Passive transport is a movement ofbiochemicals and other atomic or molecularsubstances across cell membranes without need of energy input. Unlike active transport, it does not require an input of cellular energy because it is instead driven by the tendency of the system to grow in entropy. The rate of passive transport depends on thepermeability of the cell membrane, which, in turn, depends on the organization and characteristics of the membrane lipids andproteins. The four main kinds of passive transport are simple diffusion, facilitated diffusion, filtration and osmosis.
        
             
        
        
        
Explanation:
The main activity that occurs at the transmissive segment is the release of neurotransmitter from synaptic vesicles . Prior to the arrival of the action potential, Ca2+ pumps embedded in the plasma membrane of a synaptic knob establish a calcium concentration gradient by pumping it out to the IF. Consequently, there is more calcium inside of the synaptic knob than outside it.
Further Explanation:
At synaptic junctions:
- The action potential travels along the membrane until the synapse where it’s electrical depolarization leads to the opening of channels allowing Ca2+ to rush into the terminal due to higher extracellular concentrations
- these flow through a presynaptic membrane until the concentration is built up, activating ion sensitive proteins attached to vesicles containing neurotransmitters
- this leads to changes in the proteins leading to the fusion with the membrane of the presynaptic cell, so vesicles are open and neurotransmitter is released. The neurotransmitter diffuses across to chemical receptors on the presynaptic cell where they bind temporarily
- This leads to activation of specific complexes, enabling the transmission of information. Thus, the chemical signal is transferred through this neuron as an electrical impulse
Learn more about the autonomic nervous system at brainly.com/question/10386413
Learn more about neurotransmitters at brainly.com/question/9424160
Learn more about homeostasis at brainly.com/question/1601808
#LearnWithBrainly
Read more on Brainly.com - brainly.com/question/13844620#readmore
 
        
             
        
        
        
Smooth ER<span> also regulates and releases calcium ions and processes toxins. It is described as '</span>smooth<span>' to distinguish it from rough </span>ER<span>, which has ribosomes for protein synthesis on its surface. Each organelle in the cytoplasm of a cell is responsible for performing a certain function.</span>
        
             
        
        
        
Answer:
The gene cannot be transcribed and translated into a protein.
Explanation:
Turning off a gene means the gene cannot be transcribed and translated into a protein.
Turning off of genes is a form of gene regulation, a process that controls which genes are expressed or not expressed in a cell.
<u>The expression of genes requires that they are first transcribed from DNA to mRNA in the nucleus and then moved to cytoplasm where they are translated into proteins by the ribosome.</u>
Hence, a gene that will not be expressed has to be stopped from being transcribed amd translated by being turned off by the gene regulation process of the cell.
 
        
                    
             
        
        
        
Answer: 
Hazen has provided chemical analyses, bench-scale experiments, continuous pilot plant demonstration, and field and other services. Hazen also designs flowsheets and reduces scaleup risks for commercial plants throughout the world
Explanation: