Chapter 39: The Genetic Code

Question 1

The pathway to protein synthesis is ____

Answer 1

Translation

Question 2

The language of _____ sequence is translated to the language of an _____ sequence.

Answer 2

Nucleotide

Amino Acid

Question 3

Process of translation requires a ____

Answer 3

Genetic Code

Question 4

The __ letter word of DNA (RNA) is translated to the ___ letter alphabet of proteins

Answer 4

4

20

Question 5

Nucleotides resemble ____

Answer 5

Letters

Question 6

Codons resemble _____.

Answer 6

Words

Question 7

Genes resemble _____.

Answer 7

Sentences

Question 8

Genome resembles _____.

Answer 8

Book

Question 9

Each codon is a _____ of nucleotides.

Answer 9

Triplet

Question 10

The genetic code is a collection of…

Answer 10

Codons

Question 11

For 20 AAs, there should be…

Answer 11

20 codons

Question 12

Each codon should have __ nucleotides to impact specificity to each amino acid for a specific codon

Answer 12

3 nucleotides
1 nuc used = 4 combinations
2 nuc = 16 combinations
3 nuc = 64 combinations

Question 13

What are the 4 characteristics of the Genetic Code?

Answer 13

Specificity, Universal, Redundant, Non-overlapping

Question 14

What does it mean for the genetic code to be specific?

Answer 14

A specific codon always codes for the same amino acid

e.g. UUU codes for Phenylalanine, it can never code for another AA

Question 15

What does it mean for the genetic code to be universal?

Answer 15

All living organisms have the same genetic code

Question 16

There is an exception to the universal rule in _____ codons. AUA codes for methionine instead of isoleucine and UGA codes for tryptophan instead of termination codon

Answer 16

Mitochondrial

Question 17

____ & ____ code for arginine in the cytoplasm but in the mitochondria they are termination codons

Answer 17

AGA & AGG

Question 18

Most organisms use the same genetic code because its important for production of

Answer 18

Recombinant proteins

Question 19

Some organisms have slight modifications - in ciliated protozoa, codons that are ___ signals in most organisms, encode ____.

Answer 19

Stop

Amino Acids

Question 20

______ also use variations of the genetic code

Answer 20

Mitochondria

Question 21

What does it mean for the genetic code to be redundant?

Answer 21

(degenerate) Although each codon corresponds to a single AA, a single AA can have multiple codons
(e. g. Tryptophan and Methionine have multiple codons)

Question 22

What does it mean for the genetic code to be non-overlapping?

Answer 22

All codons are independent sets of 3 nucleotides. There is no overlapping. Codon is read from fixed starting point as a continuous sequence of nucleotides, 3 at a time

Question 23

The starting point it extremely important and is known as the

Answer 23

Reading Frame

Translation of the correct message requires selection of the correct reading frame

Question 24

The sequence of bases is read sequentially from a fixed starting point until termination in a ___ to ___ direction

Answer 24

5’ to 3’

Question 25

What are the two types of codons?

Answer 25

Non Sense and Initiator

Question 26

What are non sense codons?

Answer 26

Codons that do not code for any AA. They are known as termination or stop codons as well

Question 27

What are the 3 non sense codons out of the 64 codons?

Answer 27

UAA
UAG
UGA

Question 28

What happens when a non sense codon is inserted into the growing polypeptide chain?

Answer 28

The ribosome pauses and falls off the mRNA

Question 29

What is the initiator codon in majority of proteins?

Answer 29

AUG

In a few cases, GUG may be used as the initiator code

Question 30

____ is the only AA specified by just one codon

Answer 30

Methionine

Question 31

Mutations can be explained using the

Answer 31

Genetic Code

Question 32

What are the two main types of mutations?

Answer 32

Point mutations & Frame Shift mutations

Question 33

What are the three types of point mutations?

Answer 33

Silent, Nonsense, and Missense

Question 34

Trichophalangeal syndrome type 1 (TRPS1) is due to

Answer 34

Frameshift mutation

Question 35

Clinical manifestations due to TRPS1

Answer 35

Hair loss, finger and toe malformation and facial deformities