TLS Online TPP Program

#Question id: 422


The flow of material through a reaction pathway usually depends on ________.

#Unit 1. Molecules and their Interaction Relevant to Biology
  1. control at several steps in the pathway

  2. control of the first step of the pathway

  3. covalent modification of the enzyme that catalyzes the reaction

  4. feed-forward activation

More Questions
TLS Online TPP Program

#Question id: 13198

#Unit 6. System Physiology – Plant

The sugar is a carbohydrate that are generally translocated  in the phloem in which form?

TLS Online TPP Program

#Question id: 13199

#Unit 6. System Physiology – Plant

The non-reducing sugar sucrose is most commonly translocated in the phloem rather than reducing sugar. Why?
a.) because they are less reactive than their reducing counterparts
b.) because sucrose contains more energy than a monosaccharides
c.) because the ketone or aldehyde group is reduced to an alcohol or combined with a similar group on another sugar so as not to be oxidized 
Which one of the following statements is true about translocation of non-reducing sugar?

TLS Online TPP Program

#Question id: 13200

#Unit 6. System Physiology – Plant

In the modification of translocation pathways, Interference with a translocation pathway by wounding or pruning can alter the patterns established by proximity and vascular connections. In the absence of direct connections between source and sink, vascular interconnections, called

TLS Online TPP Program

#Question id: 13201

#Unit 6. System Physiology – Plant

Phloem loading in the apoplastic pathway thought to mediate the transport of sucrose from the apoplast into the sieve element– companion cell complex. Which of the following  are involved in such sucrose transporting by apoplast?
a) Sucrose is at a higher concentration in the sieve element–companion cell complex indicates that sucrose is actively transported against its chemical-potential gradient
b) Sugars transport from the apoplast into the sieve elements and companion cells energy driven process
c) Phloem loading in the apoplastic pathway involves a sucrose–H+ symporter
d) the route of phloem loading is−mesophyll cells→ bundle sheath cells→ phloem parenchyma cell→ ordinary companion cell→ sieve elements
Which of the following is incorrect?

TLS Online TPP Program

#Question id: 13202

#Unit 6. System Physiology – Plant

Which of the following sucrose-H+ symporter appear to be the major sucrose transporters in phloem loading into the companion cells;

TLS Online TPP Program

#Question id: 13203

#Unit 6. System Physiology – Plant

Intermediary cells are specialized companion cells that are involved in phloem loading in the plant. Which of the following pathway that have included the intermediary-type companion cells?