Nucleic Acids

Question 1

Degenerate

Answer 1

If amino acids have more than one triplet that codes for it.

Question 2

Universal

Answer 2

The same four bases used in all organisms.

Question 3

Mutations

Answer 3

When bases are deleted or changed. This can change the overall protien created.

Question 4

mRNA

Answer 4

Attatches onto template strand of DNA. Uses Uracil instead of thymine.

Question 5

tRNA

Answer 5

Transfer RNA. It has an anticodon that attatches to each triplet on an mRNA. The tRNA also carries an amino acid. This amino acid is specific to the codon that attatches to the anticodon.

Question 6

3 componants of a nucleotide in DNA

Answer 6

• nitrogenous base, ATCG
• sugar deoxyribose
• a phosphate group

Question 7

Purines

Answer 7

• double carbon ring structure
• Adenine
• guanine

Question 8

Pyrimidines

Answer 8

• single carbon ring structure
• cytosine
• thymine

Question 9

5’ end. 3’ end.

Answer 9

If the 5th carbon in wach deoxyribose is pointing up, it’s the five end. If the 3rd carbon is pointing up, it’s the three end.

Question 10

Structure of RNA

Answer 10

• ribose sugar
• nitrogenous base (GCAU)
• a phosphate

Question 11

ATP structure

Answer 11

• Adenine nitrogenous base
• 3 phosphates
• ribose sugar

Question 12

What bond links nucleotides together?

Answer 12

Phosphodiester bond

Question 13

Introns and exons

Answer 13

The parts of pre mRNA. Exons are kept, introns are SPLICED. HA HA

Question 14

Process of removing introns?

Answer 14

Splicing

Question 15

What is the mRNA called before spilcing?

Answer 15

pre-mRNA

Question 16

what is mRNA called after SPLICING?

Answer 16

mature mRNA

Question 17

what is a nucleosome?

Answer 17

A bunch of histons wrapped in DNA.

Question 18

What do nucleosomes create?

Answer 18

They coil to create chromatin. chromatin makes up chromosomes.

Question 19

How does atp release energy?

Answer 19

A small amount of energy is required to break the bind holding the last phosphate group.
A large amount of energy is released when the liberated phosphate group undergoes reactions involving bond formation.

Question 20

Properties of ATP (5)

Answer 20

• small
• water soluble (energy requiring processes happen in aqueous environments)
• large enough to be useful in cellular reactions but not so large that energy is wated as thermal energy.
• releases energy in small quantities
• easily regenerated.

Question 21

3 main types of activity in cells…

Answer 21

• synthesis
• transport
• movement

Question 22

what is phosphorylation

Answer 22

the reattaching of a phosphate molecule to a molecule of ADP, releasing a water molecule. this is, therefore, a condensation reaction

Question 23

ATP is un..

Answer 23

unstable

Question 24

What happens at the beginning of translation…

Answer 24

The mRNA binds to the small subunit of the ribosome at its start codon.

Question 25

Ribosome structure

Answer 25

Two subunits, one large and one small, each made up of equal amounts of protein.

Question 26

Two roles of the rRNA

Answer 26

- maintains stability of the protein synthesis sequence. - biochemical tole in catalysing the reaction

Question 27

What is the 5' 3' strand called???

Answer 27

the sense strand

Question 28

What is the 3' 5' end called???

Answer 28

the antisense strand

Question 29

Which strand acts as the template strand???

Answer 29

the antisense strand

Question 30

The sense strand is also the...

Answer 30

coding strand

Question 31

4 bases, how many different codons can there be?

Answer 31

64 codons (combinations of the 4 bases)

Question 32

how many start codons are there?

Answer 32

1 (ATG)

Question 33

function of introns

Answer 33

seperating genes

Question 34

how many bases can fit in the ribosome at a time (translation)?

Answer 34

6

Question 35

how is the amino acid bound to the tRNA molecule?

Answer 35

using ATP

Question 36

why do we call strands 5" 3"?

Answer 36

if the 5th carbon is pointing upwards

Question 37

Which carbons form covelant bonds in phosphodiester linkage?

Answer 37

3 rd and 5 th

Question 38

What can hydrolysis of ATP be used for?

Answer 38

- releasing inorganic phosphate to phosphorylate other compounds - coupling to other reactions that need energy

Question 39

what is the name of the enzyme that resynthesises ATP during photosynthesis and respiration?

Answer 39

ATP synthase

Question 40

differences in structure between tRNA and DNA?

Answer 40

- mRNA has more nucleotides - mRNA is straight tRNA is folded - mRNA has no paired bases

Question 41

what does a stop codon code for?

Answer 41

nothing / no amino acid