micro exam 3- cytokineses in microbes (oct 23 lecture)

what do cytoskeletal systems provide

structural support

trafficking

cytokineses

DNA replication

cell shape

what do bacteria use in the cytoskeleton

Fts Z (tubulin like proteins)

what do euk have in cytoskeleton

microfilaments (actin)

microtubules (tubulin)

intermediate filaments (vimetin, lamin)

what is the only form of cytokineses in bacteria

binary fission

what organisms can use binary fission

protists

archea

bacteria

phases of binary fission

1. B

2. C

3. D

is binary fission present in vertebrates/ multicellular organisms

no

what euk microbes can use binary fission

protists

microalgae

is the process of binary fission conserved across domains

yes

period B

time between cytokineses and initiation of chromosome replication

what does the B period determine

generation time in a cell

period C

chromosome replication and vegetation (inc in cellular volume)

what is vegetation

an increase in cellular volume

what is the length of period C determined by

by generation time

what is generation time dictated by

growth restraints

period D

cytokinesis- chromosome and cellular materials segregate and the cells divide

what is the only tubulin like protein in bacteria

Fts Z

what is binary fission initiated by

by FtsZ Z ring (polymer of FtsZ) formation at mid cell

divisome proteins

makes cell walls at the mid-cell (division scaffold)

what is septation

the separating of two cells (cleavage furrow in euk) by constricting the cell envelope, makes two genetically identical daughter cells.

archea tubulin like proteins

CetZ

FtsZ

role of CetZ

in cell shape and motility, only in archea

is FtsZ or CetZ involved in cytokineses

only ftsZ

contractile ring, what is it made of

eukaryotic homolog of a Z ring. made of F actin and myosin II. 

abiotic parameters in which most microbes live in

temp: 20C-40C

pH: 6.5-7.5

salt: 0.5%-0.9%

pressure: 1atm - sea level

water activity (A_w): 0.91- 1.0

what is water activity

the amount of water available in a cell or system

how do microbes adapt to harsh environments

• cellular differentiation (biofilms and sporulation- spores resilient to abiotic stressors)

• extremophilism

where are extremophiles (what domains)

all domains- most common in archea

extremophiles

grow and survive in extreme environments

extremotolerant

survive but do not grow

what are piezophiles (barro)

pressure sensitive

order of piezo extremophiles

piezosensitive → piezophiles → hyperpiezophiles

until what pressures can piezophiles grow

1,000 atm (100 Mpa)

what is 1 atm 

15 psi

what is 1,000 atm in psi

14,500 psi

hyperpiezophile that requires high pressure to grow

shewanella benthica (bacteria)

psi range of shewella benthica

7000 PSI to grow

Kmax is at 11,000 PSI (80Mpa)

where was shewenalla bethica found

37,000 ft under the ocean surface

how do piezophiles surivive

>90% of benthica membrane fats are unsaturated docosahexanoic acid (DHA)

what does DHA do

increases membrane fluidity under extreme pressure

what does pressure normally do to membranes and how is this combated

it normally turns membranes into solid structures. piezophiles turn all membrane into DHA- which makes the membrane fluid and allows for survival.

what is present in cold loving psychrophiles that allows for surivival

DHA in the membranes

what is the Kmax of psychrophiles plus temp range

less than 10C (-5 to 20C)

mesophiles make up what percent of microbes that are thermally classified and their temp range

more than 90% (15 to 45 C)

thermophiles temp range

40 to 80C

what is the kmax of hyperthermophiles and temp range

more than 90 C (65 to 105C)

what microbe is used to manufacture DHA as an omega fat

crypthecodinium cohnii

when does c.cohnii concentrate DHA

when grown at low temperatures

what is crypthecodinium cohnii

a dinoflagellate. also a psychrophile that produces DHA when grown at low temperatures. (dinoflagellates also responsible for red tide)

what does thermococcus kodakarensis use in extreme environments

changes in protein biochemistry

where was thermococcus kodakarensis found

in a solfatara (volcano)

thermococcus kodakarensis growth time at what temp

less than 60 min at 85 C (also polyploidic)

what does changing the amino acid primary structure of proteins do

its an adaptation that effect structural flexibility

flexibility effect in heat

reduced (membrane wants to be too fluid, to combat this, it is made more rigid)

flexiblity effect in cold

increased (membrane turns more rigid, so DHA combats this by making it flexible)

what do thermophilic proteins have compared to mesophilic proteins

• more ion pairs and bonding

• compact core containing disulfide bonds/bridges

• More H bonds

• more rigid

• more intra and intermolecular binding

thermococcus aquaticus

thermophilic

from yellowstone

contains taq (thermostable dna poly III)

what is taq useful for

in PCR because it can polymerize dna at high temps (which is needed to seperate the strands)

what did previous PCR rely on

Klenow DNA pol I of E.coli (thermo-sensitive and would break down at high temps- no dna polymerization)

what can adaptations of microbes be used for

for biotechnology

what percent of microbes can replicate in under 10 mins

10%

what is the slowest growing organism on earth

microorganism

how much could a single microbe multiply in 24 hours

10¹²

how long for a microbe to cover the surface of the earth

5 days

how long for microbe to get to 4000 times the mass of earth

5 days plus 72 hrs (8 days)

how long for fly to replicate

1 day

how long for rat to replicate

30 days

how long for whale to replicate

1 yr

size hypothesis

in macroorganisms, gestation or replication is correlated to size

size hypothesis in microorganisms

explains some part of the constraint but it is more complicated than just size

microbes and food

microbe growth is limited by the availability of nutrients and the type of nutrient because they cannot store it

what is good food

glucose and gluc-malt

what is bad food

maltose

what is maltose

a disaccharide of glucose, which requires maltase for its breakdown.

what are macronutrients used for (the big 6)

to get energy and make biopolymers

big 6 molecules

C

N

Ph

H

O

S

metal macronutrients

Magnesium (mg 2+)

Iron (Fe 2+)

Potassium (K+)

Calcium (Ca 2+)

CIMP (like simp)

what do the metal macronutrients do

make enzyme cofactors and regulatory molecules (cellular function)

what do the big 6 molecules make in order to generate energy and biosynthesis

macromolecules

micronutrients

Cobalt (Co 2+)

Copper (Cu+)

Manganese (Mn 2+)

Molybdenum (Mo 2+)

Nickel (Ni 2+)

Zinc (Zn 2+)

what do micronutrients make

make components of cofactors or enzymes

most limiting nutrient

carbon

how much of biomass does carbon control

50%

what properties of carbon make it important

tetravalency and catenation

what are the two ways carbon is assimilated 

heterotrophy and autotrophy

heterotrophy

acquire carbon from consuming other organisms

heterotrophic diagram

• carbohydrates go to the TCA by glycolysis

• fats, proteins, nucleic acids go to TCA

• this process allows for assimilation and energy

heterotrophy examples

predation

culture

disease

autotroph diagram and what is it

Gets their carbon from CO2

autotrophy examples

photosynthesis and CO2 fixation

autotrophy organisms examples

nostoc spp. (bacteria), look like rods

volvox spp. (eukarya algae), look like balls with clusters of chlorophyll

both have chlorophyll

what does growth require 

energy

phototrophic

energy obtained through chemical reactions driven by light absorption

chemotrophic

energy obtained through the rearangement of organic compounds (redox, making/breaking bonds)

decision tree of what type of organism it is

two ways energy can be used

for work or stored

types of work

transport, biosynthesis, motility, metabolism

how can energy be stored

in high energy molecules or membrane potentials (electrochemical gradients)

high energy molecules

ATP

GTP

NADH

NADPH

FADH2

PEP

broken down to access the energy

how is energy accessed from the two forms of storage

their state is changed