Answer: This answer is for all the questions: Chargaff's rules state that DNA from any species of any organism should have a 1:1 stoichiometric ratio of purine and pyrimidine bases (i.e., A+G=T+C) and, more specifically, that the amount of guanine should be equal to cytosine and the amount of adenine should be equal to thymine.
Explanation:
Answer:
Vesicles
Explanation:
Serotonin is a neurotransmitter that transports signals or messages between neurons.
Most neuronal cells have vesicles in their interior, which are organelles that store neurotransmitters for exportation -by exocytosis- or from recycling -by endocytosis-. These vesicles also protect the neurotransmitter from the enzymatic action.
Vesicles form in the cellular soma, from where they are transported to nervous terminals. Once the vesicle releases the neurotransmitter to the intercellular space, their membrane remains available in the plasmatic membrane to be reused.
The neurotransmitter concentration in the vesicle interior is related to the storage system and the <u>transport system</u>. There are <u>specialized transporter proteins in the vesicle membrane</u> that are involved with the introduction of the molecule to the organelle.
In the exposed example, transporter Trans B might be located in the vesicle membranes, and hence could be found in the cytosol of the cells.
Answer:
The voltage-gated potassium channels associated with an action potential provide an example of what type of membrane transport?
A. Simple diffusion.
B.<u> Facilitated diffusion.
</u>
C. Coupled transport.
D. Active transport.
You are studying the entry of a small molecule into red blood cells. You determine the rate of movement across the membrane under a variety of conditions and make the following observations:
i. The molecules can move across the membrane in either direction.
ii. The molecules always move down their concentration gradient.
iii. No energy source is required for the molecules to move across the membrane.
iv. As the difference in concentration across the membrane increases, the rate of transport reaches a maximum.
The mechanism used to get this molecule across the membrane is most likely:
A. simple diffusion.
<u>B. facilitated diffusion.
</u>
C. active transport.
D. There is not enough information to determine a mechanism.
Carrier proteins - exist in two conformations, altered by high affinity binding of the transported molecule. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLE: GluT1 erythrocyte glucose transporter.
Channel proteins - primarily for ion transport. Form an aqueous pore through the lipid bilayer. May be gated. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLES: Voltage-gated sodium channel, erytrhocyte bicarbonate exchange protein.
This might be helpful... because I don't know anything about facilitated diffusion.
<h2>
Liver cell Vs Nerve cell</h2>
Explanation:
- b. liver cells can reproduce while the nerve cells cannot.
Liver cells , the fundamental units of liver are called hepatocytes. Hepatocytes secrete bile that helps in digestion by emulsifying fats. Hepatocytes are capable of dividing and they can regenerate damaged parts of the liver.
In contrast,
Nerve cells, the fundamental unit of nervous system are neurons. Neurons are longest cell of the human body and they contain a cell body and a long axon. Neurons conduct nerve impulses. Neurons are incapable of dividing and hence once damaged neuron cannot be replaced.
Pathogens can exist in blood and then can be passed the transfusions
