Unit 6: DNA & Protein Synthesis

Name ______Date ______

Mrs. Geithner-Marron Bio 200 Period ______

Unit 6: DNA & Protein Synthesis

Ch. 28 DNA—Life’s Code

Describing DNA

•Who were the first people to describe DNA as a double helix shape?

–______& ______

•A double helix looks like a ______.

DNA is a Polymer…

•What is the monomer that repeats to make DNA? ______

What are the parts of a nucleotide?

•

–4 kinds:

•

–Trick to remember the 4 kinds of nitrogen bases… ______

•SKETCH what a nucleotide looks like….

A Model of DNA

•A DNA molecule is:

–______-stranded

•“backbone” =

•“rungs” =

–Always paired as:

Where is DNA found in eukaryotic cells?

•

DNA Replication

•What is another word for replication???

–

•Why must DNA replicate?

–

•When does DNA replicate?

–

•Where does DNA replicate?

–

•How does DNA replication occur?

–1. DNA molecule ______

–2. “parent” strands act as a______…

•______are paired up with ______on the “parent” strand

–form complementary ______strand

»Ex. ______

•3. ______of the original DNA moleculeare formed.

•When the cell divides, each daughter cell ______.

Finish the replications…

Deoxyribonucleic Acid vs. Ribonucleic Acid

DNA / RNA
• sugar = / • sugar =
• stranded / • stranded
• leave nucleus / • between nucleus & cytoplasm
• N bases = / • N bases =

The DNA Code & Protein Synthesis

•What is a gene?

•Which part of DNA actually carries the code?

–

•change the sequence  change the amino acid  change the protein

•So, the big question is… how does the DNA code in a cell’s nucleus get to the ribosomes where proteins are synthesized?

–

Transcription

•Occurs:

– when ______

–There are ______different amino acids, but DNA has only ______kinds of bases

–in ______

•which is where the DNA code is ______

•Produces ______from instructions in ______

–1. DNA ______

–2.

•until a ______is reached

–3. mRNA ______

mRNA

•______consecutive bases on mRNA

–code for an ______

•called______

–a chart tells us amino acid for each codon

Translation

•Occurs:

–when ______

–in ______

______on ______:

–joins with ______

–carries the ______to the ribosome

The amino acids ______

•What would the mRNA strand look like?

•What amino acids would be coded for using this mRNA?

•What would the anticodons on the tRNA be for each amino acid?

•Given the following DNA sequence determine:

–The mRNA codon sequence

–The amino acids that would be coded for by each codon

•Also determine the tRNA anticodon for each amino acid

–DNA = TAC CCA TTG GAT CCG ACT

–mRNA =

–A. A. =

–Anticodon =

Mutations

•Are ______on a chromosome

–can occur spontaneously during ______

–can be caused by ______

•often corrected, but not always

•once occurs, it is ______

–can cause a different ______to be formed

Types of Mutations:Deletion & Insertion

•deletion a nucleotide is ______

•insertiona nucleotide is ______

•“frame shift”causes different______

•which results in a ______being made

Types of Mutations: Point

•point mutation one base is ______

Sickle Cell Mutation

•affects ______caused by ______changes ______