1. RNA & Protein Synthesis
Lecture

2. How are babies made? 쓰지마. Meiosis Gametes Sex/fertilization Zygote
DNA Replication, Cell Division / Mitosis
“Growth” (new cellsmitosis)

3. How are cells / bodies built?
DNA Replication just makes more DNA.
Proteins…

4. What are proteins and what do they do? Reading Activity:
Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs.
Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein. The sequence of amino acids determines each protein’s unique 3-dimensional structure and its specific function.

5. Proteins can be described according to their large range of functions in the body, listed in alphabetical order:
Examples of protein functions
Function
Description
Example
Antibody
Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body. 
Enzyme
Enzymes carry out almost all of the thousands of chemical reactions that take place in cells. They also assist with the formation of new molecules by reading the genetic information stored in DNA.
Phenylalanine hydroxylase
Messenger
Messenger proteins, such as some types of hormones, transmit signals to coordinate biological processes between different cells, tissues, and organs.
Structural component
These proteins provide structure and support for cells. On a larger scale, they also allow the body to move.
Muscle fiber protein:
Transport/storage
These proteins bind and carry atoms and small molecules within cells and throughout the body.
Ferritin

6. How are proteins made? 쓰세요:
DNA carries master plan
Plan is read & rewritten into a blueprint (sequence of bases code)
Blueprint (mRNA) instructs builders
Amino acids linked according to codes from Blueprint  Proteins built!

7. RNA Structure Ribonucleic Acid: Like DNA Unlike DNA
Long chain of nucleotides
No Thymine (no “T” base)
RNA Nucleotides = sugar, phosphate, nitrogen base
Sugar is ribose, not deoxyribose
Copied from DNA
Single-stranded

8. 3 Types of RNA Messenger RNA (mRNA) Ribosomal RNA (rRNA)
Transfer RNA (tRNA)

9. Messenger RNA (mRNA) Serve as “messengers” from DNA
Carry copies of instructions (blueprints) out of the nucleus
Coded to assemble amino acids into protein chains (polypeptides)

10. Ribosomal RNA (rRNA)
Ribosomes are the machines that read mRNA and construct polypeptides (proteins) from amino acids.
Ribosomes are comprised of
two subunits.
Made of rRNA and
proteins.

11. Transfer RNA (tRNA)
tRNA: Carries & transfers each amino acid to ribosome as coded by mRNA.

12. Transcription
RNA Polymerase (an enzyme) binds to DNA and separates strands.
Then uses one strand of DNA to assemble a single-stranded mRNA molecule.

13. Transcription
Results in a single-stranded messenger RNA (mRNA) which carries the code for building proteins out of the nucleus to ribosomes.

14. mRNA

15. Keep to the CODE!
mRNA transcription
No Thymine in RNA base sequences:

16. Uracil in RNA base sequences:
In DNA: AT & GC
In RNA: AU & GC
U = Uracil
Messenger RNA (mRNA) strand might read:
AAUGCCUAC

17. Practice: Transcribe DNA to mRNA
You are RNA Polymerase (the enzyme).
DNA: TTACGGATG
RNA: AAUGCCUAC
DNA: CCGTTCATG
RNA: GGCAAGUAC
DNA: GATGGGATA
RNA: CUACCCUAU

18. The Genetic Code
DNA: TTACGGATG
RNA: AAUGCCUAC
Each set of three bases corresponds with a specific amino acid.
Each triplet is called a codon.
AAU – GCC – UAC
AAU = Asparagine
GCC = Alanine
UAC = Tyrosine

19. Translation is…
the decoding of an mRNA message into a polypeptide (protein) chain.
Again, each tRNA carries one amino acid
tRNA has an RNA anticodon corresponding & bonding to each mRNA codon
mRNA: CUA-CCC-UAU
tRNA: GAU-GGG-AUA

20. Translation uses all three types of RNA
mRNA (messenger copies from DNA) binds with a ribosome (rRNA), which is the machine that builds polypeptides when tRNA transfers amino acids by matching its anticodon to the mRNA codon.

22. Translation mRNA message: UUCAUCGUACGC Amino acids:
____ ____ ____ ____

23. Transcription to Translation
DNA in the nucleus:
CCGAAGTTCATG
mRNA brings:
GGCUUCAAGUAC
…to ribosome
tRNA brings…
Amino acids:
Gly-Phe-Lys-Tyr
…forming part of a protein.