Ch 15.1-15.3

Question 1

biosynthesis is aka

Answer 1

anabolism

Question 2

3 things biosyn requires

Answer 2

essential nutrients transported into the cell (C, N, P, S, O, H) or metals

energy (couple ATP hydrolysis)

reducing power (NADH, NADPH)

Question 3

prototrophic

Answer 3

microorganism has the same nutritional requirements as it did when isolated in nature

ex. E. coli can make everything it needs

Question 4

auxotrophic

Answer 4

a mutant that only grows when provided a specific nutrient

Question 5

fastidious

Answer 5

a microbe that requires many more nutrients than normal

maybe due to enzyme mutation

Question 6

is biosynthetic capability related to the complexity of the microbe?

Answer 6

yes

Question 7

unity of biochemistry

Answer 7

biosyn pathways discovered in bacteria are often found in all other organisms including plants/animals

Question 8

are biosyn pathways and their enzymes physically associated in the cell?

Answer 8

yes, makes the pathways faster

ordered enzymes and pathways

Question 9

operons

Answer 9

group of genes encoding biosynthetic pathways that are all expressed at once

Question 10

biosynthetic pathways are linked to ______ _______ pathways

Answer 10

central metabolism

and the formation of precursor molecules which make families of molecules

Question 11

aa families

Answer 11

aromatics

aspartate

serine

glutamate

pyruvate

Question 12

other families

Answer 12

nucleotides

phospholipids

cell wall components

Question 13

biosynthetic pathways can be 3 things

Answer 13

single

parallel

branched or convergent

Question 14

anaplerotic rxns

Answer 14

make intermediate metabolites

ex. PEP + CO2 –> oxaloacetate

Question 15

regulation of biosyn pathways occurs in 2 ways

Answer 15

enzyme level (feedback inhibition from buildup of intermediates or end product via allosteric sites)

gene regulation (transcription/translation)

Question 16

medical uses of biosyn

Answer 16

exploit pathways by targeting enzymes or intermediates to kill pathogens

ex. mimics of essential molecules used for biosyn of peptidoglycan in mycobacterium TB drugs

Question 17

other bioproduct polydroxyalkanoates

Answer 17

a form of strong polyester made by soil bacteria and synthesized in large amounts by engineered E. coli

make biodegradable sutures

Question 18

gluconeogenesis

Answer 18

reverse glycolosis to make glucose or fructose

used when microbes are grown on 2-4C sugars

7 shared enzymes, 4 are used only for gluconeogenesis

Question 19

CO2 fixation by what cycle

Answer 19

Calvin cycle

Question 20

Calvin cycle used by what 4 groups

Answer 20

plants/algae

oxygenic phototrophs (cyanobacteria)

facultative anaerobic

lithoautotrophs

Question 21

3 steps of Calvin cycle

Answer 21

carboxylation by rubisco

reduction

regeneration of ribulose 1,5 bisP

Question 22

rubisco

Answer 22

ribulose bisphosphate carboxylase

catalyzes condensation of CO2 to ribulose 1,5 bisP and splitting of unstable 6C intermediate into two 3C PGA molecules

inefficient and slow, very abundant 3CO2/sec

Question 23

regulation of calvin cycle

Answer 23

rubisco contained in structures called carboxysomes

Question 24

carboxysomes

Answer 24

take up bicarbonate which is converted to CO2 by carbonic anhydrase

then CO2 is fixed by rubisco

Question 25

stoichiometry of calvin cycle

Answer 25

(3) 5C ribulose 1,5 bisP + 3 CO2 –> (6) 3PG
(5) 3PG are recycled to ribulose 1,5 bisP
(1) 3PG is used to make sugars

Question 26

carbon concentrating mechanism (CCM) in cyanobacteria

Answer 26

different ways CO2/HCO3- brought into cell depending on envir conditions

constitutive low affinity CO2 transporters

inducible high affinity CO2/HCO3- transporters when nutrients low

Question 27

reductive (reverse) TCA cycle

Answer 27

uses 4-5 ATP to fix (4) CO2 and make (1) oxaloacetate

reduction by NADPH or NADH or FADH2

green sulfur bacteria - chlorobium (PSII)

Question 28

reductive acetyl CoA pathway used by what 3 groups

Answer 28

acetogenic bacteria

sulfate reducers

methanogens

Question 29

reductive acetyl CoA pathway

Answer 29

(2) CO2 condensed by converging pathways to make acetyl group of acetyl CoA

carbon monoxide intermediate

reducing agent is H2

Question 30

3-hydroxypropionate cycle

Answer 30

green phototrophs that are not chlorobium

acetyl CoA + HCO3 and 2 NADPH –> 3-hydroxypropinoate

(3) CO2 fixed into 1 pyruvate used for biosynthesis

Question 31

secondary metabolites

Answer 31

made through biosynthetic pathways but arent essential for survival

can make survival easier

ex. high affinity transporters, antibiotics