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Biology OCR (3, biological molecules) > Protein synthesis > Flashcards

Flashcards in Protein synthesis Deck (24)
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1

How many bases code for an amino acid?

3

2

What do you call three base pairs collectively?

A codon

3

What comes first during protein synthesis, translation or transcription?

Transcription

4

Where does DNA live?

Inside of the nuclear envelope

5

Why is it important that the DNA can not leave the nuclear envelope?

So that the DNA can not get damaged in the cytoplasm

6

What organelle undergoes protein synthesis?

The ribosomes

7

What is the role of the enzyme helicase during transcription?

Helicase 'unzips' a segment of the DNA at the start codon by breaking the hydrogen bonds between the base pairs.

8

Only one strand of the DNA codes for a protein. What is the name of this strand?

The sense strand

9

Which way does the sense strand go?

5' to 3'

10

The other strand of DNA contains the complementary base pairs for the sense strand. What is the name of this strand?

The antisense strand

11

What does the antisense strand act as during protein synthesis?

A template strand (so that the RNA formed is the same as the sense strand)

12

What happens after the DNA molecule 'unzips'?

Free RNA nucleotides then pair with the complementary bases on the antisense strand.

13

On RNA what does the base thymine get replaced by?

Uracil

14

What base does uAracil bind to?

Adenine

15

What does the enzyme RNA polymerase do after RNA is formed?

It creates phosphodiester bonds between the RNA nucleotides

16

What is the name of the RNA molecule that is formed during transcription?

Messenger RNA (mRNA)

17

How does the mRNA leave the nucleus?

Through a nuclear pore

18

After the mRNA molecule leaves the nucleus where in the cytoplasm does it travel to?

The mRNA molecule travels to a ribosome (in order to begin translation)

19

What are ribosomes made from?

Ribosomal RNA (rRNA)`

20

What is special about ribosomal RNA in regards to protein synthesis?

ribosomal RNA maintains the structural stability of the protein synthesis sequence. It also catalyses the reaction.

21

Another RNA molecule has the job of translating the mRNA. What is the name of this RNA?

Transfer RNA (tRNA)

22

Draw and label the structure of a transfer RNA molecule

Check page 77

23

What does the tRNA molecule do in regards to protein synthesis?

The tRNA molecule carries an amino acid in relation to its 3 anticodons at the end of the molecule. These anticodons match up with the codons on the mRNA molecule which then bind together. The amino acids on the end of the tRNA molecule are added one at a time and a polypeptide chain grows as the tRNA molecules move off. Thus the protein chain is made.

24

What are the names of the three RNA molecules?