Nucleic Acids

Question 1

What is ATP made up of?

Answer 1

Adenine
Ribose
3 phosphates

Question 2

What does ATP stand for?

Answer 2

Adenosine triphosphate

Question 3

Why is ATP known as the universal energy currency of the cell?

Answer 3

Used as a source of energy in all cells in all organisms
Active transport of molecules across membranes
Transport molecules within a cell

Question 4

What does ADP stand for?

Answer 4

Adenosine diphosphate

Question 5

How does ATP become ADP?

Answer 5

ATP is hydrolysed by ATPase

Question 6

How does ADP become ATP?

Answer 6

By phosphorylation
Condensation reaction by ATP synthase

Question 7

How much energy is released when ATP is hydrolysed into ADP?

Answer 7

30.6 kJ/mol ATP

Question 8

What type of reaction is it when ATP is hydrolysed into ADP?

Answer 8

Exergonic (catabolic)

Question 9

What type of reaction is it when ADP is combined with Pi into ATP?

Answer 9

Endergonic (anabolic)

Question 10

Why is ATP a good energy currency?

Answer 10

Energy in small amounts, when and where needed
Single step reaction so energy is released immediately
Only requires one enzyme - ATPase

Question 11

What are the seven roles of ATP

Answer 11

Active transport
Metabolic processes
Nerve transmission
Secretion
Protein synthesis
Cellular division
Muscle contraction

Question 12

What are the sub units of DNA called?

Answer 12

Nucleotides

Question 13

What is DNA made up of?

Answer 13

Deoxyribose sugar
Phosphate group
Nitrogenous base

Question 14

What are the nitrogenous bases in DNA?

Answer 14

Cytosine
Guanine
Thymine
Adenine

Question 15

What are the nitrogenous bases in RNA?

Answer 15

Cytosine
Uracil
Guanine
Adenine

Question 16

What are pyrimidines?

Answer 16

Single ring structure nitrogenous bases

Question 17

Why are purines?

Answer 17

Double ring structure nitrogenous bases

Question 18

Which nitrogenous bases are pyrimidines?

Answer 18

Cytosine
Thymine
Uracil

Question 19

Which nitrogenous bases are purines?

Answer 19

Adenine
Guanine

Question 20

What is the backbone of DNA made up of?

Answer 20

Deoxyribose and phosphate

Question 21

What are the bonds that hold together the backbone of DNA?

Answer 21

Phosphodiesta bonds

Question 22

What is the structure of messenger RNA (mRNA)?

Answer 22

Long single stranded helix

Question 23

What is the function of mRNA?

Answer 23

Manufactured in nucleus and carries genetic code from DNA in the nucleus to the ribosome

Question 24

What is the structure of ribosomal RNA (rRNA)?

Answer 24

Long, large, complex molecule, both double and single helixes

Question 25

What is the function of rRNA?

Answer 25

Ribosomes are made up of protein and rRNA

Question 26

What is the structure of transfer RNA (tRNA)?

Answer 26

Small, single-stranded clover leaf shape. Amino acids attach at one end. Anticodon of 3 based on the other end

Question 27

What is the function of tRNA?

Answer 27

Bring amino acids to ribosomes so proteins can be synthesized

Question 28

What are the differences between a DNA nucleotide with an RNA nucleotide?

Answer 28

DNA: deoxyribose, A C T G bases RNA: ribose, A C U G bases

Question 29

What are the differences between a DNA polymer and an RNA polymer?

Answer 29

DNA polymer: double stranded, only 1 type, stays in nucleus (in eukaryotes) RNA polymer: single stranded, 3 types (mRNA, rRNA, tRNA), made in nucleus, leaves and then goes into cytoplasm

Question 30

Which enzyme unwinds and separates the base pairs in the double helix?

Answer 30

DNA helicase

Question 31

Which enzyme links the nucleotides covalently allowing H bonds to form?

Answer 31

DNA polymerase

Question 32

What is the correct term for the replica DNA helix?

Answer 32

Semi-conservative replication (one new strand, and one old strand)

Question 33

What is the function of DNA ligase?

Answer 33

To join together fragments of newly synthesized DNA to form a seamless strand

Question 34

What is the function of DNA primase?

Answer 34

Synthesizes short RNA primers that are essential for initiating DNA replication

Question 35

What is the difference between the lagging and leading strands in DNA replication?

Answer 35

The lagging strand is put together discontinuously, using Okazaki fragments The leading strand is put together continuously

Question 36

Which bonds hold together the sugar-phosphate backbone of DNA?

Answer 36

Phosphodiester bonds

Question 37

What was the goal of Meselson and Stahl's experiment?

Answer 37

To prove that DNA was semi-conservative

Question 38

How did Meselson and Stahl carry out the first stage of their experiment?

Answer 38

Cultured E.coli in a medium containing amino acids with the heavy isotope 15N The 15N was incorporated into the DNA of the E.coli Bacterial DNA was extracted via lysis (breaking open the cells) and put into an ultra centrifuge Banding in the test tube was observed

Question 39

How did Meselson and Stahl carry out the second stage of their experiment?

Answer 39

The 15N bacteria were washed and transferred to a medium containing 14N and divided once (one generation) DNA was extracted via lysis and put into an ultra centrifuge Banding in the test tube was observed

Question 40

How did Meselson and Stahl carry out the third stage of their experiment?

Answer 40

The bacteria were allowed to replicate again (2nd generation) DNA extracted via lysis and put into an ultra centrifuge Banding in the test tube was observed

Question 41

How does transcription happen in protein synthesis?

Answer 41

DNA copied into a complementary strand of mRNA Gene to be transcribed unzips and the H bonds break Activated RNA nucleotides bind (H bonds) to their exposed complementary base - catalysed by DNA polymerase Produces a copy of the coding strand in mRNA form mRNA released from DNA and passes through the nuclear envelope

Question 42

What happens during translation?

Answer 42

mRNA binds to small subunit of ribosome tRNA binds to large subunit of ribosome Peptide bonds form between the amino acids on the anticodon Form a polypeptide chain

Question 43

What is the structure of a ribosome?

Answer 43

Made up of a large subunit and a small subunit Large subunit contains an amino acid binding site, a peptidyl-tRNA binding site and an exit site

Question 44

What are exons?

Answer 44

Regions of DNA that code for proteins

Question 45

What are introns?

Answer 45

Regions of noncoding DNA inbetween exons

Question 46

What happens during RNA splicing?

Answer 46

Ribozymes used to remove the introns and splice together the exon-derived RNA into mRNA

Question 47

What are STR's?

Answer 47

Short tandem repeats - length of the STR (how many repeats) e.g. GATAGATAGATA has 3 repeats- inherited from parents.

Question 48

When are STR's used?

Answer 48

In genetic fingerprinting in order to show differences between individuals

Question 49

What are three main mutation types?

Answer 49

Deletion Insertion Substitution

Question 50

Which mutations cause a frameshift in the amino acid sequence?

Answer 50

Deletion Insertion

Question 51

What are the different types of a substitution mutation?

Answer 51

Missense Silent Nonsense

Question 52

What is a missense mutation?

Answer 52

If the substitution changes the amino acid

Question 53

What is a silent mutation?

Answer 53

If the substitution does not change the amino acid

Question 54

What is a nonsense mutation?

Answer 54

If the amino acid is changed to a stop

Question 55

What is the one gene one polypeptide hypothesis?

Answer 55

Every gene synthesises for one polypeptide