Download File - From DNA to Proteins

PROTEIN SYNTHESIS
QUICK WRITE
Think back to when we learned first learned about
macromolecules at the beginning of the school year.
What are proteins and why are they important? What
do you think would happen if our bodies could not
make proteins?
* You will have about 2½ minutes to complete write
(the length of this song)
FIND THE DIFFERENCES
(THERE ARE AT LEAST TWO DIFFERENCES)
DNA VS. RNA
DNA
(Deoxyribonucleic
Acid)
RNA
(Ribonucleic Acid)
Sugar
Deoxyribose
Ribose
Bases
A – Adenine
T – Thymine
C – Cytosine
G – Guanine
A – Adenine
U – Uracil
C – Cytosine
G - Guanine
Double Stranded
Single Stranded
# of strands
RNA
Function
Messenger RNA
(mRNA)
Transfer RNA
(tRNA)
Carries message
from DNA to
make proteins
Brings amino
acids to
ribosomes to
make proteins
Ribosomal RNA
(rRNA)
Makes up a
large of portion
of ribosomes
and helps bind
the mRNA
Appearance
Images from: Miller, K.R. & J.S. Levine. Biology. Pearson Prentice Hall.
KAHOOT!
Take out phones or ipods and go to site kahoot.it
Wait for class code to join
CENTRAL DOGMA
DNA ------------------> RNA ------------------> Protein
transcription
translation
Analogy:
DNA: Coca-Cola’s secret recipe is locked inside a
vault
RNA: Someone takes parts of the recipe and
directions out of the vault so that it can be made
Protein: With the directions, machines and workers
make Coca-Cola drinks
TRANSCRIPTION
• DNA  RNA
• Occurs in the nucleus
• RNA polymerase makes a single-stranded copy of
the DNA called messenger RNA (mRNA)
• The mRNA contains information for 1 protein
• mRNA leaves the nucleus while the DNA stays in the
nucleus
mRNA is transcribed in the nucleus from
DNA with the help of RNA polymerase
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
RNA
polymerase
RNA
DNA
Image from: Miller, K.R. & J.S. Levine. Biology. Pearson Prentice Hall.
mRNA leaves nucleus and enters the
cytoplasm
nucleus
mRNA
Image from: Miller, K.R. & J.S. Levine. Biology. Pearson
KAHOOT!
TRANSLATION
• RNA  Protein
• Occurs on ribosomes
• A protein is made when the mRNA is read by
ribosomes and appropriate amino acids are joined
together
• A polypeptide is a string of amino acids that make
a protein
mRNA attaches to ribosomes and translation begins at the
start codon (AUG)
tRNA brings the amino acid that corresponds to the codon
to the ribosome
Amino Acid
Amino Acid
tRNA
Amino Acid
Ribosome
mRNA
Start codon
Image from: Miller, K.R. & J.S. Levine. Biology. Pearson
Ribosome joins amino acids into a polypeptide
tRNA leaves ribosome after its amino acid is added
to the polypeptide
Amino Acid
mRNA
ribosome
tRNA
Translation direction
Image from: Miller, K.R. & J.S. Levine. Biology. Pearson Prentice Hall.
Polypeptide continues to grow until the ribosome reaches a
stop codon (UGA, UAA, UAG)
Once the stop codon is reached, the protein is finished and
released. The ribosome detaches from mRNA
Growing polypeptide chain
Ribosome
tRNA
mRNA
Image from: Miller, K.R. & J.S. Levine. Biology. Pearson Prentice Hall.
KAHOOT!
AMOEBA SISTERS VIDEO
• https://www.youtube.com/watch?v=h5mJbP23Buo
THINK-WRITE-PAIR-SHARE
Our bodies can only make a few of the 20 amino
acids. Where do you think we get our bodies get
amino acids? What do you think would happen if we
were not able to obtain all of the amino acids?