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The passage of hydrogen cations from the intermembrane space through the inner minochondrial to the mitochondrial matrix without the participation of the ATP synthase complex is: (select one)
a. reduction
b. oxidation
c. linking electronic transport to phosphorylation
d. uncoupling electronic transport and phosphorylation
e. active transport
The completion (termination) of the transcription shall be performed when: (select one or more)
a. RNA polymerase reaches the end of the chromosome
b. specific sequences at the 5 'end of the transcript determine the termination
c. the sigma subunit dissociates from RNA polymerase
d. a structural motif is formed that favors the dissociation of the polymerase
e. a protein binds to DNA that intercalates between bases and blocks transcription
A monomeric enzyme catalyzing a reaction located somewhere in the middle of a metabolic pathway has mutated so that the value of Km for its only substrate has doubled. Under constant other conditions, how should the concentration of the substrate of this enzyme be changed so that the rate of metabolic flow through this metabolic chain remains constant? (select one)
a. to reduce it three times
b. to reduce it exactly in half
c. to increase it exactly twice
d. to increase it between one and a half times
e. to increase it more than double
Identify plant tissues found in roots,stems and leaves. What will happen if these tissues are damaged due to loss of soil nutrients, water and pests.
Which is the first regulated glycolytic metabolic enzyme that directs glucose only to degradation? (select one)
a. aldolase
b. glyceraldehyde-3-phosphate dehydrogenase
c. phosphofructokinase
d. lactate dehydrogenase
e. hexokinase
Which of the following reactions is a source of significant amounts of glycerol-3-phosphate required for lipid biosynthesis (select one or more)
a. reductive phosphorylation of pyruvate
b. phosphorylation of glycerol
c. reduction of dihydroxyacetone phosphate
d. dephosphorylation of 1,3-bisphosphoglycerate
e. oxidation of glyceraldehyde-3-phosphate
Which of the reactions catalyzed by the listed enzymes does not produce ammonia?
a. glutamate pyruvate amino transferase
b. glutamate decarboxylase
c. glutamine hydrolase
d. aspartate deaminase
e. glutamate dehydrogenase
At pH 2, most proteins lose biological activity. Why? (select one or more)
a. the distribution of salt bridges changes
b. denaturation occurs due to unfolding of the polypeptide chain
c. the side chains are protonated and the charge of the protein changes
d. decompose
The enzyme fumarase catalyzes the reversible hydration of fumarate to L-malate, but not the hydration of maleic acid (cis-isomer) of fumarate. This is an example of (select one)
a. chiral activity
b. stereoisomerism
c. biological activity
d. stereospecificity
e. racemization
Cite at least 2 specialized roots and leaves then identify it's economic importance to humans.
