Nucleic acids

Question 1

What did Pythagorus conclude about DNA?

Answer 1

Semen from father passed hereditary information to mother during intercourse. Semen collected “mystical vapors from man”

Question 2

What did Plato conclude about DNA?

Answer 2

By using pythagorus’ theorum of human development, Plato stated perfect children derived from perfect parents

Question 3

What did Aristotle conclude about DNA?

Answer 3

The feutus is formed from contributions from mother and father

Question 4

What did Paracelsus conclude about DNA?

Answer 4

Believed the father transferred a humonculus to the mother. Father had total control of offspring - mimicked religious beliefs

Question 5

Describe Darwin’s role in DNA history

Answer 5

Published origin of Species in 1859 - it avoided the topic of human DNA inheritance to avoid religious controversy.

Question 6

Describe Mendel’s role in DNA history

Answer 6

Mendel was a failing science and maths teacher.
1864 - He crossed tall peas with short peas = an hybrid pea was created that was NOT intermediate.
Mendel determined hybrid pea resembled one of the parents - created terms dominant and recessive

Question 7

What did Hugo De Vries conclude about DNA?

Answer 7

Every human trait was governed by a single particle of evidence, one from the sperm and one from the egg (DNA) - he used Mendel’s evidence to conclude this. A single DNA particle was called “Pangenes” by De Vries.

Question 8

What is the relationship between the size of the genome and the number of coding genes (exons)?

Answer 8

No relationship between genome size and number of exons

Question 9

What different segments can be found in DNA? What are their roles?

Answer 9

Exons - coding regions carrying the code for a particular protein.
Introns - non-coding regions that play a role in gene expression and regulation.

Question 10

What is meant by spermism?

Answer 10

Spermism - over time semen collects a library of the man which is passed on during intercourse. Helps explain Pythagorus’ theory of development

Question 11

What did Wolff conclude about DNA?

Answer 11

Vis essntialis corporis - sperm and egg provided information to the uterus

Question 12

What percentage of protein coding exons can be found in the human genome?

Answer 12

1.5% of the human genome is protein coding

Question 13

Describe the structural components of DNA

Answer 13

Deoxyribose sugar (5C) - not oxygentated
Phosphate group - linked to sugar of next nucleotide by 3’ to 5’ phospodiester bond
Nitrogenous base - either purine (A or G) or pyrimidine (T or C)

Question 14

Describe the structural components of RNA

Answer 14

Ribose sugar (5C) - oxygenated
Phosphate group
Nitrogenous base - either purine (A or G) or pyrimidine (U or C)

Question 15

Describe the structure of Pyrimidine bases

Answer 15

Cytosine, Thymine and uracil (RNA)
Single heterocyclic aromatic ring
Contain fewer nitrogen atoms

Question 16

Describe the structure of Purine bases

Answer 16

Adenine and Guanine
Double heterocyclic aromatic ring
More nitrogen atoms

Question 17

What is a nucleoside?

Answer 17

Nitrogenous base covalently bound to C1 of sugar

Question 18

List the ribonucelosides

Answer 18

PurINE ribonuclosides = AdenoSINE and GuanoSINE

PrymiDINE ribonucleosides = CytiDINE and UriDINE

Question 19

List the deoxyribonucleosides

Answer 19

Purine deoxyribonucleosides = Deoxyadenosine and Deoxyguanosine
Prymidine deoxyribonucleosides = Deoxycytidine and Thymidine

Question 20

What is a nucleotide?

Answer 20

Nucleoside (base and sugar) + Phosphate group

Question 21

How are nucleotides joined in the backbone?

Answer 21

Phosphodiester bonds - the hydroxyl group of one sugar at C3 is linked to the phosphate group at C5 of another sugar. Phosphodiester bonds run from 3’ to 5’.

Question 22

What is the charge of nucleic acids?

Answer 22

Negatively charged due to many negative phosphate groups

Question 23

How many base pairs are there per turn of the double helix?

Answer 23

10.5 base pairs per turn of the double helix

Question 24

How is the stability of the double helix maintained?

Answer 24

Dipole dipole interactions and hydrophobic interactions maintain the stability of the double helix.

Question 25

Describe DNA base pairing

Answer 25

Purine always pairs with pyrimidine
A and T = 2 H bonds
C and G = 3 H bonds

Question 26

How is DNA arranged within cells?

Answer 26

DNA is wrapped with histone protein and RNA to form chromatin. Chromatin packages DNA into a smaller volume and protects it

Question 27

What is the structure of RNA?

Answer 27

Single strand

Has self-complementary regions of chain which bind together via H bonds = form globular conformations/ a helical shape