A1.2 Nucleic Acids SL HL

3 characteristics of DNA

1. information for creating life in the next generation

2. form of a code, language

3. can change through natural selection

Virus are not ____ but has ___ or ___

Virus are not organisms but has DNA or RNA

DNA and RNA stands for

Deoxyribonucleic Acid,

Ribonucleic Acid

Draw and label 3 components of DNA

label the bonds involved with the C numbered

1. Phosphate [PO₄]^3-

2. Pentose deoxyribose sugar

3. Nitrogenous base

Sugar-phophate backbone with a covalant bond

bases bonded in weak hydrogen bonds

The complementary base pairs are (FULL NAME)

Adenine - Thymine or Uracil (double bond)

Cytosine - Guanine (tripple bond)

Draw the deoxyribose VS ribose structure

DNA differs in ___ and ___ for all organisms

length, sequence

DNA is efficient becuase it is… (length and base paris)

• 2 meters long (human) and 3 billion base pairs.

• very storage efficient.

compare and contrast DNA with RNA (4)

Which are purines and pyrimidines? How do they bond?

Purines: Adenine, guanine

Pyrimidines: Thymine, Uracil, Cytosine

purines and pyrimidines bond in hydrogen bonds (weaker than covalent bonds)

In what two processes are base sequence is critically maintained?

1. Mitosis

2. Gene expression

cbp are critcally maintained by accurately manipulating the active site of cbp

L.U.C.A

Last Universal Common Ancestor

• genetic ancestor fo all domains of life

• discovered by following the genes of trees, plants, fungi

what direction is DNA constructed in?

Attaches 5’ of a DNA nucleotide to the 3’ end of a strand.

Of the 3’ end of the parent strand to the 5’ end.

Why are purines and pyrimidines the only combination?

1. width of 3 rings (2 nm)is just enough for it to be stable

2. it has to be a constant width across the DNA to be stable

Draw the structure of nucleosomes

• octamer of histones in the core

• DNA strand coils around the histones

• H1 linker histone secures the DNA strand, attched in the linker DNA

What do Nucleosomes coil into?

Chromatin Fibre and then to a chromosome

What type of cell are nucleosomes found in?

eukaryotes

Hershey and Chase’s Experiment 1952 (purpose, method and results)

• To discover what the heridetary material was

• radioactive phosphorus labeled on DNA

• radioactive sulfur labeled on protein

1. two samples of bacteriophate with two different labels infects baceria

2. blend the mixture in a blender

3. centrifuge the sample so that:

   bacteriophate at the top (low density)

   bacteria at the bottom (high density)

• Sulfur remained on bacteriophage or extracellular

• Phosphate found in the bacetria

• proved the Avery-Macload-McCarty suspections

Watson and Crick discovery

DNA double helix structure and heridetery in 1953

Radtioisotopes’ definition and use

• Atom with an unstable nucleus that emits radiation as it changes to become more stable

• Trace location and movement of a labelled molecule

• A significant tech. breakthrough

Chargaff’s falsification (method and results)

• Examine base pairs of DNA in various species

• organise them into tables and percentages

• %A=%T

• %C=%G

• Falsified the tetranucleotide theory that A=T=C=G

mRNA is ___ to DNA

mRNA is antisense to DNA