1. DNA DNA RNA Protein To create more cells replication transcription
For cell/organism function protein synthesis
RNA
translation
Protein
TedEd
Stated Clearly

2. All cells must copy and interpret some of the DNA code to make the proteins needed for life
…so these can function
cell
chromosome
body
nucleus
double helix
gene
Act on this code..
DNA Rap

3. RNA is a nucleic acid with a slightly different structure
Single helix
Ribose sugar vs deoxyribose of DNA
uracil pairs with adenine during RNA synthesis

4. Function of each differs, but are complementary
RNA
rewrites and interprets the code as proteins
multiple types of RNA
DNA
segments of the sequence
- genes - code for proteins

5. Gene code in the
DNA
is transcribed into
RNA
which is translated into a
protein
transcribe = rewrite
translate = change the language

6. 3 Types of RNA interact to synthesize proteins:
• Messenger RNA mRNA
Copy of DNA
carries gene code to cytoplasm
• Ribosomal RNA rRNA
Makes ribosome
brings together mRNA and tRNA
• Transfer RNA tRNA
Brings amino acid to make polypeptide (protein)
tRNA
Protein
rRNA

7. Keep DNA safe in nucleus ‘master copy’
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
mRNA
DNA
nuclear membrane pores
Electron Microscopy: Nuclear Pore Complex
Nuclear Pore Complexes (NPCs) seen from the nucleoplasmic side. The cage (also called basket) structure is clearly seen in this view as rings connected with the pore with eight fibers. The large globular structures, sometimes seen on top of and sometimes seen inside the cage, are RNP particles (mRNA+protein) being transported from the nucleus to the cytoplasm through the NPC.
Why an RNA copy?
Keep DNA safe in nucleus ‘master copy’
Multiple copies, all making protein (= more protein, faster)

8. mRNA is created from the DNA template in the process of transcription
This single helix nucleic acid can leave the nucleus
Animated
HHMI transcription

9. mRNA carries the code from the nucleus to ribosomes
Large ribosome subunit and small ribosome subunit fit together around the mRNA

10. Translation of the code occurs at the ribosomes:
• mRNA & tRNA base pair (codon to anticodon)
• amino acids are sequenced and bonded into a polypeptide
peptide covalent bonds
polypeptide chain
amino acid
tRNA
anti-codon
codons
mRNA
ribosome
Animation
Start at 0:23; Sound off
HHMI translation

11. Pairs of nt (42 combos) = 16 aa’s Triple nt (43 combos) = 64
Why codons of three? A U C G
1nt : 1aa = 4 aa’s
Pairs of nt (42 combos) = 16 aa’s
Triple nt (43 combos) = 64
more than enough to code for 20 amino acids
Triplicate Code

12. The code is redundant, but it is never ambiguous
STOP CODONS
START CODON
The code is redundant, but it is never ambiguous

13. DNA
mRNA
Polypeptide
3D polypeptide
Protein
DNA makes Proteins

15. Changes to the DNA code – mutations - can mean changes to the protein

16. Point mutation/substitution

17. Frameshift mutations result from insertion
or deletion of 1 or 2 nucleotides