Answer:
Both facilitated diffusion and active transport are selective processes. Only selective molecules are allowed to cross the membrane. They utilize carrier proteins to move across the membrane.
Explanation:
Diffusion is the process by which molecules move across a membrane respective of the concentration gradient. The plasma membrane is a <em>selectively permeable membrane</em> which allows specific molecules to move across the concentration gradient.
Molecules migrate from a region of higher concentration to a lower concentration in case of diffusion. It can be classified into simple diffusion and facilitated diffusion. These are examples of <em>passive transport</em>.
In facilitated diffusion molecules move across the concentration gradient with the help of <em>carrier proteins or channel proteins</em>. The carrier proteins bind to the molecule which has to be transported and change conformation to allow it to cross the membrane. For example glucose molecule is carried across through <em>GLUT transporter</em>. <em>Channel proteins</em> open a channel inside the membrane and molecules get transported across the gradient.
Active transport carries molecules against the concentration gradient with the assist of energy. ATP hydrolysis is utilized to generate energy. As a result of active transport, the molecules are aggregated on one side of the membrane.
We see the moon because the sun's light reflects off it. So the phases change depending on how much the sun reflects of it. The moon circles around the Earth so at certain times there will be a full moon and at certain times a new moon and everything in between.
Answer:
A)Fixation. Nitrogen in its gaseous form (N2) can't be used by most living things
B) it can not be used because it most be converted or, ’fixed’ to a more useable form. To do this it goes through a process called fixation.fixation is the change in a gene pool from a situation where there exists at least two variants of a particular gene (allele) in a given population to a situation where only one of the alleles remains.
C) This form can be made more usable if it’s converted. It has to go through the process of fixation so the gene pool changes.
Explanation:
Enzymes can be destroyed by variations in temperature or pH
