Nucleotides & Nucleic Acids

Question 1

what is a nucleotide made up from ?

Answer 1

• pentose sugar
• nitrogenous base
• phosphate group

Question 2

name of DNA

Answer 2

deoxyribonucleic acid

Question 3

name of RNA

Answer 3

ribonucleic acid

Question 4

(simple) function of DNA

Answer 4

store genetic information

Question 5

(simple) function of RNA

Answer 5

make proteins from the instructions in DNA

Question 6

what is the function of a nucleotide ?

Answer 6

They are monomers that make up nucleic acids (e.g. DNA / RNA)

Question 7

what is the sugar in DNA?

Answer 7

deoxyribose

Question 8

name the 4 bases in DNA

Answer 8

Adenine, thymine, guanine and cytosine

Question 9

name the 4 bases in RNA

Answer 9

Adenine, uracil, guanine and cytosine

Question 10

what does DNA stand for ?

Answer 10

deoxyribonucleic acid

Question 11

what type of bases are adenine and guanine ?

Answer 11

purine

Question 12

what type of bases are cytosine and thymine (uracil) ?

Answer 12

pyrimidine

Question 13

name the two bonds in a nucleotide

Answer 13

ester bond and glycosidic bond

Question 14

what reactions occur to make the bonds in a nucleotide

Answer 14

condensation reactions (2)

Question 15

where is the link between nucleotides from and to?

Answer 15

phosphate and pentose group

Question 16

Describe a purine base

Answer 16

two carbon-nitrogen rings joined together

Question 17

Describe a pyrimidine base

Answer 17

one carbon-nitrogen ring

Question 18

what does RNA stand for ?

Answer 18

ribonucleic acid

Question 19

which sugar does RNA contain?

Answer 19

ribose sugar

Question 20

what sugar does DNA contain ?

Answer 20

deoxyribose sugar

Question 21

what type of nucleotide is ADP/ATP?

Answer 21

phosphorylated nucleotide

Question 22

how do you phosphorylate a molecule?

Answer 22

add one or more phosphate group to it

Question 23

what does ADP stand for ?

Answer 23

adenosine diphosphate

Question 24

what does ATP stand for ?

Answer 24

adenosine triphosphate

Question 25

what does ADP contain ?

Answer 25

adenine, sugar ribose, 2 phosphate groups

Question 26

what does ATP contain ?

Answer 26

adenine, sugar ribose, 3 phosphate groups

Question 27

function of ATP ?

Answer 27

provides energy for chemical reactions in a cell

Question 28

how is ATP synthesized ?

Answer 28

ADP + Pi (inorganic phosphate) using energy from respiration

Question 29

how is energy stored / released with ATP ?

Answer 29

stored in phosphate bond, which is broken to form ADP and Pi (energy is released)

Question 30

what is the link between nucleotide molecules called ?

Answer 30

phosphodiester bond

Question 31

what is sugar-phosphate backbone ?

Answer 31

chain of sugars and phosphates in polynucleotides

Question 32

describe a phosphodiester bond

Answer 32

phosphate group and two ester bonds

Question 33

what are excess purines broken down to ?

Answer 33

uric acid (in the liver)

Question 34

how is uric acid harmful ?

Answer 34

is insoluble and forms crystals in joints if there is too much in the blood

Question 35

How is a double helix formed ?

Answer 35

two DNA polynucleotide strands join together between bases (anti parallel) and twist

Question 36

what type of bonding is between bases ?

Answer 36

Hydrogen bonding

Question 37

how many bonds between G - C

Answer 37

3 bonds

Question 38

how many bonds between A -T

Answer 38

2 bonds

Question 39

what word to use when talking about bases

Answer 39

complementary base pairing

Question 40

Describe DNA purification experiment

Answer 40

1. break up cells 2. make solution of detergent, salt and distilled water 3. add 1 and 2 together in water bath at 60'C for 15 mins 4. cool in ice bath, filter into new tube 5. add protease enzymes 6. slowly add cold ethanol down side of tube 7. DNA will form white suspension

Question 41

why is salt needed in DNA purification experiment

Answer 41

binds to DNA and causes it to clump together

Question 42

why is detergent needed in DNA purification experiment

Answer 42

breaks down cell membrane

Question 43

why is high temp needed for DNA purification experiment

Answer 43

should stop enzymes in cells from working properly and breaking down the DNA

Question 44

what is the function of DNA helicase ?

Answer 44

breaks the hydrogen bonds between two polynucleotide DNA strands (unzipping the helix) during DNA replication

Question 45

during DNA replication, what happens once helix is unzipped ?

Answer 45

- free floating DNA nucleotides join to exposed bases on each template strand - new strand nucleotides join, sugar phosphate backbone formed, H-bonds form, strands twist (double helix)

Question 46

what joins the new strand nucleotides in DNA replication

Answer 46

DNA polymerase

Question 47

what type of copying is DNA replication ?

Answer 47

semi - conservative replication ( 1 new strand, 1 original strand )

Question 48

what happens if DNA base sequence is changed ?

Answer 48

mutation occurs

Question 49

what is a gene ?

Answer 49

sequence of DNA nucleotides that codes for a polypeptide

Question 50

what determines the order of amino acids ?

Answer 50

order of nucleotide bases in a gene

Question 51

which is the longer molecule ... DNA or RNA ?

Answer 51

DNA

Question 52

what is the difference in helix between DNA and RNA ?

Answer 52

DNA - double helix | RNA - single helix

Question 53

what codes for 1 amino acid ?

Answer 53

1 codon, which is made up from 3 nucleotide bases

Question 54

where is DNA located ?

Answer 54

only the nucleus

Question 55

why can DNA not move out of the nucleus ?

Answer 55

too large

Question 56

what is transcription ?

Answer 56

copying section of DNA into mRNA

Question 57

what is translation ?

Answer 57

mRNA joins with a ribosome, where it is used to synthesize a protein

Question 58

Describe messenger RNA (mRNA)

Answer 58

- made in nucleus - three adjacent bases (codon) - carries genetic code from DNA in nucleus to ribosome

Question 59

Describe transfer RNA (tRNA)

Answer 59

- in cytoplasm - has amino acid binding site one end, anticodon on other end - carries amino acids to ribosomes during translation

Question 60

Describe ribosomal RNA (rRNA)

Answer 60

- forms 2 sub units in a ribosome | - helps catalyse formation of peptide bonds between amino acids

Question 61

what three things is genetic code described as ?

Answer 61

non - overlapping / degenerate / universal

Question 62

what does it mean that genetic code is non - overlapping ?

Answer 62

each base triplet is read in sequence

Question 63

what does it mean that genetic code is degenerate ?

Answer 63

- more possible combinations of triplets than amino acids so... - some used for start / stop - some amino acids have several combinations

Question 64

what does it mean that genetic code is universal ?

Answer 64

same base triplet codes for same amino acid for all living organisms

Question 65

outline process of transcription

Answer 65

1. RNA pol attaches to DNA and breaks H bonds 2. RNA pol lines up free nucleotides w/ compl base pair 3. RNA pol moves along DNA, separating strands, assembling mRNA strand 4. H bonds of DNA reform once RNA pol passes 5. stop codon reaches, detaches, mRNA moves out of nucleus

Question 66

outline process of translation

Answer 66

1. mRNA attaches to ribosome, tRNA carries aas 2. tRNA w/ anticodon compl to start codon of mRNA attaches 3. 2nd tRNA attaches ... 4. rRNA catalyses formation of peptide bonds 5. continues until stop codon, polypeptide chain moves away