The Genetic Code Flashcards Preview

DNA, RNA and Protein Synthesis - Biology - Alevel > The Genetic Code > Flashcards

Flashcards in The Genetic Code Deck (17)
1

What does the sequence of bases on DNA code for?

The sequence of amino acids in proteins.

2

What is a codon?

Sequence of 3 nucleotides which together form a unit of genetic code in DNA or RNA.

3

Each codon codes for...

One amino acid.

4

How many codons are there?

64.

5

What is the meaning of the 64 codons called?

The genetic code.

6

What does it mean by degenerate code?

Many instances in which different codons specify the same amino acid.

7

What is the start of the gene sequence?

AUG - Methinonine.
All proteins start with this, can be removed later.

8

Where is the code read from?

5 prime to 3 prime.
Protein is made from the N to C terminus.

9

What is the genetic code?

Its the sequence of base triplets in mRNA which code for specific amino acids.

10

Base triplets don't share their bases meaning the code is...

Non-overlapping.

11

How many amino acids is there compared to codons?

20 amino acids 64 codons.

12

Some amino acids are coded by more than one base, give an example.

Tyrosine, it can be coded for by UAU or UAC.

13

Not all codons code for amino acids, give an example of what else they code for?

Some codons are used to tell the cell when to stop production of protein. - stop signals.

14

Where are stop signal found?

At the end of the mRNA.

15

What does it mean by the genetic code is universal?

The same specific base triplets code for the same amino acids in all living organisms.

16

EXAMPLE , what does UAC code for?

Tyrosine in all organisms.

17

The same genetic code is found in all organisms on Earth, what does this suggest?

Indirect evidence for evolution as it suggets the code may have been preserved from a common ancestor of all living organisms.