PART THREE TRANSCRIPTION & TRANSLATION: HOW DNA MAKES YOUR TRAITS ROBERT PERRY Malibu High School
HOW DOES DNA MAKE YOUR GENETIC TRAITS ? ( HOW DOES INHERITANCE ACTUALLY WORK ?)
WHAT ARE GENETIC TRAITS ?
The traits which organisms inherit from their parents are proteins. Living things are a) made out of protein and they are b) controlled by proteins. YOU INHERIT BOTH STRUCTURAL and REGULATORY PROTEINS FROM YOUR PARENTS DNA.
WHAT ARE GENETIC TRAITS ?
All of the proteins found in every living organism are made of these same 20 amino acid building blocks.
THE 20 AMINO ACIDS:
WHAT ARE GENETIC TRAITS ?
A TYPICAL PROTEIN:
The same 20 amino acids make up all proteins.
DNA makes protein: 1. Transcription
DNA code is copied to mRNA in the nucleus.
1. Transcription. unwinding point
DNA
C
C
A
T
rewinding point
G
T T A
A C G
T
codon
T G
G C
A
C
U
T
A
U
C
C
A
A
G
G
T
A
C
A C C
mRNA
U A
G
note “U” replaces “T” in RNA
RNA polymerase
Each triplet of mRNA code letters is called a codon
1- transcription
mRNA transcript
NUCLEUS
DNA code
2- translation
amino acid chain (=PROTEIN)
RIBOSOME
mRNA transcript
2- translation
1- transcription
primary mRNA
secondary mRNA
DNA makes your traits PART TWO: TRANSLATION !
met
tRNA brings the particular amino acid specified by the mRNA codon. g ar
met
met
arg
ile
amino acids join to form a new protein
tRNA transfers an amino acid then moves away.
amino acids
new polypeptide chain tRNA codon a co nti do n
ribosome
final mRNA
A G
U
his
pro
G
pro
G
G G stop
ile
pro
met
A
C
U
A
U
U A G
U
A
C
G
G
G
A
U
G
C
C
C
U
G
C
A
G
U
THE END