What is a cell's genome?
Its complete set of genetic material, including all its genes and non-coding DNA.
AQA A-Level Biology - (7402) · 3.4.2
Revise AQA A-Level Biology - (7402) specification point 3.4.2, DNA and protein synthesis, with free active-recall flashcards. Flip through the set or review every question and answer below.
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What is a cell's genome?
Its complete set of genetic material, including all its genes and non-coding DNA.
What is a gene?
A DNA sequence that can contribute to the production of a functional product.
What is a cell's proteome?
The full range of proteins the cell is able to produce.
Why can cells with the same genome have different proteomes?
Different genes are expressed in different cells.
What is the basic structure of messenger RNA (mRNA)?
A single-stranded nucleic acid made of a chain of nucleotides.
What are the three components of an mRNA nucleotide?
Ribose sugar, phosphate and a base.
What are the four bases found in mRNA?
Adenine, uracil, cytosine and guanine.
What does the sequence of bases in mRNA determine during translation?
It carries information in codons that determines the amino acid sequence of a polypeptide.
What is the strand structure of tRNA, and how is it folded?
A short, single RNA strand folds through complementary base pairing between parts of the same strand.
What is a tRNA anticodon?
A sequence of three bases that can pair with a complementary mRNA codon.
What attaches to a tRNA’s amino acid attachment site?
A specific amino acid.
What does tRNA link an mRNA codon to?
The amino acid added to a growing polypeptide.
What does transcription produce?
An RNA copy of a DNA sequence.
What are the main steps of transcription?
How do the immediate products of transcription differ in prokaryotes and eukaryotes?
Prokaryotes produce mRNA directly; eukaryotes produce pre-mRNA.
What happens to introns and exons when eukaryotic pre-mRNA is spliced?
Introns are removed and exons are joined to form mRNA.
What does translation produce, and what determines its sequence?
A polypeptide, whose amino acid order is specified by the codon sequence in mRNA.
How does the ribosome bring successive mRNA codons into position during translation?
It binds to the mRNA and moves along it.
How do tRNAs match amino acids to mRNA codons during translation?
Each tRNA carries a specific amino acid and pairs its anticodon with a complementary mRNA codon.
How does the ribosome link amino acids during translation?
It brings the amino acids together so that peptide bonds form.
When does translation end?
When a stop codon is reached.
What role does ATP have in preparing tRNAs for translation?
It supplies energy for attaching amino acids to their corresponding tRNAs.
What relationship does the genetic code specify?
It relates the base sequence of a nucleic acid to the amino acid sequence of a polypeptide.
How is an mRNA sequence divided into codons?
It is read in consecutive, non-overlapping triplets of bases.
What can an mRNA codon specify?
An amino acid or a stop signal.
Can more than one codon specify the same amino acid?
Yes. Different codons can specify the same amino acid.
How can you determine a polypeptide sequence from an mRNA sequence using genetic-code information?
Identify the reading frame, divide the mRNA into codons, then use the genetic-code information to find the corresponding amino acids.
How do you obtain the mRNA sequence from a DNA template sequence?
Convert the DNA template sequence to its complementary mRNA sequence.
How does a DNA coding-strand sequence compare with its mRNA sequence?
The sequences match except that DNA has thymine where mRNA has uracil.
How should you interpret data from an experiment investigating a nucleic acid’s role?
Identify what was changed or compared, examine the measured results and any control, and relate the observed differences to the claim.
What three conclusions can experimental evidence lead to about a proposed role of a nucleic acid?
The results support, contradict, or do not resolve the proposed role.