Genes and Proteins - Chapter 14

Flashcards about genes and proteins, including the processes of transcription and translation.

What is the basic unit of heredity?

A gene

What is the process by which DNA directs the synthesis of proteins?

Gene expression

What is synthesized from a DNA template during transcription?

RNA

In RNA, which nucleotide base is used instead of Thymine (T)?

Uracil (U)

What enzyme binds to the template strand during transcription to create a complementary RNA sequence?

RNA polymerase

What are the three steps of transcription?

Initiation, Elongation, Termination

What region of DNA does RNA polymerase bind to during transcription initiation?

Promoter

During transcription elongation, to which end of the DNA does the 3' end of RNA match?

5' end

In eukaryotes, what sequence does RNA polymerase II transcribe to trigger RNA processing?

Polyadenylation sequence

What structures are added to the 5' and 3' ends of mRNA during RNA processing to protect it from degradation?

Cap and poly-A tail, respectively

What are the sequences in genes that are not used for producing a protein and are removed from mRNA during RNA processing called?

Introns

What molecule synthesizes a polypeptide (protein) from an RNA template?

Ribosome

What is the name of three-letter words of the language of DNA?

Codon

What kind of code refers to the fact that different triplets can code for the same amino acid?

Degenerate code

What molecule carries amino acids to the ribosome during translation?

Transfer RNA (tRNA)

What enzyme catalyzes covalent bond formation between the tRNA and the correct animo acid?

Aminoacyl-tRNA synthetases

In translation, what does the anticodon on the initiator tRNA molecule match up with?

The START codon in mRNA

During translation termination, what binds to the stop codon, bringing in a water molecule and triggering hydrolysis of the polypeptide from the tRNA?

Release factor

What is the name for strings of ribosomes that can be seen with an electron microscope?

Polyribosomes (or polysomes)

What sequence is used to allow RNA to base pair with itself forming a 'hairpin' during Rho-independent transcription termination in prokaryotes?

Repetitive C-G sequence

In the context of protein mutations, what is the term for the original nucleotide sequence?

Wild type

What is the name for changes in codons that do not change the amino acid?

Synonymous substitutions (aka silent mutations)

What are alternative versions of the same gene called?

Alleles

Beadle and Tatum revised the one gene-one enzyme hypothesis to what?

The one gene-one polypeptide hypothesis