1.10. Nucleic acids

Question 1

monomers of nucleic acids

Answer 1

nucleotides

Question 2

nucleotide =

Answer 2

pentose sugar (deoxyribose for DNA, ribose for RNA) + PO4^3- + nitrogenous base (N-base)

Question 3

different nitrogenous bases

Answer 3

• Adenine (A), Guanine (G), Cytosine (C), and Thymine (T) (in DNA) or Uracil (U) (in RNA)

Question 4

___ and ___ are made out of two rings and called….

Answer 4

Adenine, Guanine, purines

Question 5

___, ___ and ___ are made our of only one ring and are called….

Answer 5

Cytosine, Thymine, Uracil, pyrimidine

Question 6

which nitrogenous bases are complementary

Answer 6

A-T and G-C

Question 7

nucleotide in DNA with Adenine as a nitrogenous base is called:

Answer 7

deoxyriboadenosine or can be called just Adenine (A)

Question 8

nucleotide in DNA with Guanine as a nitrogenous base is called:

Answer 8

deoxyriboguanosine or can be called just Guanine (G)

Question 9

nucleotide in DNA with Cytosine as a nitrogenous base is called:

Answer 9

deoxyribocytosine or can be called just Cytosine (C)

Question 10

nucleotide in DNA with Thymine as a nitrogenous base is called:

Answer 10

deoxyribotimosine or can be called just Thymine (T)

Question 11

In a dehydration reaction of several nucleotides, a ____ is formed.

Answer 11

polynucleotide chain/strand (RNA)

Question 12

bond connecting two nucleotides

Answer 12

phosphodiester bond

Question 13

Why are nucleotides (polynucleotide chain, deoxyribonucleotide…) called that?

Answer 13

Because they can be found inside of the cell nucleus (but also in cytoplasm)

Question 14

On what does the charge of the PO4^3- depend and how?

Answer 14

on the pH of the environment, if pH<7 then there is an excess in H+ ions that’ll bond with the O- parts of the group - OH subgroup formed (one end of the phosphodiester bond)

Question 15

Where can phospodiester bond be found?

Answer 15

Between neighboring nucleotides in a polynucleotide chain, and between glycerol and fatty acids in a triglyceride molecule.

Question 16

A-T are bonded by __ ___, and G-C with __ ___.

Answer 16

2, hydrogen bonds, 3, hydrogen bonds

Question 17

two strands in a DNA are ___, which means that…

Answer 17

antiparallel, parallel but run in opposite directions

Question 18

draw a non-simplified and a simplified DNA diagram (plus the most simple one - interested only in N-base sequence)

Answer 18

…

Question 19

Which parts make up the backbone of a polynucleotide strand?

Answer 19

alternating sugars (pentose) and PO4^3- groups

Question 20

rule of complementary base pairing

Answer 20

the 2 strands are complementary

Question 21

why can polynucleotide polymerization only happen in the 5’ (five prime end) to 3’ (three prime end) direction?

Answer 21

because of a limitation of the DNA polymizer - its high specificity - can only find pair for and bond the 3 prime end

Question 22

Two DNA strands are coiled around each other in a structure called…

Answer 22

…double helix.

Question 23

What does the N-base/nucleotide sequence determine?

Answer 23

heredity (gives DNA its specificity) and the sequence of amino acids in a polypeptide chain and therefore the structure and function of a protein (the presence or absence of a certain functional protein is a heritable trait).

Question 24

3 different types of RNA

Answer 24

mRNA (messenger), tRNA (transport), rRNA (ribosomal)

Question 25

RNA (ribonucleic acid)

Answer 25

• single-stranded
• Uracil instead of Thymine
• ribose instead of deoxyribose

Question 26

which experiment found evidence that DNA not proteins carry genes?

Answer 26

Hershey-Chase experiment (1952)

Question 27

describe the Hershey-Chase experiment

Answer 27

T2 virus (phage) infected E. coli (bacteria) cell and reprograms it into a phage-producing factory - protein or DNA (only made out of them) - protein has S, DNA has P - two groups - 1st radioactive S in protein coat of phage, 2nd radioactive P in DNA - mixer, centrifuge separating, supernatant (phage), pellet (bacteria) - 2nd: radioactive pellet - bacteria made radioactive by radioactive DNA

Question 28

why was it hypothesized that proteins store genes?

Answer 28

they have a greater capacity for variation (20^n a-a) - nucleotides: 4^n - DNA can be any length (adding to he potential diversity of sequences)

Question 29

what is 4^n?

Answer 29

the number of different DNA sequences made out of n number of bases - DNA has unlimited length

Question 30

If the A:G/C:T ratio is not 1:1…

Answer 30

…a gene mutation is present.

Question 31

pellet

Answer 31

also called a precipitate - made out of the more dense material in the mixture that gets separated by centrifuge

Question 32

supernatant

Answer 32

the less dense part of the mixture