Chapter 2: Microbial Metabolism Flashcards
metabolism
sum of all chemical reactions in an organism
catabolism
provides energy and building blocks for anabolism
polymers to monomers
anabolism (lysis)
uses energy and building blocks to build large molecules (synthesis)
monomers to polymers
metabolic pathway
sequence of enzymatically catalyzed chemical reactions in a cell
metabolic pathway sequence prevents
overproduction
equation for ATP
ADP + P(i)= ATP
collision theory
chemical reactions occur when atoms collide
activation energy
minimum energy needed to disrupt electronic configuration and allow reaction to occur
what do enzymes do to activation energy
decrease it, thus increasing reaction rate
reaction rate
frequency of collisions with enough energy for a reaction
reaction rate can be increased by
enzyme, increase in temp or pressure
enzymes
biological catalysts, protein, specific to a certain substance, not used in a reaction
components of enzymes
apoenzymes, cofactor, holoenzymes
apoenzymes
inactive enzymes
holoenzymes
active enzymes
coenzymes
NAD+ (vitamin B-12), NADP+, FAD
how can enzymes be denatured
temperature or pH
what influences enzyme activity
substrate concentration
competitive inhibitors
inhibitor fits into active site and directly blocks substrate from binding
noncompetitive inhibitors
inhibitor fits into allosteric site - changes shape of active site indirectly preventing substrate from binding
feedback inhibition
controls amount of substrate produced by a cell, usually allosteric inhibition
final product serves as noncompetitive inhibitor
confirmational change
changing shape of protein
redox reaciton
oxidation, reduction
LEO says GER
biological oxidations are often
dehydrogenations
ATP
adenosine triphosphate
adenosine
adenine and ribose
phosphorylation
adding phosphate to ADP to make ATP
substrate level phosphorylation
transfer of high energy PO4- to ADP (free floating enzyme in cytosol)
oxidative phosphorylation
transfer of electrons from one compound to another to generate ATP by chemiosmosis
photosynthesis reduction equation
H2O + CO2 -> C6H12O6 + O2 + H2O
chemosynthesis equation
H2S + CO2 -> C6H12O6 + S
3 steps of aerobic respiration
glycolysis
kreb’s cycle
oxidative phosphorylation
glycolysis
multistep breakdown of glucose into pyruvate generates net 2 ATP and 2 NADH
glycolysis occurs where
cytoplasm
glycolysis is oldest pathway because
doesn’t need O2
every lifeform uses it
occurs in cytoplasm
alternate pathways
pentose phosphate and entner-doudoroff
pentose phosphate
yields net gains of only 1 ATP for each glucose
entner-doudoroff
yields 2 NADPH and 1 ATP
kreb’s cycle
oxidation of acetyl CoA
kreb’s cycle occurs in
mitochondrial matrix
transition step generates
acetyl CoA from pyruvate (decomposition)
krebs cycle produces
2 ATP and 3 NADH and precursor metabolites
electron transport chain occurs in
cristae of mitochondria
ETC formed by
series of cytochromes (electron carriers)
redox reactions in ETC
electron carriers from glycolysis and krebs cycle transfer their electrons to ETC
pmf
proton motive force
in chemiosmosis, pmf generates
energy via oxidative phosphorylation
main purpose of krebs cycle is to
harvest hydrogen to be used in ETC
three ways of disrupting ATP synthesis
block cytochrome
knock out ATPase
make phosphobilipid layer leaky
final electron acceptor in anaerobic respiration
inorganic molecule NO3-, SO4-2
practical uses of fermentation
spoilage of food, alcohol or acidic dairy production, industrial processes
amylase
digests carbohydrates
cellulase
digests cellulose (only bacteria and fungi have this enzyme)
protein digested by
extracellular proteases into amino acids
how to break down amino acids into organic acids
deamination
decarboxylation
dehydrogenation
desulfurylation
chemoheterotroph
use same organic compound as energy source and carbon source