microbiology exam 3

what is molecular oxygen used as

a terminal electron acceptor

where is the ETC located?

the mitrochondria

where was the ETC invented and where did it occur?

Prokaryotes, they stored protons in the periplasmic space

What is NADH’s role in the ETC?

it drops electrons off at the first protein pump

What does FADH2 do in the ETC?

it drops the elctrons off at the second protein pump

what is the job of the electron transport chain?

turn electron energy into proton energy

what is the proton and pH gradient of the etc?

high proton low pH to low proton high pH

What is pi from ATP?

breaking off one phosphate

what is the first enzyme in glucolysis?

hexokinase

what is another name for glycolysis?

Embden Meyerhoff (Parnas) 

what enzyme phosphorylates glucose to glucose-6-phosphate

hexokinase

phosphoglucoisomerase

converts glucose-6-phosphate to fructose-6-phosphate

phosphofructokinase

converts fructose-6-phosphate to fructose-1,6-bisphosphate

what does fructose 1,6 bisphosphate become in glycolysis?

DHAP and G3P

Converts DHAP to G3P

triosephosphateisomerase

triophosphatedehydrogenase 

converts G3P to 1,3-bisphosphoglycerate

phosphoglycerokinase

converts 1,3-bisphosphoglycerate to 3-phosphoglycerate

phosphoglyceromutase

converts 3-phosphoglycerate to 2-phosphoglycerate

enolase

converts 2-phosphoglycerate to PEP

pyruvatekinase

converts PEP to pyruvate

what do the short circuited steps of glycolysis need?

ATP

what compound is used in gluconeogenesis and TCA cycle?

Oxloacetate

What is the order of intermediates in the TCA cycle?

Citrate, Isocitrate, a-Ketoglutarate, Succinyl-CoA, Succinate, Fumarate, Malate, Oxaloacetate

What are the products of glycolysis?

2 pyruvate, 2 ATP, 2 NADH

What is the product of gluconeogenesis

Glucose

What are the products of Enter douderoff (ED)

KDPG, 1 ATP, 1 NADH, 1 NADPH, 2 Pyruvate

What are the products of the oxidative pentose phosphate pathway (PPP)

2 NADPH, Ru5P, 1 CO2

What are the products of the non-oxidative PPP

3-7C sugars

What are the products of the pyruvate oxidation pathway?

1 NADH, 1 CO2, 1 acetyl Co-A

What are the products of the TCA cycle?

3 NADH, 1 FADH2, 1 CO2, 1 ATP/GTP

What three steps of the TCA cycle use NAD to make NADH?

Isocitrate to a-Ketoglutarate

a- ketoglutarate to succinyl Co-A

Malate to oxloacetate

What step of the TCA cycle uses ADP (or GDP)

Succinyl Co-A to Succinate

What step of the TCA cycle uses FADH2 to FAD

Succinate to fumarate

What are the 4 gluconeogenic enzymes?

Pyruvate carboxylase

PEP Carbokinase

Fructose 1,6-bisphophatase

Glucose 6 phosphatase

Pyruvate Carboxylase

pyrucate to oxloaceate

PEP Carbokinase

Oxaloacetate to PEP

Fructose 1,6 bisphosphatase

F-1,6 BP to Fructose 6 phosphate

Glucose 6 phosphatase

G6P to glucose

Non-reversible PPP

oixidative

Reversible PPP

non-Oxidative

What is the purpose of fermentation

to keep ATP production going ig there is not the proper elements available for glycolysis

does fermentation produce more ATP than glycolysis?

No

how is NAD+ used in fermentation

it gets converted to NADH

homolactic fermentation 

converts 2 pyruvate into 2 lactic acid

heterolactic fermentation

1 pyruvate - 1 lactic acid

1 pyruvate - CO2 + Ethanol

what types of tests can be used to identify organisms that do fermentation

phenol red broth tests, other acid detection

What are the 4 unifying themes of fermentation

1. O2 not needed

2. e- acceptor is pyruvate/ derivative

3. NADH is oxidized to NAD

4. no ETC so not a good ATP source

what does the VP test for ?

butylene glycol pathway

when reduced, NAD accepts

1 proton and 2 electrons

catasbolic pathways are used by organisms to

break down molecules and release energy

What type of bond does ATP break down 

Phosphodiester 

The assembly of DNA is energized by

ATP hydrolysis and the release of pyrophosphate

what does Pyruvate oxidation not produce?

ATP

Which step in TCA produces NADH but not CO2?

Malate-->oxaloacetate

what enzyme can be shut down to preserve oxygen?

pyruvatedehydrogenase

where does the TCA cycle happen in prokaryotes?

the cytoplasm

where does the TCA cycle happen in Eukaryotes

the mitochondrial matrix

What can cells use if glucose is absent

the glyoxylate shunt/ bypass to catabolize fatty acids. Skips over a-ketoglutarate and turns iscitrate to glyoxylate

what does the glyoxylate bypass produce?

2 NADH, 1FADH2

can animal cells do anaerobic respiration?

no they do fermentation

Because fermentation produces less ATP than respiration, how do microbes compensate? 

they consume more glucose to produce more ATP

what does pyruvate hydrogenase not produce?

ATP

what two products are not produced in the glyoxylate bypass?

a-ketoglutarate, Succinyl Co-A

How are prokaryotic ETC different from ours?

produce less ATP, branched, different TEAs, different e carriers

How is the PMF used?

drive flagella, provide ATP, active transport

F1 ATP synthase molecule

protrudes into the cytoplasm and generates ATP

F0 ATP synthase molecule

embedded in the membrane and pumps protons

What is the Paracoccus Denitrificans anaerobic respiration process set up?

Nitrate- nitrite- NO - N2O- N2

dissimilatory nitrate reduction

use of nitrate as a terminal electron acceptor that makes it unavailable for the cell for uptake/assimilation. Not always bad.

Denitrification

reduction of Nitrate to N2 gas, causes loss of soil fertility

chemolithotrophy

chemicals as energy and inorganic sources as electron acceptors

what are the three major groups of chemolithotrophs?

hydrogen oxidizers

Nitrifying bacteria

Sulfur-oxidizer

phototrophy

light dependent reactions that use photons to excite electrons and generate PMF

what is the main goat of phototrophy?

to turn a proton gradient into a PMF

is phototrophy the same thing as photosthesis?

No

what color would rhodpsin based phototrophs appear?

purple because they absorb green light and reflect purple/red/blue

rhodopsin based phototrphy

one of the simplest forms, involves a retinal molecule and a one membered protein that functions as a proton pump

antenna complexes

organized light harvesting (LH) arrays of chlorophyll and accessory pigments. like the dish of a satellite

Reaction center complex

photosytem I and II. Where light energy is absorbed by LH complexes and photon energy is separated from the chlorophyll.

Photoexitation

Light absorptions raises e- to higher state

photoionization

light absorption causes e- separation

Photolysis

light absorption splits a molecule (like H2O)

Photosynthesis

Photolysis with CO2 fixation and biosynthesis

non-cyclic photosynthesis

makes O2 + ATP + NADPH

Cyclic photosynthesis

only generates ATP

cyanobacteria

oxygen producing bacteria that contain chlorophyll

where did cyanobacteria originate from?

took advantage of a purple earth, eating the light that rhodopsin bacteria reflected

purple sulfer bacteria

splits H2S to acquire electrons

how does cyanobacteria gain electrons for ATP synthesis?

photoexitation splits H2O and releases e-

how much of the earth’s oxygen does cyanobacteria generate? plants? algae?

1/4, 1/2, 1/4

chromophore

light absorbing e- carrier

rhodobacter

purple sulfur bacteria that absorb light missed by cyanobacteria

Carbon fixation in the Calvin cycle

Rubisco fixes CO2 to Ru-15BP

Carbon reduction in the calvin cycle

6 ATP and NADPH convert 3-PGA to G3P

regeneration calvin cycle

G3P regenerates Ru1,5BP using 3 ATP

what organisms do oxygeneic phototrophy?

cyanobacteria and eukaryotes like algae

Rhodopsin-based phototrophs differ from other phototrophs in that they lack:

an ETC

The chromophore of chlorophyll contains an atom of

Mg

The Calvin Benson Bassham Cycle produces which carbohydrates?

RuBP and G3P