Proteins Synthesis & Enzymes

Question 1

What are the roles of genes?

Answer 1

Genes contain the code for the production of proteins and dictates the order and number of amino acids

Question 2

Where are genes housed?

Answer 2

in DNA molecules

Question 3

What is a gene?

Answer 3

A section of the DNA strand that contains hereditary material and codes for specific proteins

Question 4

Describe how DNA is constructed and packaged

Answer 4

• The DNA double helix is wrapped around histone proteins creating a nucleosome
• Nucleosomes are linked together to form chromatin
• Chromatin groups form chromatin fibres

Question 5

What is the function of mRNA?

Answer 5

It copies the DNA gene in the form of mRNA which is able to leave the nucleus

Question 6

Explain the process of transcription

Answer 6

Rough endoplasmic reticulum guides mRNA copy from nucleus to a ribosome
Ribosomes will read the mRNA copy and place amino acids carried on tRNA in correct sequence
This builds the polypeptide (protein) chain

Question 7

Define the transcription process

Answer 7

• DNA uncoils and histones detach
• Copy of DNA is made
• It is also called gene activation/expression

Question 8

What roles does RNA polymerase have?

Answer 8

• It binds to the start (promoter) region of gene
• It ‘reads’ the bases on the template strand of DNA
• Adds complimentary bases from nucleoplasm to form mRNA chain

Question 9

What ends transcription?

Answer 9

When the RNA polymerase reaches the ‘stop’ signal

Question 10

Define codon

Answer 10

• Sequence of three bases on mRNA

- Each codon specifies a particular amino acid

Question 11

What percentage of mRNA ever reaches the cytoplasm?

Answer 11

5%

Question 12

Define the translation process

Answer 12

Process of making a polypeptide chain from mRNA

Question 13

Define enzymes

Answer 13

Catalysts that accelerate biological reactions