Aim: How does a chromosome code for a specific protein ?

HW read pages 300 - 306

Answer ques. #1-5

section 12-3 pg 306

Hydrogen bonds

Nucleotide

Sugar-phosphate backbone

Key

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

DNA is made up of chains of nucleotides

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RNADNA

RNApolymerase

DNA makes RNA - Transcription

Adenine (DNA and RNA)Cystosine (DNA and RNA)Guanine(DNA and RNA)Thymine (DNA only)Uracil (RNA only)

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RNA makes Protein

Messenger RNA

.

mRNA

Ribosomal RNA

tRNA

Nucleus

Three types of RNAmRNA, rRNA, tRNA

Section:Codon

Amino AcidsAmino acid

mRNA

Importance of Base Sequence

DNA has the following sequence of nucleotides

GACAAGTCCACAATC

mRNA

CODON – 3 nucleotides on mRNA that specify a particular amino acid

m RNA CUGUUCAGGUGUUAG

t RNA

The Genetic CodeSection 12-3

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GAC

AAG

UCC

AAC

AAU

CGG

Proteins are made from amino acids

• A total of 9 amino acids are considered essential (must be ingested), while another 11 or so nonessential can be synthesized by cells.

• Essential amino acids : Histidine, isoleucine, Leucine, lysine, methionine phenylalanine, threonine tryptophan, and valine

• Nonessential amino acids: Alanine, arginine, aspartic acid, cystine, glutamic acid, glycine, proline, serine, and tyrosine

The Polypeptide “Assembly Line”

mRNARibosome

Translation direction

Lysine tRNA

tRNA

Ribosome

Growing polypeptide chain

mRNA

Completing the Polypeptide

Section 12-3

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Importance of polypeptide chain protein

Importance of protein synthesis

The cell goes to a lot of trouble to synthesize proteins correctly because proteins define what the cell looks like, how it functions, how it grows, and how it passes this information to its daughter cells

Which statement best expresses the relationship between the three structures

represented below?

(1) DNA is produced from protein absorbed by

the cell.(2) Protein is composed of

DNA that is produced in the cell.(3) DNA controls the

production of protein in the cell.(4) Cells make DNA by

digesting protein.

The diagram below shows some of the steps in protein synthesis.

The section of DNA being used to make the strand of mRNA is known as a

(1) carbohydrate

(2) ribosome

(3) gene

(4) Chromosome

The site of protein synthesis is the

The types of human cells shown below are different from one another, even though

they all originated from the same fertilized egg and contain the same genetic information.

Explain why these genetically identical cells can differ in structure and function.