2.1.3: Nucleotides And Nucleic Acids

Question 1

What is the function of RNA polymerase?

Answer 1

Joins together adjacent RNA nucleotides to form a new mRNA polymer chain

RNA polymerase catalyzes the formation of phosphodiester bonds between RNA nucleotides.

Question 2

What role does DNA helicase play in transcription?

Answer 2

Breaks the hydrogen bonds between the bases in the two strands of DNA

This unwinds the DNA helix and allows one strand to act as a template.

Question 3

What happens to mRNA after it is copied from DNA?

Answer 3

It is modified and leaves the nucleus through the nuclear envelope pores

This process occurs after a gene has been transcribed.

Question 4

What is the start codon in the translation process?

Answer 4

The codon where modified mRNA attaches to the small subunit of the ribosome

The start codon is typically AUG.

Question 5

What is the function of tRNA in translation?

Answer 5

Aligns opposite the mRNA with complementary anticodon and delivers amino acids

tRNA holds the amino acids that will be joined together to form a polypeptide.

Question 6

Fill in the blank: The ribosome can hold ______ tRNA molecules at a time.

Answer 6

two

Question 7

What type of bond is formed between amino acids during translation?

Answer 7

Peptide bond

The formation of peptide bonds is catalyzed by an enzyme using ATP.

Question 8

What happens when the ribosome reaches the stop codon?

Answer 8

The ribosome detaches and ends translation

This marks the end of the polypeptide chain synthesis.

Question 9

What happens to the polypeptide chain after translation?

Answer 9

It enters the Golgi body for folding and modification

This is crucial for the final functional structure of the protein.

Question 10

Define ‘nucleotide’.

Answer 10

The basic building block of nucleic acids

Nucleotides consist of a sugar, a phosphate group, and a nitrogenous base.

Question 11

What is the role of ATP in translation?

Answer 11

Provides energy for the formation of peptide bonds

ATP is essential for various enzymatic processes during translation.

Question 12

What is the function of the small subunit of the ribosome?

Answer 12

Attaches to the modified mRNA at the start codon

It plays a critical role in the initiation of translation.

Question 13

What are the two main processes involved in gene expression?

Answer 13

• Transcription
• Translation

Question 14

True or False: The polypeptide chain is assembled inside the nucleus.

Answer 14

False

The polypeptide chain is assembled in the cytoplasm at the ribosome.