Answer:
The main function of the RB protein is to inhibit the transition from the G1 to S phase. Its activity depends on its phosphorylation state: if RB is not phosphorylated (active state), it is bound to the transcription factor E2F, preventing its translocation to the nucleus and the activation of genes necessary for DNA synthesis; and if it is phosphorylated, by cyclin-CDK complexes, E2F is released and cell proliferation occurs.
Explanation:
Retinoblastoma (Rb) was the first tumor suppressor described and, as we know today, mutations in its structure determine a large number of cancers. Structurally, we speak of a large and multifunctional protein; which is organized in different domains. The activity of this protein is regulated, mainly, by phosphorylation at multiple sites described over the years and is involved in control mechanisms of the cell cycle, apoptosis and senescence.
Answer:
Nucleic Acids:
- Uracil
- Adenine
- Guanine
- Cytosine
Explanation:
Since we only have one strand shown, I'm going to assume it is RNA. Both DNA and RNA have nucleic acids, but RNA has 1 different nucleic acid; it replaces Thymine with Uracil. So the 4 nucleic acids are uracil, adenine, guanine, and cytosine.
If the picture shown is a cross-section of DNA, then our 4 nucleic acids are adenine, thymine, guanine, and cytosine.
Answer:
Since, the original DNA sequence has not been provided, the mutation can be an insertion/deletion or a frameshift mutation.
- Mutated DNA
- Frameshift mutation/ insertion or deletion
- All the amino acids changed after the point mutation
Explanation:
Frameshift Mutation:
- A frameshift mutation is the alteration in the reading frame of the DNA due to the addition/deletion of one or two nucleotides.
- This type of mutation moves the mRNA sequence one or two bases forwards or backwards which disrupts the three base codons sequence required for translation into proteins.
- The CT at the end of the sequence is indicative of a frameshift in the DNA reading frame.
- Frameshift mutation affect all amino acids in a polypeptide chain as all codons are moved one or two steps forwards or backwards.
Answer:
TRANSCRIPTION
Explanation:
Transcription is the first process that occurs in the expression of a gene. It involves the synthesis of a mRNA molecule from a DNA template. The DNA molecule, which is located in the nucleus of an eukaryotic cell, is bound to by an enzyme called RNA polymerase in order to synthesize an mRNA molecule/strand.
RNA polymerase synthesizes a mRNA molecule using complementary base pairing rule i.e. Uracil base (U) is synthesized when Adenine (A) is read, Adenine when Thymine (T) is read, Guanine (G) when cytosine (C) is read, Cytosine when guanine is read. These nucleotide bases are then joined together via chemical bonding.
In a nutshell, RNA polymerase catalyzes the formation of a bond between the backbone sugar of one nucleotide base to the backbone phosphate of another nucleotide base in the metabolic process of TRANSCRIPTION.
