Reploication

Question 1

What is translation?

Answer 1

The RNA directed synthesis of a polypeptide

Question 2

What interprets the code on an mRNA molecule?

Answer 2

tRNA

Question 3

What is the function of tRNA?

Answer 3

transfer amino acids from the cytoplasm to a ribosome

Question 4

How many amino acids are there?

Answer 4

20

Question 5

Are all tRNA molecules identical?

Answer 5

No, each codes for a particular mRNA codon in a particular amino acid

Question 6

On one end of the tRNA is the amino acid, what is at the other end?

Answer 6

Nucleotide triplet called an anticodon that base pairs with complementary codon of mRNA

Question 7

Where is tRNA transcribed?

Answer 7

From DNA in the nucleus

Question 8

What happens to the tRNA molecule once it has dropped an amino acid at the ribosome?

Answer 8

Recycled, goes to get another one

Question 9

What is a tRNA made of?

Answer 9

Single RNA strand, about 80 nucleotides long

Question 10

How does tRNA get its structure?

Answer 10

complementary stretches in the polypeptide can hydrogen bond

Question 11

Which end of the molecule does amino acid attach to?

Answer 11

3’ end

Question 12

What shape is tRNA?

Answer 12

3D Structure, 3 loops, l shaped

Question 13

What are the two recognition stages required for accurate translation?

Answer 13

Correct match between amino acid and tRNA and a correct match between the tRNA anticodon and mRNA codon.

Question 14

What enzyme is required to match up tRNA and amino acid?

Answer 14

Aminoacyl-tRNA synthetase

Question 15

How does the enzyme Aminoacyl-tRNA synthetase attach the tRNA and amino acid

Answer 15

active site of enzyme fits only a specific amino acid and tRNA combination, joins together by covalent bond using ATP hydrolysis

Question 16

How many different types of Aminoacyl-tRNA synthetase enzymes are there?

Answer 16

20

Question 17

How many different codons are there for amino acids?

Answer 17

61 different codons

Question 18

What can be seen from the fact that there are 61 different codons but 20 amino acids?

Answer 18

tRNA is able to bind to more than one different codon, wobbly base pairings, the third base pair rule is more relaxed

Question 19

What I the function of a ribosome?

Answer 19

Facilitates the specific coupling of tRNA anticodons with mRNA codons during protein synthesis

Question 20

What is a ribosome built from?

Answer 20

rRNA, Small and large subunits

Question 21

Where is rRNA made?

Answer 21

In the nucleus from chromosomal DNA

Question 22

When do the large and small subunits attach?

Answer 22

Only join to form a functional ribosome when they attach to mRNA in the cytoplasm

Question 23

What is the most abundant type of cellular RNA?

Answer 23

rRNA

Question 24

What are the components of a nucleotide monomer?

Answer 24

nitrogenous base, sugar molecule, phosphate group

Question 25

What are the two families of nitrogenous bases?

Answer 25

pyrimidines and purines

Question 26

Which bases are pyrimidines?

Answer 26

Cytosine and Thymine and Uracil

Question 27

Which bases are purines?

Answer 27

guanine and adenine

Question 28

How do you differentiate between purines and pyrimidines?

Answer 28

Purines are larger, with 6 carbon ring fused to a five carbon ring, as opposed to a single six carbon ring

Question 29

What sugar is found in RNA?

Answer 29

Ribose

Question 30

What sugar is found in DNA?

Answer 30

Deoxyribose

Question 31

What is the difference between the sugar in DNA and RNA?

Answer 31

presence and absence of oxygen

Question 32

Which carbon is the phosphate group added to in the sugar of a nucleotide?

Answer 32

5' carbon

Question 33

How are adjacent nucleotides joined?

Answer 33

Phosophodiester linkage

Question 34

What is a phosphodiester bond?

Answer 34

Phosphate group that links sugars of two nucleotides, one has a phosphate attached to the 5' carbon, the other has a hydroxyl group on a 3' carbon

Question 35

What specifies the sequence of a gene?

Answer 35

linear order of bases on a chromosome

Question 36

How is cellular DNA structured

Answer 36

Two polynucleotide chains, two sugar phosphate backbones run in antiparallel directions in a double helix, joined together by hydrogen bonds between bases

Question 37

What is the semi conservative model of replication?

Answer 37

New DNA molecule contains one parent strand and one daughter strand

Question 38

What is a nucleoside triphosphate?

Answer 38

A molecule with three phosphate groups

Question 39

Which end are nucleotides added to?

Answer 39

3' end

Question 40

Where does replication begin?

Answer 40

Origin of replication