1. Biology Unit 4 Notes: RNA & Protein Synthesis

2. (1) What is Protein Synthesis?
The process of using the “code” in DNA to make proteins.
Happens in 2 parts:
Transcription
Translation

4. (2) Molecules & Locations
In the Nucleus:
DNA
mRNA
Outside the Nucleus:
tRNA
rRNA
Amino Acids

6. (3) What is RNA? A type of nucleic acid (like DNA).
RNA Nucleotides are made of:
Phosphate
Ribose Sugar
Nitrogenous Base
The 4 Types of RNA Bases are:
Adenine (A)
Uracil (U)
Guanine (G)
Cytosine (C)
RNA is 1 single spiraling strand.

7. (4) What happens in Transcription?
The “code” from DNA is transcribed (or copied) onto a molecule of mRNA (messenger RNA).
The cell matches up the bases from a strand of DNA, with RNA nucleotides to make the strand of messenger RNA.
No T’s (thymine)
Any place you would normally put a T, you put a U (for uracil) in RNA.

9. (5) Transcription Example
A strand of DNA has the following base sequence:
T A C - G G C - A T C
Write out the matching bases for the strand of mRNA:

10. (6) What happens in Translation?
The copied code on messenger RNA is used to sequence Amino Acids and make a protein.
mRNA leaves the nucleus.
Every 3 bases on mRNA matches up with a specific tRNA (transfer RNA).
Each specific tRNA brings in (or transfers) in a specific Amino Acid.
All parts move through the rRNA (ribosomal RNA) unit.
Amino Acids connected at the end to make a protein.

12. (7) Translation Example
A strand of mRNA has the following base sequence:
AUG - CCG - UAG
Write out the matching amino acids:

13. (8) Codons & Anticodons A codon is: 3 bases on messenger RNA.
An anticodon is: 3 bases on transfer RNA.
The codons on mRNA and the anticodons on tRNA must match up to bring in the correct amino acid sequence.

15. (9) Mutations
A mutation is when there’s a change to 1 or more bases in DNA.
Can be caused by: Genetics, random error, chemicals, radiation.
When the DNA bases change, the mRNA bases change. This brings in the wrong tRNA and Amino Acid. This makes the wrong protein. 