Download DNA RNA and Proteins

Warm Up
• Answer the following questions
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What is DNA? What does D.N.A. stand for?
What does DNA have to do with genes?
What in the media have you heard about DNA?
What is DNA made up of?
DNA, RNA, & Proteins
Test:
3/11(ADAY) and 3/12(BDAY)
DNA
• Gene piece of a chromosome that gives
instructions for inherited traits
• Genes are made of smaller segments called
DNA
• Deoxyribonucleic acid (DNA)
• Very simple molecule, not thought to be
genetic material until 1950
• It took many experiments to determine that
DNA was the genetic material
What lead to discovery?
• 1928: Frederick Griffith bacterial transformation
• 1940: Oswald Avery determined that DNA was the
genetic material being transformed in bacteria
• 1948: Hershey and Chase proved that DNA was the
genetic material and not proteins in viruses
• 1949: Erwin Chargaff base pairing
• 1952: Rosalind Franklin and Maurice Wilkins x-ray
crystallography to prove that DNA is a double helix shape
• 1953: Watson and Crick get credit for discovery of the
structure of DNA
• 1962: Crick, Watson, and Wilkins were all awarded Nobel
Prize for the discovery of the structure of DNA, but Franklin
did not due to her death prior to the award.
Structure of DNA
• Spiraling staircase double
helix
• Two antiparallel or
complementary strands made
up of linked subunits called
nucleotides
• Major Grove and Minor Groove
– Large turn
short turn
Nucleotides
• Each nucleotide is made
up of three parts:
– Phosphate group
backbone
– Five carbon sugar
(deoxyribose sugar)
– Nitrogenous
(nitrogen) base
Phosphate Group and Five Carbon
Sugar
Nitrogenous Bases
• The information in DNA is determined by the
order of these bases, and base pairing allows the
information to be copied in a unique manner
• Four bases:
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Adenine (A)
Guanine (G)
Thymine (T)
Cytosine (C)
Purines
Pyrimadines
• Base Pairing:
– A pairs with T (two hydrogen bonds)
– G pairs with C (three hydrogen bonds)
DNA Replication
• Replication making a duplicate or copy
• Steps:
– Two DNA strands unwind from each other like a
zipper (DNA helicase)
– New bases are added on to each side (DNA
Polymerase)
– Both new sets of DNA are glued back together
(DNA ligase)
DNA vs. RNA
DNA
• Deoxyribonucleic acid
– Deoxyribose sugar
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Double stranded
Double helix
Thymine
A pairs with T
RNA
• Ribonucleic acid
– Ribose sugar
• Single stranded
• Uracil instead of Thymine
• U still pairs with A just like T
would
Central Dogma
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DNA RNA amino acids (proteins)
DNA RNA is transcription inside nucleus
RNA proteins is translation in cytoplasm
Gene expression the transformation from
genes into expressed traits
RNA
• DNA CANNOT come out of the nucleus
• Three types:
– mRNA (messenger) gets transcribed from DNA, and
moves out of the nucleus
– tRNA (transfer) during translation, mRNA gets
converted into amino acids or proteins by the tRNA
– rRNA (ribosomal)cytoplasm consists of thousands
of ribosomes, and RNA found inside ribosomes is
called rRNA
• Ribosomes are made of up proteins
• Proteins that are made to be part of the ribosome are made
from rRNA
Transcription
• From DNA to mRNA
• Steps:
– RNA Polymerase binds to promoter region-start
– DNA unwinds
– RNA Polymerase uses one of the strands to make
its complementary strand of mRNA, and the DNA
double strands close back together
Translation
• From mRNA to proteins by way of tRNA
• Steps:
– Amino acid binds to correct tRNA with correct anticodon;
the mRNA joins ribosome and tRNA; mRNA
– A second tRNA with correct amino acid and anticodon bind
to the next codon on the mRNA strand, and a peptide
bond forms between the two amino acids; the first tRNA is
released from the ribosome
– The ribosome keeps moving down one codon at a time
until a string of amino acids are bound together
– A stop codon signals the end of the process
– Ribosome then releases from the mRNA, and is allowed to
bind to another starting translation again.
Proteins
• Essential to all living things
• Build structure and carry out metabolism
• Protein large, complex molecule composed of
carbon, hydrogen, oxygen, nitrogen, and usually sulfur
• Proteins are made up of amino acids
• There are 20 essential amino acids to all life
• Because of this, proteins can vary greatly in size, shape,
and types
• Two amino acids are joined together by peptide bonds
• Two or more amino acids joined together are called a
peptide chain
Genetic Code
• Codon: triplet set of bases, code for amino
acids based on chart
• Anticodon: the complementary set to the
codon
Mutations
• Point Mutations
• Frameshift mutations
• Chromosomal mutations