Module Two, Lecture Eleven

Question 1

What is the Genetic Code?

Answer 1

Is a system where specific sequences of nucleotides ( A, C, G, and T in DNA OR A, C, G and U in RNA ) dictate the order of amino acids in a protein

Question 2

Describe the Genetic Code… ( 3 )

Answer 2

1. DNA carries the information
2. The RNA is the messenger
3. The Protein is the worker

Question 3

How is DNA translated to RNA?

Answer 3

DNA contains the instructions for building proteins, these instructions are transcribed into RNA ( mRNA )

Question 4

How is mRNA translated to Proteins?

Answer 4

mRNA is then read in three-nucleotide units called codons. Each codon corresponds to a specific amino acid

Question 5

How are Codons translated to Amino Acids?

Answer 5

The genetic code is a “triplet code”, meaning each codon specifies one amino acid

Question 6

How do you read the Genetic Code?

Answer 6

The mRNA is read by ribosomes, which “translate” the codons into the corresponding amino acids, linking them together to form a polypeptide chain ( a protein )

Question 7

What is a Ribosome?

Answer 7

A complex molecule machine found in all living cells that plays a crucial role in protein synthesis, reading messenger RNA ( mRNA ) to build proteins from amino acids

Question 8

Describe the structure / function of a Ribosome… ( 4 )

Answer 8

1. Responsible for translating the genetic code carried by mRNA into a specific sequence of amino acids, which then fold to form proteins
2. Ribosomes are composed of two subunits, a small and a large subunit, each containing ribosomal RNA ( rRNA ) and proteins
3. They can be found either free-floating in the cytoplasm or attached to the endoplasmic reticulum ( ER ) in eukaryotic cells
4. Essential for living cells, as they are the machinery that produces the protein necessary for cellular function and survival

Question 9

What is Translation?

Answer 9

Is the process where genetic information encoded in mRNA is used to synthesize a specific protein, occurring in three main stages: inition, elongation, and termination

Question 10

In terms of Translation, what is Initiation?

Answer 10

A small ribosomal subunit attaches to the mRNA molecule, guided by specialised initiation factors, and the large subunits joined to form a functional ribosome

Question 11

In terms of Translation, what is Elongation?

Answer 11

The ribosome moves along the mRNA, matching codons with complementary anticodons on tRNA molecules that carry specific amino acids

Question 12

In terms of Translation, what is Termination?

Answer 12

When the ribosome encounters a stop codon, the complete peptide ( protein ) is released

Question 13

What is a Genotype?

Answer 13

Set of genes and / or DNA combinations that are responsible for a particular trait, determined at DNA level

Question 14

What is a Phenotype?

Answer 14

The physical expression, or characteristics of a genotype, e.g. are traits or characteristics of an organism that can be observed. Defined by what happens at protein level ( together with environmental influences )