dna: the genetic material the instructions for inherited traits are called genes dna: primary...
DESCRIPTION
The Shape of DNA A DNA molecule looks like a spiral staircase and is composed of two parallel strands of linked subunits called nucleotidesTRANSCRIPT
DNA: The Genetic Material• The instructions for
inherited traits are called genes
• DNA: primary material that causes recognizable, inheritable characteristics in related groups of organisms
The Shape of DNA
• A DNA molecule looks like a spiral staircase and is composed of two parallel strands of linked subunits called nucleotides
The Shape of DNA• A nucleotide has 3 parts:
phosphate group, sugar (deoxyribose), and a base
• The phosphate and sugar link together to form the back bone
• The bases pair together to connect the two strands
DNA Replication
• Step 1: Unwind and Separate the DNA Strands – Two complementary strands of DNA separate from
each other and form Y shapes called replication forks• Step 2: Add Complementary Bases – At the replication fork, new nucleotides are added to
each side according to the base-pairing rules• Step 3: Formation of Two Identical DNA
Molecules– Each double-stranded DNA helix is made of one new
strand of DNA and one original strand of DNA
Base Pairing Rules
Replication Proteins• DNA Helicase – enzyme that unwinds DNA• DNA Polymerase – enzyme that adds nucleotides to each
base to form two new double helixes; proofreads
http://www.youtube.com/watch?v=zdDkiRw1PdU
Gene Expression
• The manifestation of genes into specific traits
Two Steps: • Transcription • Translation
Transcription
• Location: nucleus
• Makes mRNA from DNA
• After mRNA is made it travels into the cytoplasm
Codon
• 3 letter code on mRNA
• Pairing rules with DNA– A – U (Uracil)– T – A– C - G
Translation• Makes protein from
mRNA in cytoplasm on a ribosome
• tRNA carries anticodons to codons which code for an amino acid
• rRNA helps to make protein
Translation
What amino acid does each codon represent?
• UUG
• GUA
• CAC
• ACU
• AGG
• CCG
= Leucine
= Valine
= Histidine
= Threonine
= Arginine
= Proline