3/12 (nucleic acids and proteins)

Question 1

What are nucleic acids?
2 marks

Answer 1

Large biomolecules that play important roles in all cells.
Such as storing genetic information for creating RNA and proteins in cells.

Question 2

What are the two main types of nucleic acids?
2 marks

Answer 2

DNA (deoxyribonucleic acid)
RNA (ribonucleic acid)

Question 3

DNA
2 marks

Answer 3

stores and translates genetic information.
the sequence of nucleotides in DNA is used to code for products.

Question 4

three components of nucleic acids
3 marks

Answer 4

Deoxyribose sugar (DNA) or ribose sugar (RNA)
- Phosphate molecule
- Nitrogenous base (thymine or uracil, guanine, cytosine, adenine)

Question 5

what are nucleotides
1 mark

Answer 5

Nucleotides are the basic building blocks tha tmake up DNA and RNA.

Question 6

What is RNA? List the three types
4 marks

Answer 6

RNA (ribonucleic acid) is known to play a vital role in protein synthesis. The three types of RNA are:
- tRNA (transfer RNA)
- rRNA (ribosomal RNA)
- mRNA (messenger RNA)

Question 7

tRNA (transfer RNA)

Answer 7

Single stranded RNA molecules that transfer amino acids from the nucleus to the ribosomes to form part of the polypeptide chain. This happens when tRNA and mRNA interact through codons during protein synthesis.

Question 8

mRNA (messenger RNA)

Answer 8

It carries genetic information from the DNA in the nucleus to the ribosomes of the cell. mRNA is formed during the transcription of DNA in the nucleus.

Question 9

rRNA (ribosomal RNA)

Answer 9

Made in the nucleolus and combines with proteins to make ribosomes. Ribosomes are organelles that synthesise proteins during translation.

Question 10

What is protein synthesis?

Answer 10

The process where amino acids are linked together to form a polypeptide chain with the help of mRNA and tRNA.

Question 11

triplet/codon

Answer 11

triplet refers to the three nucleotides in DNA
codon refers to the three nucleotides in RNA

Question 12

Gene

Answer 12

Segments of DNA that codes for a trait or characteristic in an organism.

Question 13

transcription

Answer 13

The creation of mRNA by unwinding DNA and producing its complementary strand. One of the processes of protein synthesis.

Question 14

translation

Answer 14

When amino acids are formed through the translation of mRNA. This subprocess of protein synthesis takes place in:
- ribosomes.
- ER-bound ribosomes.

Question 15

promoter (gene)

Answer 15

The sequence of a gene that is recognised by RNA polymerase (protein) to initiate transcription.

Question 16

introns

Answer 16

segments of DNA that don’t code for anything and are spliced out of the mRNA

Question 17

extrons

Answer 17

segments of DNA that code for proteins.

Question 18

stop triplet

Answer 18

segments where the transcription ends. Does not code for an amino acid.

Question 19

gene expression

Answer 19

the process where information stored in a gene is used to synthesise (produce) a functional gene product such as RNA or protein.

Question 20

RNA processing

Answer 20

mRNA transcript is modified to increase the stability and alteration of the coding sequence.

Question 21

What are the three main steps in transcription?

Answer 21

• Initiation
• Elongation
• Termination

Question 22

Initiation (transcription)

Answer 22

Unzips the DNA through RNA polymerase by breaking hydrogen bonds.
It consists of a coding strand that does not get transcribed and a template strand that does get transcribed and is complementary to the mRNA produced.

Question 23

RNA polymerase

Answer 23

An enzyme that is responsible for copying the DNA sequence into the RNA.

Question 24

Elongation (transcription)

Answer 24

The primary transcript (mRNA) is formed by adding the complementary base pairs ( A, U, G, C) when the DNA is unwinded.

Question 25

Termination (transcription)

Answer 25

Transcription ends when RNA polymerase has reached the stop codon in the DNA and detaches due to the release factors that the stop codon produces.

Question 26

mRNA processing

Answer 26

the modifications made to the primary transcript.
an example of mRNA processing is splicing.

Question 27

splicing

Answer 27

A process where the extrons (coding regions or gene) are joined together to form mature RNA, eliminating the introns (non-coding regions)

Question 28

initiation (translation)

Answer 28

part of the process where the tRNA attached with an amino acid moves along the RNA strand to find it’s anticodon.

Question 29

elongation (translation)

Answer 29

amino acid, which has an attached anticodon, moves to the ribosome to attach to its codon. Elongates the amino acid chain.

Question 30

termination (translation)

Answer 30

elongation and initiation continue until the tRNA reaches a stop codon which terminates the process.