Question

1. what is the central dogma of biology?
2. in terms of homeostasis, why are proteins important?
3. determine how the mutations below will affect each amino - acid sequence. use the mrna codons in the table of your text to complete items a - d below. in the space provided, write the names of the amino acids that correspond to each mrna sequence and mutation given.

example:
mrna sequence ugu - ccg
mutation sequence ugc - cgc
cysteine - proline
cysteine - arginine
a. mrna sequence gaa - cgu
mutation sequence gau - cgu

b. mrna sequence auc - ugc
mutation sequence auc - ugg

c. mrna sequence ugu - ccu - ccu
mutation sequence ugu - uuc - ccu

d. mrna sequence ggg - uua - acc
mutation sequence ggu - uaa

1. what kind of mutation occurred to the mrna sequence in item d above? explain.

Explanation:

Step1: Define central dogma

The central dogma of biology is the flow of genetic information from DNA to RNA to protein. DNA is transcribed into RNA by RNA - polymerase, and then RNA is translated into proteins at ribosomes.

Step2: Explain protein importance in homeostasis

Proteins are important in homeostasis as enzymes (catalyze biochemical reactions), transporters (move substances across cell membranes), and as structural components (maintain cell shape and integrity). They also act as hormones and receptors for cell - cell communication which is crucial for maintaining stable internal conditions.

Step3: Translate mRNA to amino acids for a

Using the codon - amino acid table: GAA codes for glutamic acid, GAU codes for aspartic acid, and CGU codes for arginine. So the original is glutamic acid - arginine and the mutated is aspartic acid - arginine.

Step4: Translate mRNA to amino acids for b

AUC codes for isoleucine, UGC codes for cysteine, and UGG codes for tryptophan. So the original is isoleucine - cysteine and the mutated is isoleucine - tryptophan.

Step5: Translate mRNA to amino acids for c

UGU codes for cysteine, CCU codes for proline, and UUC codes for phenylalanine. So the original is cysteine - proline - proline and the mutated is cysteine - phenylalanine - proline.

Step6: Translate mRNA to amino acids for d

GGG codes for glycine, UUA codes for leucine, ACC codes for threonine, GGU codes for glycine, and UAA is a stop codon. So the original is glycine - leucine - threonine and the mutated is glycine - stop.

Step7: Identify mutation in d

The mutation in d is a frameshift mutation. The deletion of the second 'G' in GGG and the deletion of ACC shifts the reading frame of the codons, leading to a premature stop codon (UAA) and a truncated protein.

Answer:

1. The central dogma of biology is the process by which genetic information flows from DNA to RNA (transcription) and then from RNA to protein (translation).
2. Proteins are important in homeostasis as enzymes, transporters, structural components, hormones, and receptors for cell - cell communication.

4.
a. Original: glutamic acid - arginine; Mutated: aspartic acid - arginine
b. Original: isoleucine - cysteine; Mutated: isoleucine - tryptophan
c. Original: cysteine - proline - proline; Mutated: cysteine - phenylalanine - proline
d. Original: glycine - leucine - threonine; Mutated: glycine - stop

1. The mutation in item d is a frameshift mutation. The deletion of nucleotides shifts the reading frame of the codons, resulting in a premature stop codon and a truncated protein.