DNA

Question 1

Nucleic acids are

Answer 1

Large molecules contained in the nucleus that are important for transferring and storing genetic info

Question 2

2 types of nucleic acids

Answer 2

DNA-deoxyribonucleic acid

RNA-Ribonucleic acid

Question 3

Elements in nucleic acids

Answer 3

C H O N P

Question 4

Nucleotides

Answer 4

Monomers
With a phosphate group,pentose backbone(deoxi or rib) and a base pair

Question 5

Nucleotides bonding

Answer 5

Condensation reaction
Phosphodiester

Question 6

Who discovered the structure of DNA

Answer 6

James Watson and Francis Crick

Question 7

What is dna composed of

Answer 7

2 polynucleotide strands that are antiparallel

Question 8

Adenine and thymine H bonds

Answer 8

2

Question 9

Guanine + cytosine H bonds

Answer 9

3

Question 10

Why does DNA with a higher GC content have a higher mp

Answer 10

More H bonds to break

Question 11

How is DNAs structure related to its function

Answer 11

-Sugar phosphate backbone gives it strength
-Helical coiled shape=compact
-sequence of bases codes for amino acids
-long molecule=stores large amount of genetic info
-H bonds daily broke for replication and transcription
-Double helix protects bonds
-stable preventing code being corrupted

Question 12

What is complementary to DNA polymerase 3’ or 5’

Answer 12

3’

Question 13

Dna helicase

Answer 13

Breaks H bonds between base pairs

Question 14

Polymerase

Answer 14

Adjacent nucleotides
Forms phosphodiester bonds between phosphate and deoxyribose

Question 15

How is dna replicated

Answer 15

-helicase breaks h bonds between nucleotides
-both strands are used as templates
-free nucleotides are attracted to their complementary base
-polymerase makes phosphodiester bonds between the phosphate and deoxyribose
-2 new strands are made of half the original dna

Question 16

2 models for dna replication

Answer 16

Conservative
Semi conservative

Question 17

Conservative hypothesis

Answer 17

1 new DNA molecule made entirely of new material while the other was entirely old material

Question 18

What is an ion

Answer 18

An element that has a different number of electrons than it would originally have and has a charge

Question 19

Fe2+

Answer 19

Haemoglobin
Help bind to oxygen

Question 20

Nitrate ions

Answer 20

Amino acids
Dna

Question 21

Phosphate ions

Answer 21

Activate enzymes
So they can hydrolyse

Produce phospholipid

Affect osmosis

Question 22

Sodium ions

Answer 22

Are involved in sodium potassium pump in the co transport of glucose

Aid nerve impulses

Is moved by active transport creating diffusion gradient which affects water potential

Question 23

Ca2+

Answer 23

Nerve impulses
Muscle contracting
Synapses

Question 24

H+

Answer 24

Générâtes ATP

Question 25

• Which scientists came up with a method to test for DNA replication? Date?

Answer 25

Meselsohn and Stahl (1958)

Question 26

• They (m+s)used an isotope of which element in their experiment? Can you name them?

Answer 26

14N (light nitrogen) & 15N (heavy nitrogen)

Question 27

• Which organism did they(m+ s) use in their experiment?

Answer 27

E.Coli bacteria

Question 28

• Why did they(m and s) use bacteria?

Answer 28

Bacteria will take in nitrogen from their surroundings into any new DNA they make!

Question 29

Name the 4 bases found in RNA

Answer 29

Adenine, Uracil, Guanine & Cytosine

Question 30

Which sugar is found in RNA? What does RNA stand for?

Answer 30

ribose Ribonucleic acid

Question 31

Is RNA double or single stranded? Name 3 different types of RNA

Answer 31

single tRNA, mRNA, rRNA

Question 32

tRNA location and function

Answer 32

cytoplasm, carries amino acids to ribosomes for protein synthesis

Question 33

rRNA location and function

Answer 33

produced in nucleolus found in ribosomes

Question 34

mRNA location and function

Answer 34

leaves nucleus and goes to ribosomes – protein synthesis

Question 35

Eukaryotic chromosome structure

Answer 35

• ChromosomeslongpiecesofDNAfoundinthe nucleus. • Chromosomesareonlyvisiblewhenthecellsare dividing (from prophase onwards). • DNAiswrappedaroundhistoneproteinsforming nucleosomes – these coil up further to form chromatin. • Thesenucleosomesthencoiluptightlyduringmitosis (and meiosis). •Telomeres at the end of the chromosomes are repetitive DNA – they offer protection against degradation.