Biological Molecules: Protien synthesis

Question 1

Protein synthesis is a 2 part process

Answer 1

Transcription followed by Translation

Question 2

Transcription is the first step this involves

Answer 2

Copying a DNA sequence to make an RNA molecule

Question 3

The main enzyme involved in transcription is _______

it’s function is to

Answer 3

RNA polymerase

Link nucleotides to form an RNA strand

Question 4

Transcription has 3 stages

Answer 4

• Initiation
• Elongation
• Termination

Question 5

Initiation is when RNA ______ binds to a section of DNA called the ______ found near the beginning of a ____. Once bound the RNA ______ separates the DNA strand providing the _____ ____ _______.

Answer 5

Polymerase
Promoter
Gene
Polymerase
Single Strand Template

Question 6

Elongation is when The template strand acts as a template for the RNA polymerase as it ______ it one base at a time. The polymerase builds an RNA ______ out of ______ _______. The RNA transcript contains the same information as the non-template strand of DNA but instead uses the base _____ (U) instead of Thymine (T)

Answer 6

Reads
Molecule
Complimentary nucleotides
Uracil

Question 7

Termination is when sequences called ______ signal that the RNA ______ is complete. Once they are transcribed, the cause the _______ to be ______ from the RNA polymerase. Finally creating the molecule known as mRNA.

Answer 7

Terminators
Transcript
Transcript
Released

Question 8

mRNA facts

• Transfers info from DNA in the nucleus to the …
• Is complimentary to the ______ strand
• Leaves the nucleus via …

Answer 8

• Cytoplasm
• Anti-sense
• Nuclear pores

Question 9

There are 3 different types of RNA what are they?

Answer 9

mRNA = messenger 
tRNA = transfer
rRNA = ribosomal

Question 10

tRNA facts

• ______ stranded polynucleotide
• Folded into a _______ shape stabilised by ____________ bonds between complimentary base pairs
• Each tRNA contains 3 unpaired bases at its base called _________
• Each of these is ________ to one _____ on mRNA

Answer 10

• Double
• Clover
• Phosphodiester bonds
• Anticodon
• Complimentary
• Codon

Question 11

Ribosomes are made of _____ and _____

Answer 11

• rRNA

- Proteins

Question 12

A ribosome binds the the ______ so that ___ bases (2 codons) are exposed to the the large subunit at the same time.

Answer 12

• mRNA

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Question 13

What is the first codon (start codon) and what aa does the tRNA with this anticodon carry?

Answer 13

AUG

methionine (met tRNA)

Question 14

When the met tRNA binds to the first 3 bases on the mRNA what bond does it form and where?

Answer 14

It forms a H-Bond between it’s anticodon and its complimentary bases.

Question 15

After met tRNA another tRNA binds to the next 3 bases via the same process. 2 aa are next to each other. What bond is formed between the bond using what enzyme?

Answer 15

They form a peptide bond with the enzyme peptidyl transferase.

Question 16

This process of binding and the formation of a polypeptide chain continues until a “stop” anticodon is introduced. What are these anticodons and why do they stop the process?

Answer 16

The “stop” anticodons are UAA, UAC, UAG and they stop the process as they have no complimentary anticodon.