What is protein synthesis?

Question 1

What is protein synthesis?

Answer 1

Protein synthesis is the process by which cells make proteins, using instructions from DNA carried by RNA.

Question 2

What are the 2 steps of protein
synthesis?

Answer 2

1. Transcription (DNA → mRNA)
2. Translation (mRNA → protein)

Question 3

Describe each step of the protein
synthesis.

Answer 3

DNA —> Transcription —> mRNA —-> Translation — protein.

Question 4

what is RNA polymerase

Answer 4

RNA polymerase is an enzyme that helps make RNA by copying a specific section of DNA during transcription. It binds to the DNA at the promoter and moves along the strand, creating an RNA molecule based on the DNA sequence.

Question 5

What is the promoter

Answer 5

A promoter is a specific region of DNA that signals where RNA polymerase should bind to start transcription. It’s like a starting point for making RNA.

Question 6

What happens from DNA to mRNA through the steps of?

Answer 6

Transcription is the first step of gene expression/protein synthesis

It is broken into three major steps:
Step 1: Initiation
Step 2: Elongation
Step 3: Termination

Question 7

Transcription:

Initiation

Answer 7

• Beginning of transcription

1. It occurs when the enzyme RNA polymerase binds to a region of a gene called the promoter
2. This signals the dNA to unwind so the enzyme can “ read” the bases in one of the DNA strands
   ( this is known as the Template strand) “
3. The enzyme is now ready to make a strand of mRNA with a Complementary sequence of bases.

Question 8

Where initiation happens in each step.

Answer 8

DNA unwinds: Inside the nucleus, the DNA double helix unwinds at the gene’s promoter region.

Promoter binding: RNA polymerase binds to the promoter on the DNA, also in the nucleus.

Transcription: RNA polymerase moves along the DNA in the nucleus, making an RNA copy.

RNA leaves the nucleus: After transcription, the newly made RNA (usually mRNA) leaves the nucleus and moves to the cytoplasm, where it helps make proteins.

HERE
- Initiation is the beginning of transcription, It occurs when the enzyme RNA polymerase binds to a region of a gene called the promoter

• This signals the DNA to unwind so the enzyme can “ read” the bases in one of the DNA strands
  ( known as the Template strand )
• The enzyme is now ready to make a strand of mRNA with a complementary sequence of bases

Question 9

Transcription:

Elongation

Answer 9

During elongation in transcription, RNA polymerase moves along the DNA and builds the mRNA strand by adding matching RNA nucleotides to the growing chain. It’s like copying the DNA’s code to make mRNA.

3. Adenine pairs with uracil and cytosine pairs with Guanine

Question 10

transcription:

Termination

Answer 10

1. termination is the ending of transcription and occurs when RNA polymerase crosses a Termination sequence in the gene.
2. The mRNA strand is complete, and it detaches from DNA
3. The mRNA strand is now ready to leave the nucleus, travel into the cytoplasm, attach to a ribosome and be turned into a protein.

Question 11

Anticodon

Answer 11

3 nucleotide sequence found on the tRNA that binds to the mRNA sequence

Question 12

Steps 5- 6 Translation

Answer 12

5. A peptide bond forms between the adjoining amino acids, forming a polypeptide. The tRNA is removed to be used again.
6. The protein production stops when a STOP codon is reached. The mRNA breaks away from the ribosome.

Question 13

Codon

Answer 13

3 nucleotides found on the mRNA that codes for the specific amino acid

Question 14

What do Codons do

Answer 14

Codons code for a specific amino acid, they are brought to the ribosome by tRNA and linked together to form a long polypeptide chain (protein)

Question 15

peptide bond

Answer 15

• The chemical link that connects two amino acids together to form a protein.
• During translation, the ribosome helps amino acids join together with peptide bonds, building the protein chain.

Question 16

What is a polypeptide

Answer 16

A polypeptide in translation is a chain of amino acids linked together by peptide bonds. This chain will fold to become a protein once translation is complete.

Before it’s folded into a protein.

Question 17

What are the Steps in Translation 1- 2

Answer 17

1. The mRNA moves through the nuclear pore to the cytoplasm.
2. The mRNA moves through the nuclear pore to the cytoplasm.
   The mRNA attaches to the ribosome. The ribosome moves along the mRNA strand, reading 3 nucleotides (codon) at a time. Translation begins at the START codon.

The START codon is always AUG!

Question 18

Steps 3- 4 in Translation

Answer 18

3. After reading the START codon transfer RNA (tRNA) molecules transport the amino acids to the mRNA strand at the ribosome.

( Transfer RNA (tRNA) molecules carry the amino acids to the mRNA at the ribosome )

4. 4. tRNA links with the ribosome and matches its anticodon with the codon of the mRNA

Question 19

What is involved? in protein synthesis

Question 20

Where does this occur
in the cell? in protein synthesis

Question 21

What is mRNA?

Answer 21

Stands for messenger RNA. It is the main molecule associated with transcription.

• mRNA carries the instructions for one gene
• mRNA is synthesised in the nucleus
• Its function is to make a copy of a gene and take it to a ribosome, where amino acids are assembled to make a protein

Question 22

What is the difference between RNA and mRNA

Answer 22

there is a difference:

RNA is a general term for ribonucleic acid, which can take various forms in the cell.

mRNA (messenger RNA) is a specific type of RNA that carries the instructions from DNA to the ribosome, where proteins are made.

Question 23

How is mRNA
paired with DNA?

Answer 23

• mRNA pairs with DNA by matching its bases to the DNA’s bases. In transcription.
• This happens when RNA polymerase reads the DNA and builds the mRNA strand.

Question 24

What are
the bases?

Question 25

What is the role of the ribosome?

Answer 25

The ribosome reads the mRNA and builds a protein by linking amino acids together during translation. It’s like a factory that assembles proteins.

Question 26

Be able to use the mRNA codon table for amino acids

Question 27

What is a polypeptide chain? How is this different to a protein?

Answer 27

A polypeptide is just a chain of amino acids.

A protein is a fully folded and functional molecule, often made up of one or more polypeptide chains that have been folded and sometimes combined with other molecules.

Question 28

What is tRNA?

Answer 28

tRNA (transfer RNA) is a molecule that helps build proteins during translation.

Question 29

What is the role of tRNA?

Answer 29

Its role is to carry specific amino acids to the ribosome, where it pairs with the mRNA using its anticodon, matching the correct amino acid to the mRNA codon.

Question 30

What is a triplet.

Answer 30

In DNA, it’s called a triplet (a group of three nucleotide bases).

When transcribed into mRNA, it’s called a codon.

Question 31

Be able to transcribe DNA to mRNA.

Question 32

Be able to translate mRNA to amino acids using the codon table.
- Remember to always find AUG first.

Question 33

What are the STOP codons

Answer 33

STOP Codons are UAA, UGA, UAG

They are STOP Codons because they don’t code for an amino acid.