Question of the Question of the DayDay

4-191. DNA replication and

transcription occur in the _______, while translation occurs in the _______.

REVIEWREVIEW1. The 3 parts of a nucleotide = …

2. Cytosine pairs with _____ in DNA.

3. Monomer of a protein =

REVIEWREVIEW Peptide BondPeptide Bond – –

– Covalent bond (sharing Covalent bond (sharing electrons) formed between two electrons) formed between two amino acidsamino acids

What holds nitrogenous bases What holds nitrogenous bases together?together?

– – hydrogen bondshydrogen bonds

DNADNA

The process of copying DNA = …The process of copying DNA = …

– – DNA replicationDNA replication

REVIEWREVIEW

Enzyme that breaks hydrogen bonds between nitrogenous bases = …

Enzyme that adds nucleotides to form a new strand of DNA = …

REVIEWREVIEWHelicaseHelicase – –

Replication ForkReplication Fork – – – location where the DNA is splitting location where the DNA is splitting

apartapart

REVIEWREVIEW

Question of the Question of the DayDay

4-201. Transcription makes ________

from DNA and then _________ makes proteins from _________.

AnnouncementAnnouncement4-20

Unit # 8 Test will NOT be Friday 4-29 but sometime the following week!

AssignmentsAssignments4-20

Skim (read over) section 10.3 and complete questions #s 1-8 at the bottom of page 202 – my.hrw.com. – due NOW

Webquest – DNA Transcription and Translation – due NOW

What is a codonWhat is a codon??Codon = Codon = Three nitrogen bases that Three nitrogen bases that

code for an amino acidcode for an amino acid There are “There are “startstart” and “” and “stopstop” ”

codonscodons The code is the exact same as The code is the exact same as in in

humans as in a virus or a skunkhumans as in a virus or a skunk Scientist see this as evidence that Scientist see this as evidence that

we all share a common ancestorwe all share a common ancestor

PracticePractice:: What is UUU?What is UUU? What is the start codon?What is the start codon?

PracticePractice::What is UGA?What is UGA?What are the stop What are the stop codons?codons?

Translation – Step by StepTranslation – Step by Step

A ribosome attaches to the mRNA strand and tRNA molecules bring specific amino acids to the ribosome.

Translation – Step by StepTranslation – Step by Step

AUG (methionine) signals the start of protein synthesis.

Translation – Step by StepTranslation – Step by Step

tRNA molecules continue along the mRNA strand bringing with them the corresponding amino acids. The amino acids are connected by peptide bonds

After the peptide bond is formed, the ribosome slides along to the next codon. The tRNA no longer carrying an amino acid is released, and a new tRNA carrying another amino acid can attach.

TranslatioTranslation – Step n – Step by Stepby Step

Translation – Step by StepTranslation – Step by Step

A chain of amino acids is formed until a stop codon is reached on the mRNA strand.

Translation SummaryTranslation Summary

http://www.youtube.com/watch?v=d1UPf7lXeO8

http://www.youtube.com/watch?v=FUA6_Ucw3i4

DNA SONGS:DNA SONGS:

Question of the Question of the DayDay

4-261. What is a codon? Where

is it found?

2. What is an anticodon? Where is it found?

AnnouncementAnnouncement4-26

Unit # 8 Test will be Tuesday 5-3!

Transcription and TranslationTranscription and Translation

AssignmentsAssignments4-26

Handout with book assignment at the end – due Thursday 4-28

AssignmentAssignment4-18

Handout

Skim (read over) section 10.3 and complete questions #s 1-8 at the bottom of page 202 – my.hrw.com.

A ribosome attaches to the mRNA strand and tRNA molecules bring specific amino acids to the ribosome.

A ______________ attaches to the mRNA strand and _______________________ bring specific amino acids to the ribosome.

AUG (methionine) signals the start of protein synthesis.

_________ (_______________) signals the start of protein synthesis.

tRNA molecules continue along the mRNA strand bringing with them the corresponding amino acids. The amino acids are connected by peptide bonds

____________________________________________________________ bringing with them the corresponding amino acids. The amino acids are connected by ___________________

After the peptide bond is formed, the ribosome slides along to the next codon. The tRNA no longer carrying an amino acid is released, and a new tRNA carrying another amino acid can attach.

After the peptide bond is formed, ________ ____________________________________. The tRNA no longer carrying an amino acid is released, and ______________________ ____________________________________.

A chain of amino acids is formed until a stop codon is reached on the mRNA strand.

A chain of amino acids is formed until a ______________________ is reached on the mRNA strand.