisms
What would happen without decomposers?
(hint what would be tied up forever?)
(((it’s not you in a dream with cate blanchett sorry)))
Crucial elements would remain tied up in organic matter, life would not be possible (carbon nitrogen, phosporus, sulfer)
the circle of life
Other ecological role of fungi beyond decompositon?
-fungal parasites (they attack before ya dead!)
-Absorb nutrients from living hosts, providing no benefit in return (usually agricultural diseases)
Fungal agricultural parasite Rusts are from what order/look like what?
Pucciniales
- Produce powdery rust-colored spores on
plant surface (reds and browns)
What do rusts cause?
cause plant deformities: -growth retardation (lack of nutrients)
-hypertrophy, galls, grows in the plant (fungi produce weird metabolites) grows all 3d secreting growth enzymes
-over expression of metabolites that resemble growth factors
Hypertrophy- witches broom
You’re a farmer and rusts be attackin your crops!
What they look like (the crops), and why problematic?
-Are among the most harmful pathogens to agriculture and forestry
-can lead to reduced yields, plant murder, people don’t buy ugly produce
Hypertrophy:
(Hyperplasia)
what is and caused by who?
Rusts- fungal parasites
-hypertrophy, galls, grows in the plant (fungi produce weird metabolites) grows all 3d secreting growth enzymes
-over expression of metabolites that resemble growth factors
What does Hypertrophy- witches broom look like and caused by who?
Crazy bird nest looking thing, caused by fungal parasite rust
Smuts-
what are, and do what to affected plant cells?
Looks freaky and grody
-fungal agricultural parasite
-produce spores inside the cells, kinda causing big blisters
-powdery fungal spores accumulate within blisters in plant tissues
-severe economic impacts on infected crops
Who are primarily affected by Smuts?
-primarily affects grasses (corn, wheat, sugarcane, and sorghum)
-Corn smut eaten as delicacy in south ameria “huilacoche”
What fungal class are Smuts?
Ustilaginomycetes
What fungal class are Rusts?
Pucciniales
Blights-
what are, and what does infection result in?
-parasitic fungi
-infection results in chlorosis, browning, then death of plant tissue
What fungal class are Blights?
get pranked, belongs to a variety of parasitic fungi
Blights were responsible for what Irish event?
-Great Irish Famine (1845-1849)
-Population dropped 25% from deaths and mass emigration from ireland
(usually blights are introduced, plants in native area know how to fock them up)
Famous USB blight in early 1900s!
(________ will ~not~ be roasting on the fire :( )
-American chestnut blight
-caused rapid wide spread die off of the American chestnut tree in early 1900s
-stops nutrients form getting to top of the tree
Tomato early blight-
looks like what?
-produces “bullseye spot”
Spores often survive and fall into soil
(spore looks like skinny legend grenade)
What fungal class is Ergot?
(sounds like dope homie you’d have in ancient rome)
clavicus
Who are primarily affected by Ergots?
grasses and
cereals [rye, wheat, oats, sorghum, barley]
(spore germinates in flowering grass/cereal;
mimics a pollen grain growing into plant ovary)
Ergots-
what are, and do what to affected cells?
-Plant disease caused by parasitic fungus
-Spore germinates in flowering grass/cereal;
mimics a pollen grain growing into plant ovary
Where do Ergot spores germinate? (resulting mycelium looks like what?)
-Spore germinates in flowering grass/cereal;
mimics a pollen grain growing into plant ovary
-resulting mycelium resembles seed grain
Problem with these ergot grain hijacking spores?
-easily overlooked
-ground into flour, baked into bread
-produces hallucinogenic compounds
oh no people be goin crazy
What happened to people who ate Ergot (what bread was especially often the culprit)
Rye bread,
-hallucinations, madness
-causes constrition of blood vessels in extremeities (feels like youre burning)
-results in gangrene of hands and feet
-St Anthonys was group of monks that were treating these people
Ergot may have caused french and witch catastrophies:
-salem witch hysteria may somewhat be due to crazy bread people be eatin
-in especially wet years where people where eating rye bread
-“The Great Fear” French revolution 1787-1799
A lot of irrational fear, seeing fake things, wowow
So basically, the fungi be responsible for people goin crazy sometimes
-Major historical changes might’ve just been caused by fungi
Human parasitic fungal disease: Athele’s foot
(Tinea pedis) and Ringworm
- Fungal infection of the skin by various fungi
(Trichophyton, Epidermophyton, Microsporum)
Human parasitic fungal disease: Yeast infections
caused by who, look like what?
(Candida albicans)
oh god it’s the fuzzy tongue thrush,
also C-difficillus
Athlete’s foot transmitted how?
-transmission direct contact (lockeroom floor avoid)
What usually causes yeast infections?
Candida albicans normally lives on the skin and
throughout the gastrointestinal and urogenital tracts.
What might cause it to suddenly become a problem?
Antibiotic use, throwing off microbiome balance
Fungal Mutualists-
-symbiotic relationship between a fungus and another organism wherein both members benefit
Leaf-cutting ants-
ex of what?
Fungal mutalism
Whats the story of the leaf cutter ants and their fungal farms?
Ants cut leaf sections from suitable plants
* Carry leaf sections back to nest
* Feed the leaves to fungal “farms
Leaf-cutting Ants
* Fungus produces specialized hyphae tips rich in
proteins and carbohydrates
With leaf cutter ants and their fungal farms, what does each benefit from?
fungus produces specialized hyphae tips rich on proteins and carbohydrates (only thing ants eat)
-fungi cannot survive without the ants (they bring it the food)
-ants depend on food and detoxification of compounds in plants
Ruminants-
ex of what?
(and found where)
fungal mutualist
found in the rumen, a large stomach chamber that serves a fermentation tank
Ruminants (fungal mutualists) contain fungii of what phylum?
-Contains fungi (phylum: Chytridiomycetes) along with bacteria and protozoa
What are the benefits to the ruminants (fungi) and cows?
-symbionts digest cellulosic plant material and release nutrients beneficial to host
-cows would die of malnutrition otherwise
Lichens can be described as:
(something like our Utah ancestors)
Pioneer organisms in harsh environments
-(after fires, one of the fastest things to come back)
-Lichens be growin on the lava
What is a lichen?
(looks like what?)
fungal mutualists
(between a phototroph and a fungus)
**review slides, looks like tennis balls in very organized yarn
what types of fungi pair with a photoautotroph to form a lichen?
(Abs)
-Ascomycetes and basidiomyces and a phototroph)
Describe the structural components of lichen:
-Cortex: fungal hyphae
-Green algae or cyanobacteria
-Loosly packed hyphae
-Rhizines: anchoring hyphae (anchor it to the rock, secrete acids that dissolve the rock, and then transport the minerals to the green algae)
What do the fungus and photoautotrophs gain in their lichen mutualistic relationship?
-Mutualistic relationship-
Phototroph provides:
-sugar and nitrogen fixation
Fungal provides:
-protection and cohesion
-water retention
-mineralization (fertilizer)
What is an Endophyte?
and do what to/for the plant?
(hint fungal mutualist in plants)
fungi or bateria that live inside plant
-produce toxins that deter herbivores
-produce molecules that hold onto water, increase plant tolerance to heat and drought
-protect plant from pathogens
Do all plant species cultivate fungal mutualists?
Yes
Mycrorrhizae-
what are, and what does each party contribute?
-mutually beneficial relationship between fungi and plant roots
-fungi partners improve solubilization and delivery of minerals to the plant
-plant partners provide organic nutrients
-fungus fertilizes the plant, the plant provides the sugars (energy)
Ectomycorrhizal associations-
-sheets of hypae over root, don’t go into cells, grow around cells, leading to more direct delivery system.
Arbuscular mycorrhizal associations-
Looks like little trees growing into the cells
-fungi extend branching hyphae through the plant cell wall into tubes formed by invagination of the plant cell plasma membrane
-Haustorium extension right up against membrane, protruding into cell, exchanges nutrients with plant host
What are the two types of Mycorrhizal associations?
Ectomycorrhizal associations-
&
Arbuscular mycorrhizal associations-
Some beneficial roles of fungus to humans?
Food & medicine
Examples of fungus as foods for humans?
-edible mushrooms
-ripened cheeses: blue cheese, camembert, brie
-miso, tempeh and soy sauce
-Baker’s yeast and brewer’s yeast
Examples of fungus as medicine for humans?
(there are many, bless you for your efforts)
Antibiotics:
-compounds produced by soil bacteria to gain an advantage when competing for food, water, and other limited resources
-Kill or inhibit the growth of bacteria
-Pennicllin
-cephalosporins
-streptomyces
Other drugs:
-immune suppressants
-inhibit organ rejection
-Statins
-lower density lipoproteins
Ergot alkaloids
-lower blood pressure
-promote uterine contractions
-counteract migraines
Yeast-
what does this describe?
-the single celled form of a fungus
Filamentous-
what does this fungal characteristic describe?
describes the multicellular form of a fungus
-most prevalent form of fungi
-typically form a network of tiny interconnected filaments
What is the most prevalent form of fungi?
Filamentous-
Can some fungal species exist as yeast and filamentous?
yep
Hypha-
what are? (fungal structure)
-single fungal filament
-consist of tubular cell walls surrounding the plasma membrane and cytoplasm of the fungal cells
Many fungal hypha are referred to as what?
hyphae
What do all hyphae make up?
the mycelium – the body of the fungus
What is the mycelium?
-the body of the fungus
-Whole interwoven mass of hyphae
-mycelium- singular, mycelia is plural
What does the mycelium do?
-infiltrates the material on which the fungus feeds
-maximizes surface-to-volume ratio to make feeding very efficient
-just one cubic cm up to 1 km of hyphae can be there (secreting digestive enzymes)
What is the septum?
(fungal talk here)
Septum- cross-wall that divides hyphae into cells
-septate (septa gaps are huge pores)
Typically fungal septa have pores large enough to allow what to flow through from cell to cell?
(a couple things, things you’d want to share with the neighbor cell homie despite the separation ((septa)))
ribosomes, mitochondria, and nuclei to flow from cell to cell.
Coenocytic fungii are also referred to as what?
super-celled
-Aseptate fungal hyphae
Entire mycelium is one “super cell”
Coenocytic fungi-
what are, consist of what
fungi that lack septa (whole body is continuous cytoplasm)
-consists of continuous cytoplasmic mass having hundred or thousands of nuclei
what do coenocytic fungi result from?
(hint: process without something)
repeated rounds of mitosis without cytokinesis
Spore-
reproductive structure
Characteristics of spores:
-adapted for dispersal and survival
-UV resistant, resistant to drying out
-cell wall made of chitin
-may be generated asexually or sexually
-can survive for a long time
Is spore dispersal a big event?
Usually I think?
Depends, but some species can produce and release billions of spores in a single dispersal event
Name of spores formed sexually vs asexually
(and what process forms each?)
Mitospores: geneterated by mitosis (mighty mito mitospores) (asexual)
Meiospores: generated by meisosis (sexual)
What spurs a spore into action, and what does that look like?
(once land in) will germinate in moist, nutrient rich places, to then produce a new mycelium
Germination-
fungi spore growing happily in moist, nutrient rich place to produce a new mycelium
Pheromones-
what are?
Sexually signaling molecule
What do fungi do with pheromones?
(leads to what kind of union?)
-Secreted by fungal hyphae
-bind to cellular receptors on potential partners
-trigger growth of hyphae toward the source
-Results in cellular fusion between the two compatible partners (plasmogamy I think??)yes it’s plasmogamy
What secretes pheromones in fungi?
hyphae
Do fungi have sexes and gender?
Yes sex, no gender hehe
-not male and female, refer to them as “opposite mating types”
just have different versions of reproductive genes
(pheramones and pheromone receptors)
Common designations: mat a vs mat alpha
Plasmogamy-
what is this, and makes what?
the sexual union of two haploid parent mycelia (both haploid) Referred to as heterkayotic cells, because two genetically different nuclei are in the same cell
-resulting cell not diploid
Are cells (resulted from plasmogamy) diploid since two n’s?
-NOT 2n (diploid) they are n+n heterkayotic
Do cells resulting from plasmogamy usually stay heterokaryotic for a while or do the nucelii tend to quickly fuse?
-can spend up to centuries as heterokaryotic cells
Karyogamy-
what is, and does usually happen fast?
-fusing of two nuclei in a heterokayotic cell
-may occur hours days or centueis after plasmogamy
-temporarity produces a diploid cell: a zygote
Karyogamy temporarily produces a what cell?
Diploid
(bc the two nucs do be fusin’)
How do filamentous fungi tend to reproduce?
(ace or sex, spores or buds?)
-many fungi reproduce sexually or asexually
-some are only known to reproduce asexually
-most filamentous fungi propagate by producing spores
By default, fungal hyphae are what?
Haploid
homie im gonna say yolo this freaking “typical filamentous fungi reproduction cycle”
review notes (highlighted purple) in conjunction with unit III fungi slide 58
Reproduction in Yeast-
budding
Reproduction in yeasts-Can occur sexually or asexually?
Usually asexual, but can be sexual (it’s a bit tricky to get all lined up though)
Describe Asexual reproduction in yeast:
Asexually- nucleus replicates (mitosis)
-bud forms on side
-one nucleus migrates into bud
-two cells eventually separate
(can see from scars how many babes have been babed)
Can yeasts reproduce by spores?
-no spores, most yeasts reproduce by budding, no spores created
(can try to survive harsh conditions by sporylation, but this is survival not reproduction ig)
Describe Sexual reproduction in yeasts
Secrete pheromones and aren’t filamentous
If laying side by side then they’ll develop a bud on each side facing each other
Called Shmoo
Two shmoos will join together (diploid), plasmogomy, followed by karyogamy, mitosis then follows (despite the sexual union)
Budding again with daughter cell coming off (persists as diploid with no spores being produced)
Throw out some crazy numbers for how often yeasts use sexual/asexual reproduction and spore formation-
1% of time sexually, 99% of time asexually
0.01% spores
What does yeast sporulation look like?
(happen when?)
Sporulation can occur but only in high stress situations (survival technique)
-each nuclei gets a cell wall basically to become haploid cell
Brief fungal origin story-
-Fungi probably colonized land before plants did
-in pools with algae cyanobacs and fungi
-from the earliest fossils of plants we see fungi there
-as soon as land plants developed, fungi quickly established symbiotic associations (early plants had no roots) fungi helped then extract nutrients form the soil
-400 million years ago show evidence for arbuscular mycorrhizal relationship (goes into the cell,a nd makes direct contact with plasma membrane)
How did fungus help out ancient plants?
-Fungal patterns helped transfer soil nutrients to the early land plants via extensive mycelia (they didnt have roots back then OOf)
What do fungal DNA sequences tell us about their parentage?
-DNA sequence of fungi shows closest relatives would’ve been unicellular ancestor with one flagella, leading to todays flagellated protsits, fungi, and us
Clade-
group of modern organisms that share common ancestor and all its linal descendants
-Flagellated protists and fungi a clade
-all fungi could be a clade etc
Opisthokont- shows we have common ancestor with fungi (clade we are in)
Is protist a formal term?
Nar, since they aren’t closely related, but for convenience call them protists because they’re all euks who arent plant animal or fungus
Are protists a closely related grouping of organisms?
NO
“genetic and morphological studies have shown some protsits more closely to related to animals, plants, fungi, than to other protists
-protista kingdom abandoned bc they’re not a closely related group
What are the 4 EUK super-groups?
Excavata- all protists
SAR Clade – all protists
Archaeplastida- algae/land plants, and protists
Unikonta- fungi, (us) animals, protists
What is the name of the clade that contains Animals, flagellated protists, and fungi? (Spell it correctly)
Opisthokont
