anything of x is base pairs, which can be shown by agct
<span>Protein tertiary structures
are known to be a three dimensional structure of a protein with a single
polypeptide chain (backbone) and one or more protein secondary structures known as
protein domains.</span>
Tertiary Structure Interactions
1) Hydrophobic Interactions: they are non-
covalent bonds and very important in the formation of tertiary structure.
2) Ionic Bonds: the interaction of both positive
and negative amino acids forms a bond that helps to stabilize the protein molecules.
3) Hydrogen Bonds: this bond exit between the
amino acid with hydrophilic side chain found on the surface of the molecules and
water molecules in a solution.
4) Disulfide Bridges: it is a strong covalent bond commonly found between cysteine residues in close proximity space.
Complete Question:
Cortisol is a hormone produced in response to stress, including starvation, in humans. Which of the following is most likely an immediate effect of a starvation-induced increase in cortisol secretion?
(A) Increased activation of the immune system
(B) Increased urine production by the kidneys
(C) Increased bone and collagen formation
(D) Increased mobilization of fatty acids from fat cells
Answer: Increased mobilization of fatty acids from fat cells.
Explanation: Cortisol is a hormone produced in response to stress, including starvation, in humans. Immediate effect of a starvation-induced increase in cortisol secretion is the increased mobilization of fatty acids from fat cells (Adipose tissue).
Starvation occurs when an animal doesn't feed due to unavailability of food. The body system makes use of stored glycogen which is synthesized to glucose by hormonal secretion of glucagon by the pancreas.
However, when the glucose converted is finished. Cortisol is secreted, which then initiate the mobilization of fatty acids as source of energy from the adipose tissues (fat cells) in the body system.
Answer:
viral envelope
The phospholipids in the viral envelope are similar to those in the plasma membrane of an infected host cell. The viral envelope is, in fact, derived by budding from that membrane, but contains mainly viral glycoproteins.
Answer:
8. D
9. A
10. A
11. C
12. D
Explanation:
8. Natural selection works on variation that exists in the genes of organisms. Antelopes who have genetic variation that makes their legs more muscular are at an advantage because they can outrun predators. This increases the chance that they will reach reproductive age, and be able to pass this advantageous trait onto their offspring. Over time, this selection pressure makes the variant more common in a population.
9. Beneficial traits are those that give a selective advantage. This could be one that helps it outrun predators (like above), avoid illness and death, gives it a reproductive advantage (i.e. more attractive to mates), or makes it better able to digest certain foods, for example. The formation of cancer cells would be harmful for an organism, reducing its fitness and perhaps leading to death. The inability to reproduce would mean genetic info is not passed on to the next generation, and stopping the production of an essential protein would likely lead to death. However, resistance to a virus would help an organism avoid illness and death, improving fitness.
10. Genotypes are what organisms inherit from their parents, i.e. the genetic information that is passed on. However, the way in which different alleles interact and are expressed is the phenotype. If we take the above example, natural selection is acting on the phenotype of muscular legs. If an antelope had the muscular leg genotype but for some reason it was not being expressed (maybe another gene is interfering with it), then the antelope would not have a selective advantage, and natural selection could not be act on the trait.
11. A trait that better suits an organism to its environment will be selected for by natural selection. This is because that organism is more likely to survive due to the trait, giving it a selective advantage. Therefore, if a mutation arose making the giraffe more adapted to the environment, it would be positively selected for, and through evolution would become more common.
12. This is an example of selective breeding, which has been happening for generations. Farmers spot desirable traits, and cross horses with these traits in an attempt to enhance the trait or to ensure it is passed on to the next generation. This is not natural selection, because farmers are making it happen artificially. It is not cloning or recombinant DNA, which are terms scientists use for actually manipulating the DNA in the lab.
