Biol240: Eukaryotes

What is different about Eukaryotes than Bacteria or Archaea

membrane bound nucleus/contain organelles

are Eukaryotic cells usually bigger or smaller than archaea and bacteria?

bigger

Function of the Nucleus?

Contains the DNA of the cell and is the site for transcription

Function of the mitochondria?

Energy production (cellular respiration)

Function of Chloroplasts

photosynthesis (creates ATP), uses ATP created to fix carbon onto organic compounds

Function of Rough ER

protein synthesis (translation + protein folding)

function of Golgi apparatus

Modify, sorts and transports proteins

function of vacuole

storage and structure

function of lysosome?

digestion of macromolecules

function of peroxisome

digestion of fatty acids

function of hydrogenosome

production of hydrogen and ATP

What confirmation are the chromosomes in within the nucleus?

linear

purpose of nucleolus

creation of ribosomes

what comprises the secretory pathway?

ER and the golgi apparatus

Why are both mitochondria and chloroplasts considered "autonomous" ?

1 - each have DNA genomes, ribosomes, and transcription machinery

2 - they can replicate independendtly of the cell

3 - most of their proteins originate from their DNA

active vs passive transprt (diffusion)

uses energy vs doesnt use energy

Homeostasis

process by which organisms maintain a relatively stable internal environment (cell membrane accomplishes this)

purpose of cell wall

to help provide structure and protection

two types of eukaryotic cell wall materials

cellulose (beta 1-4 glycosidic linkages), chitin (NAG-NAG-NAG)

overall purpose of cytoskeleton

to help provide structure to cells

what are the three major pieces of the eukaryal cytoskeleton and what is each made out of?

microtubules (tubulin), microfilaments (actin), intermediate filaments (various proteins)

purposes of microtubules:

intracellular transport (nerves), separation of chromosomes in mitosis/meiosis (spindle fibres), cell movement (cilia and flagella)

purposes of microfilaments:

maintain cell shape, creates division furrow during cytokinesis, cell movement (in pseudopods like aeomebas)

purpose of intermediate filaments:

maintain nucleus structure, cell-cell interactions

what is the Axanian structure of the cilia in eukaryotic cells?

9 tubulin groups around the outside and 1 tubulin group in the middle (axoneme)

what causes cilia to move in eukaryotes?

when ATP is burned (kinesin uses ATP too)

What two pathogens can exploit the cytoskeleton?

HSV and Listeria

Polyphetic

a group that shows up many times on species tree (algae)

Monophetic

a group that only shows up once

What microorganism would be an easy, cheap tool to study eukaryotic structures/gene expression

saccharomyces serivisae

Chytridiomycota

early branching, "watermolds", Laurel Creek banks

Zygomycota

normal mold (find on bread)

Glomeromycota

extremely important for plants/trees (neural network under forests)

Ascomycota

"spore shooters" (fungi, yeast) can create weird looking mushrooms

Basidiomycota

"spore droppers" "club fungi" *can create normal mushrooms (stuff you would eat on pizza)

Protozoa

a very broad category of eukaryotic organisms, some are heterotrophic while others are photosynthetic, have different cell calls, mate differently, etc. (Amoeba proteus is part of this)

what microorganism is can be studies for a lack of mitochondria (also called Beaver fever)

Giardia Lamblia (genetically old)

What microorganism could be used as a model for studying ecology, cell motility, and cell-cell communication?

Dictyostelium discoideum (slime mould)

What microorganism fuses many cells into a continuous, multinucleate giant cell?

Physarum (slime mould)

What microorganism has two-flagella form good for studying eukaryal flagella biogenesis/function and are durable and easy to grow?

Chlamydomonas

All algae are:

photosynthetic (and have cell walls)

What happens with Algae in low pH?

they lose their flagella and grow it back when conditions are right again

two ways eukaryotes mate:

sexually and asexually

What is Mitosis

The division of a eukaryotic cell, creates two identical daughter cells from one original

What is Meiosis

A way to produce 4 haploid gametes from 1 cell. Involves two different stages of cell division as well as a stage of genetic recombination (ensures haploid is genetically distinct)

What large cell formation is created during the saccharomyces reproduction cycle?

Ascus (diploid), a bunch of cells clumped together

What is the reproduction cycle of saccharomyces?

begin in diploid phase, come together to make ascus, create haploid cells from ascus, haploid cells can combine to form new diploid cells

What is one other way saccharomyces can reproduce?

budding genetically identical cells from itself

What state (haploid or diploid) is chlamydomonas usually exist in?

haploid

when does it become diploid?

only during stressful environmental conditions

what does it create when becoming diploid?

a diploid spore

why does chlamydomonas need to become diploid during stressful conditions?

to create genetic diversity among the cells of the colony to help survive the stressful conditions

what is the reproduction cycle of chlamydomonas?

cells are normally haploid, stressful conditions become apparent, cells merge with eachother to create diploid spores, share genetic information, split up and become haploid with new genetic information, normal conditions

What state are dictyostelium usually in?

haploid

what are the three cycles of existence for dictyostelium?

sexual cycle, vegetative cycle, and social cycle

what is the purpose of each cycle

vegetative cycle exists for normal environments, the sexual cycle exists to create more cells under normal conditions, and the social cycle exists to create more genetic variable cells under stressful conditions

what happens in the vegetative cycle?

the cells exist and divide normally

what happens in the sexual cycle?

the cells begin to fuse and engulfe other cells of its species creating a macrocyst (diploid). This macrocyst then undergoes meiosis and releases normal haploid cells with new genetic information.

what happens in the social cycle?

The cells aggregate to form a multicellular "slug", this then differentiates into a fruiting body, which releases spores that germinate into new haploid cells

Explain the endosymbiotic theory

Eukaryotic organisms were created when an archaea engulfed a bacteria, becoming dependent on eachother (mitochondria and/or chloroplasts)

how long ago did the first eukaryote come to be?

2.1-1.6 billion years ago

what are four pieces of evidence for the endosymbiont theory?

double membranes (host + bacterium), cell division with FtsZ, has own DNA and rRNA, has circular chromosome

what is one exception to this theory?

amitochondriates (have no mitochondria)

what is one example of an amitochondriate?

giardia

True or False, modern experimentation has been able to provide evidence towards the endosymbiont theory?

True

One example of a eukaryotic organism that uses "endosymbiosis" in its life?

Paramecium engulfing algae to provide energy, then digesting them at night

what classification of eukaryotes cause many eukaryal diseases?

protozoa

What is less likely to cause disease, but can do so in immuno-compromised individuals?

fungi

What eukaryotic organism (fungi) causes potato blight?

Phytopthora Infestans

What eukaryotic organism (fungi) causes black spots on tree leaves?

rhytisma

What Eukaryotic organism (fungi) causes insects (such as worms) to die?

cordyceps