P1252109253IJxYS

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http//members.aol.com/wayneheim/dna-w.jpg
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Key Points
1) Double Helix2) Sugar-phosphate backbone3)
Nucleotide Rungs 4) Hydrogen bonds
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DNA Nucleotides
Adenine
Cytosine
Guanine
Thymine
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ComplementaryBase Pairing DNA
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RNA Ribonucleic Acid
1) Single stranded (usually)
2) Nucleotide Uracil replaces Thymine
3) Three species (for this course)
3.1) messenger RNA (mRNA) 3.2) ribosomal RNA
(rRNA) 3.3) transfer RNA (tRNA)
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ComplementaryBase Pairing RNA
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DNA Packaging
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http//users.ntua.gr/sofial/DNA.jpg
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Terms
Amino acid basic building block of polypeptide
chains.
Polypeptide chain series of linked amino acids.
AKA peptide
chain.
Protein one or more polypeptide chains,
folded and taking on a 3 dimensional
configuration.
Enzyme a type of protein that speeds up
chemical reactions.
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Genetic Code (mRNA)
1) Triplet2) Redundant3) Universal
http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookPROTSYn.html
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Five Steps in ProteinSynthesis (PETAP)
1) Photocopying
2) Editing
3) Transportation
4) Assembly
5) Packaging
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Five Steps in ProteinSynthesis (PETAP)
Common Sense Terms
Scientificese
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I. Photocopying (Transcription)
Definition An RNA strand is synthesized from the
DNA using complementary base pairing.
Process
1) Transcription stuff binds to a promoter
region of the DNA.
2) An enzyme slices the DNA, making it single
stranded.
3) Another enzyme (polymerase) synthesizes a
strand of RNA using one of the DNA strands as
a template.
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II. Editing(Post-transcriptional modification)
Definition Nonmessage segments in the newly
synthesized RNAstrand are edited out.
Process
1) Enzymes excise the introns (nonmessage
segments) from the RNA strand.
2) Other enzymes splice together the exons
(message segments) giving messenger RNA
(mRNA).
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III. Transportation (Transportation)
Definition mRNA is transported from the nucleus
to the cytoplasmand attaches to a ribosome.
Process
(same as the definition)
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IV. Assembly (Translation)
Definition The mRNA codons are read and the
corresponding aminoacid is added to the
polypeptide chain.
Process
1) A codon enters the reading frame of a
ribosome.
2) A transfer RNA (tRNA) molecule with the
complementary anticodon binds to the codon of
mRNA.
3) The amino acid carried by the tRNA molecule is
added to the polypeptide chain.
3) Steps 1 to 3 are repeated until all codons are
read.
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Transfer RNA(schematic)
anticodon
bar code
other RNA
Trp
amino acid
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http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookPROTSYn.html
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http//tidepool.st.usm.edu/pix/protsynth.gif
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Open window (A) and fly kite (B).  String (C)
lifts small door (D) allowing moths (E) to escape
and eat red flannel shirt (F).As weight of shirt
becomes less, shoe (G) steps on switch (H) which
heats electric iron (I) and burns hole in pants
(J).Smoke (K) enters hole in tree (L), smoking
out opossum (M) which jumps into basket (N),
pulling rope (O) and lifting cage (P),allowing
woodpecker (Q) to chew wood from pencil (R),
exposing lead.Emergency knife (S) is always
handy in case opossum or the woodpecker gets sick
and can't work.
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The Self-Operating Napkin As you raise spoon of
soup (A) to your mouth it pulls string (B),
thereby jerking ladle (C) which throws cracker
(D) past parrot (E). Parrot jumps after cracker
and perch (F) tilts, upsetting seeds (G) into
pail (H). Extra weight in pail pulls cord (I),
which opens and lights automatic cigar lighter
(J), setting off sky-rocket (K) which causes
sickle (L) to cut string (M) and allow pendulum
with attached napkin to swing back and forth
thereby wiping off your chin.