Bio 311 Test Questions and Answers | Latest
Update | 100% Correct.
enzymes
increase the rate of a reaction WITHOUT affecting the reaction equilibrium
covalent vs noncovalent interactions in an macromolecule
non-covalent; weak
h-bonding, Van der Waals, hydrophobic effect, electrostatic (ionic attraction), hydrophobic effect
stabilizes the macromolecule, transport, substrate binding, folding
covalent bonds- disulfide bonds, peptide bonds
metabolism- catabolism vs anabolism
catabolism- break down macromolecules, release of energy
(-ΔG'° standard free energy) favorable
creates ATP (-30 kJ/mol), NADH, NADPH, FADH2- oxidative. the removal of electrons
releases energy
anabolism- synthetic, makes molecules, absorbs energy, reductive, unfavorable (+ΔG'°) often
coupled to an exergonic reaction
uses energy
,autotrophs vs heterotrophs
use carbon from the air CO2 energy from the sun to make O2 and H2O
phototrophs- use CO2 but also sunlight, the energy source is
heterotrophs- use carbon from food energy, makes CO2 and H2O
nitrogen cycle in biosphere
atmosphere N2 gas -> nitrogen fixing bacteria -> ammonia NH3+ (reduced)
then fed into the loop of nitrogen cycle, nitrifying bacteria, nitrates, plants, amino acids, animals
nonlinear metabolic pathways
converging, catabolic
diverging anabolic, and cyclic (regeneration of key intermediates)
acetyl Co-A very important intermediate
FAD/FADH and FMN/FMNH act as coenzymes in enzyme catalyzed redox reactions
dehydrogenases are enzymes that carry out redox reactions
oxidation states of carbon biomolecules
carbon dioxide most oxidized
carbox acid
aldehyde
, alcohol
alkane
example- oxidation of lactate to pyruvate by lactate dehydrogenase
lactate has an OH group and pyruvate has an C=O group REVERSIBLE
mechanisms for cleav of C-C or C-H bond (carbocation/anion)
homolytic cleav- BOTH atoms retain bonding electrons) creates a carbon radical and H atom ->
carbon radicals
methylmalonyl CoA mutase in addition of coenzyme B12- homolytic cleav to create free
radicals.
the swap of MMCoA and H on the 2 and 3 carbon- hydrogen swapping because of coenzyme
b12 that has cobalt in it and cleaves the triphosphate group of ATP on the 5' carbon of the ribose.
H trapping effective because the generation of carbon radical intermediates- very unstable trying
to reach stability. starts with deoxyadenosyl free radical, substrate add in then substrate radical,
finally product like radical, product.
heterolytic cleav- ONLY ONE OF 2 bonding atoms retains bonding electrons) carbanion and
proton or carbocation and hydride (H-) produces carbocation and carbanion
isomerization
Update | 100% Correct.
enzymes
increase the rate of a reaction WITHOUT affecting the reaction equilibrium
covalent vs noncovalent interactions in an macromolecule
non-covalent; weak
h-bonding, Van der Waals, hydrophobic effect, electrostatic (ionic attraction), hydrophobic effect
stabilizes the macromolecule, transport, substrate binding, folding
covalent bonds- disulfide bonds, peptide bonds
metabolism- catabolism vs anabolism
catabolism- break down macromolecules, release of energy
(-ΔG'° standard free energy) favorable
creates ATP (-30 kJ/mol), NADH, NADPH, FADH2- oxidative. the removal of electrons
releases energy
anabolism- synthetic, makes molecules, absorbs energy, reductive, unfavorable (+ΔG'°) often
coupled to an exergonic reaction
uses energy
,autotrophs vs heterotrophs
use carbon from the air CO2 energy from the sun to make O2 and H2O
phototrophs- use CO2 but also sunlight, the energy source is
heterotrophs- use carbon from food energy, makes CO2 and H2O
nitrogen cycle in biosphere
atmosphere N2 gas -> nitrogen fixing bacteria -> ammonia NH3+ (reduced)
then fed into the loop of nitrogen cycle, nitrifying bacteria, nitrates, plants, amino acids, animals
nonlinear metabolic pathways
converging, catabolic
diverging anabolic, and cyclic (regeneration of key intermediates)
acetyl Co-A very important intermediate
FAD/FADH and FMN/FMNH act as coenzymes in enzyme catalyzed redox reactions
dehydrogenases are enzymes that carry out redox reactions
oxidation states of carbon biomolecules
carbon dioxide most oxidized
carbox acid
aldehyde
, alcohol
alkane
example- oxidation of lactate to pyruvate by lactate dehydrogenase
lactate has an OH group and pyruvate has an C=O group REVERSIBLE
mechanisms for cleav of C-C or C-H bond (carbocation/anion)
homolytic cleav- BOTH atoms retain bonding electrons) creates a carbon radical and H atom ->
carbon radicals
methylmalonyl CoA mutase in addition of coenzyme B12- homolytic cleav to create free
radicals.
the swap of MMCoA and H on the 2 and 3 carbon- hydrogen swapping because of coenzyme
b12 that has cobalt in it and cleaves the triphosphate group of ATP on the 5' carbon of the ribose.
H trapping effective because the generation of carbon radical intermediates- very unstable trying
to reach stability. starts with deoxyadenosyl free radical, substrate add in then substrate radical,
finally product like radical, product.
heterolytic cleav- ONLY ONE OF 2 bonding atoms retains bonding electrons) carbanion and
proton or carbocation and hydride (H-) produces carbocation and carbanion
isomerization
