dna basics. organisms are made up of cells the nucleus of the cell contains dna
TRANSCRIPT
DNA Basics
Organisms are made up of cells
The nucleus of the cell contains DNA
3’C
5’ end
5’C
3’C
5’C
3’ endOH
Figure 5.26
O
O
O
O
Nitrogenousbase
Nucleoside
O
O
O
O P CH2
5’C
3’CPhosphate
group Pentosesugar
(b) NucleotideFigure 5.26
O
DNA is a linear polymer made up of repeating units
DNA is very stable; the data is backed up.
DNA is a double helix
But start to get used to thinking about DNA sequence like this...
1 ctcctagtcc agacgccatg ggtcatttca cagaggagga caaggctact atcacaagcc 61 tgtggggcaa ggtgaatgtg gaagatgctg gaggagaaac cctgggaagg ctcctggttg 121 tctacccatg gacccagagg ttctttgaca gctttggcaa cctgtcctct gcctctgcca 181 tcatgggcaa ccccaaagtc aaggcacatg gcaagaaggt gctgacttcc ttgggagatg 241 ccataaagca cctggatgat ctcaagggca cctttgccca gctgagtgaa ctgcactgtg 301 acaagctgca tgtggatcct gagaacttca agctcctggg aaatgtgctg gtgaccgttt 361 tggcaatcca tttcggcaaa gaattcaccc ctgaggtgca ggcttcctgg cagaagatgg 421 tgactggagt ggccagtgcc ctgtcctcca gataccactg agctcgctgc ccatgatgca 481 gagcttcaag gataggcttt attctgcaag caatacaaat aataaatcta ttctgctaag 541 agatc
DNA sequence
Genetic Basics
Central Dogma
The DNA double helix unzips
Transcription:
A messenger RNA (mRNA) copy of the gene is made
RNA has ribose instead of deoxyribose, has uracil instead of thymine, and is single stranded.
DNA RNA protein: information flow
Translation:
The messenger RNA copy of the gene is “cranked” through a ribosome.
The codons of the mRNA are read as a template to make a protein.
DNA RNA protein: information flow
Translation by Codon
• The linear DNA code is read in sets of 3 bases, called codons.
• AUG is the start codon.
• UAA, UAG and UGA are “stop” codons.
• The code is redundant; more than one codon encodes the same protein.
We will talk about proteins like this...
1 mshtasscqe lvencavhva gmaqedsrrg qvpssfyhga nqeldlstkv ykresgspys 61 vlvdtkmskp hlheteeqpy fretravsdv havkedrens ddteeeeeev sykreqiive 121 vnlnnqtlnv skgekgvssq sketpvlkts seeeeeesee eatddsndyg enekqkkkek 181 iv
The previous DNA sequence had 546 nucelotides.
How many proteins should be in this sequence?
Protein Sequence
Protein strings fold into 3D structures
Lysozyme protein– 2 models
Figure 8.16
Substate
Active site
Enzyme
(a)
Hexokinase protein modifying a glucose molecule in its active site
3D proteins do the cell’s work
Figure 8.16 (b)
Enzyme- substratecomplex