Protein Synthesis

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