D. An element donates an electron to another element.
The correct answer is: b. It is free to bind to another promoter and begin transcription
Transcription is the first step of gene expression in which DNA molecule is copied (transcribed) into RNA (mRNA) by RNA polymerase. The process of transcription is divided into three phases:
1. Initiation
• RNA polymerase with transcriptional factors bind to gene promoter
• RNA polymerase unwinds DNA double helix (transcription bubble is formed)
2. Elongation
• RNA polymerases adds nucleotides complementary to DNA
3. Termination
• RNA polymerase gets to stop codon (transcribes a sequence of DNA known as a terminator)
• Formed complementary RNA strand is released from DNA-RNA complex.
RNA polymerase is also released and can transcribe some other gene by binding to its promotor. RNA polymerase will transcribe just the genes whose products are needed at a particular moment.
they must be unicellular and microscopic and they must be eukaryotic
Glutamine and glutamate are the primary nitrogen donors for biosynthetic reactions in the cell. Glutamine is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, polar amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet. Glutamate is generally acknowledged to be the most important transmitter for normal brain function. Nearly all excitatory neurons in the central nervous system<span> are glutamatergic, and it is estimated that over half of all brain synapses release this agent. Glutamate plays an especially important role in clinical neurology because elevated concentrations of extracellular glutamate, released as a result of neural injury, are toxic to neurons</span>
Nuclear power plants use the nuclear fission reaction to release energy and generate electricity through energy conversion. Take the pressurized water reactor nuclear power plant as an example to illustrate its working principle.
In the pressurized water reactor, a large amount of heat is generated by the self-sustaining chain fission reaction of the nuclear fuel nucleus. The coolant (also called the heat carrier) brings the heat in the reactor to the steam generator and transfers the heat to the working medium, water. The main circulation pump then delivers the coolant back to the reactor for recycling, thereby forming a circuit called the first circuit. This process is also the energy conversion process of nuclear fission energy converted into thermal energy.
The working medium on the secondary side of the U-tube outside the steam generator is vaporized by heat to form steam. The steam enters the steam turbine to expand work, and converts the heat energy released by the steam enthalpy into the mechanical energy of the rotor of the steam turbine. This process is called thermal energy conversion to mechanical energy. The energy conversion process. The steam that has done work is condensed into condensed water in the condenser and returned to the steam generator to form another circulation loop called the second loop. This process is called the energy conversion process of converting thermal energy into mechanical energy. The rotating rotor of the steam turbine directly drives the rotor of the generator to rotate, so that the generator emits electric energy, which is an energy conversion process that converts mechanical energy into electrical energy.
