Transport proteins (carrier proteins and channel proteins) allow substances into and out of the cell that cannot pass through the phospholipid bilayer (as they’re either to large, charged or not lipid soluble) by facilitated diffusion.
Specifically channel proteins allow ions into and out of the cell by creating a pore in the membrane in which they can move through with their concentration gradient
Answer:
D) Frequency results from environmental stresses, not dominance.
Explanation:
The allele frequency refers to the amount of frequency of a particular allele in a small population whereas the dominance and recessive are the measure of the effects of the allele on the population which decides the trait of an organism.
The frequency and dominance cannot be correlated with each other as the frequency of the allele in a population is the result of the environmental stress which are random and by chances, whereas the effect of dominance is not random but is the result of the favoured trait for survival.
Thus, Option-D is correct.
I would say that active transport is the answer because it's from LOW concentration to HIGH concentrations, so it's going against the concentration gradients.
Answer:
The exergonic reaction of hydrolysis of ATP must be coupled to an endergonic reaction to perform work or to power other reactions.
Explanation:
ATP (adenosin triphosphate) is hydrolized to give ADP and releases energy as follows:
ATP + H₂O ⇆ ADP + Pi + energy
The released energy itself is not used to power biochemical reaction. In order to power other reactions, ATP hydrolysis- a energetically favorable reaction- is coupled to another energetically disfavorable reaction. The linking or coupling is performed through a shared intermediate, which is often a phosphorilated molecule. For example, in the formation reaction of sucrose from glucose and fructose, an intermediate is formated by the transfer of a phosphate group (Pi) provided by ATP hydrolysis. Then, the phosphorilated intermediate (glucose-Pi)- wich is unstable- reacts with fructose in a spontaneous reaction to give sucrose.
