Answer:
p53 helps the cells from passing on mutations that lead to DNA damage. Hence, it is known as the guardian angel of the cell as it helps fight against cancer. However, if p53 becomes defective or missing, then the mutations will lead to cancer.
Mutations in the p53 can also cause the tumor-suppressing genes to convert into tumor causing genes. Hence, mutations in such kind of genes can be very harmful for the body.
Several genes determine your skin color; this is a DNA-generated phenotype. However, if you spend a lot of time in the sun, your skin will be darker. This is an environmental influence on your phenotype.
Answer:
From the point of view of the type of molecule that is obtained after the degradation of the hydrocarbon skeleton, amino acids can be classified as: glucogenic and ketogenic. The main difference between glucogenic amino acids and ketogenic amino acids is that glucogenic amino acids can be converted to pyruvate or other glucose precursors, while ketogenic amino acids can be converted to acetyl CoA and acetoacetylCoA.
Explanation:
Glucogenic amino acids are amino acids that break down to pyruvate, alpha-ketoglutarate, succinyl Co-A, fumarate, and oxaloacetate and are so named because the synthesis of glucose from these molecules is feasible. Both pyruvate and the Krebs cycle intermediates noted above can be converted to phosphoenolpyruvate and subsequently glucose through gluconeogenesis.Ketogenic amino acids are the amino acids that generate acetyl-CoA or acetacetyl-CoA and are called by this name because they can cause ketone bodies. Since mammals lack the proper enzyme system, these compounds can never be used as precursors for glucose biosynthesis. Of the twenty universal amino acids, fourteen are purely glucogenic and two are purely ketogenic (leucine and lysine). The remaining four (isoleucine, phenylalanine, tryptophan and tyrosine) are glucogenic and ketogenic simultaneously since a part of the hydrocarbon skeleton originates precursors for the biosynthesis of glucose (pyruvate or Krebs cycle intermediates) and the other part acetyl-CoA or acetacetyl -CoA.
