DNA and Protein SynthesisGoal: to understand the structure and function of DNA, its role in protein synthesis and evolution.Chapter 12 DNA

12.1 Identifying the Substance of Genes

Bacterial Transformation

Early biologist studying genetics wanted to know the chemical nature of __________.Griffiths

Through _____________ experiment scientists hypothesized the chemical compound that transformed the harmless bacteria into disease causing ones was most probably a gene.

Griffiths experiment discovered the process called __________________.Avery

Oswald Avery did further experiments to discover the _____________ _____________ of a gene.

By exposing the bacteria to ___________ that would destroy proteins, lipids, carbohydrates and RNA they discovered that neither of those was responsible for transformation.

It wasn’t until they used an enzyme to destroy ______ that they realized that _______ was the transforming factor.

Bacterial VirusesHershey - Chase

In the Hershey – Chase experiment scientists wanted to determine if the bacteriophage injected the __________ coat or the ________ core.

1

They tagged the bacteriophage with two types of _________ _________, phosphorus-32 and sulphur-35. Phosphorus is attached to ______ and sulphur is usually attached to _____________.

When they allowed the bacteriophage to enter the bacteria they discovered phosphorus inside the bacterial cells meaning ________ was genetic material.

The Role of DNA

DNA is capable of ___________ information in the form of genes.

DNA __________ the information stored in genes when cells divide.

When cells divide the information stored in genes is _______________ from one generation to the next.

12.2 The Structure of DNA

The Components of DNA

DNA is a nucleic acid made up of subunits called ______________.

A nucleotide is composed of a 5 carbon sugar called _____________, a ___________ group and a ______________ base.

There are four types of nitrogen bases; ___________, __________, __________ and ___________.

Nucleotides are joined together by ____________ bonds between the ____________ sugar and the ____________base.

Make a diagram of Figure 12-5 on page 345.

2

Solving the Structure of DNA

Chargaff’s rule states that there are _______ percentages of adenine and thymine and the same rule applies to __________ and __________.

Complete “Analyzing Data” on page 345 to check your comprehension.

The Double – Helix Model Franklin’s X-ray of DNA enabled Watson and Crick to

build a model that explained the ___________ and ____________ of DNA.

DNA is shaped in a double helix and looks like a _________ __________.

Each side of the ladder or strands of DNA run in opposite directions making it ____________.

The two strands of DNA are held together by ____________ bonds between the nitrogen bases.

The hydrogen bonds between the nitrogen bases occur only between complimentary base pairs; ______ and ______.

3

Make a diagram of Figure 12-7 Base Pairing on page 348

12.3 DNA Replication

Copying the Code

The process of copying the cell’s DNA is known as _____________.

Replication occurs during ___________ of the cell cycle before mitosis.

Replication is to ensure that each cell has an exact copy of _________.

During replication the two strands of DNA ___________ and each side is used as a template for a new strand

The adenine base bonds with ___________ and guanine bonds with ___________.

____________ (types of proteins) play a role in replication.

The helicase enzyme will “unzip” the DNA strands by breaking the __________ __________.

DNA ______________ will join nucleotides together by producing the sugar phosphate bonds.

DNA polymerase will also _________ ________ the DNA strands to make sure there are no copying errors.

4

Complete the Chapter 12 Assessment on pages 356-357 to check your comprehension

Chapter 13 RNA and Protein Synthesis

The Role of RNA

DNA has the codes to build a protein but these instructions must first be copied into ________.

RNA is similar to DNA in that it is made of _____________, however there are three important differences; RNA has a ______ sugar while DNA has a deoxyribose sugar, RNA has a _________ strand while DNA is double stranded and RNA contains the nitrogen base _________ in place of thymine.

There are __________ types of RNA and each has its own job to perform.

Make a diagram to match each type of RNA (figure 13-2)

___________ RNA carries the instruction to build a protein from the nucleus to the ribosome.

___________ RNA helps form the subunits of a ribosome (where protein synthesis takes place).

____________ RNA carries amino acids to the ribosome to match them to the coded mRNA message.

5

RNA Synthesis

_______________ is the process where DNA will serve as the template to make a strand of RNA.

The RNA will be made in the nucleus and then go to _____________ to help make a protein.

RNA ____________ is an enzyme that will bind to the DNA strand and cause it to separate.

One strand of DNA will act as a ___________ to make the RNA strand.

____________ are regions of DNA that signal the RNA polymerase where to begin making the RNA strand

mRNA often needs to be edited so the portions cut out are called _______ and the portions spliced together are call ________.

13.2 Ribosomes and Protein Synthesis

The Genetic Code

The code carried in DNA which is then transcribed into RNA is information to make a ____________.

Proteins are made by joining ________ _______ together in long chains called polypeptides.

The order of amino acids is directly related to the proteins _________ and __________.

RNA has four different bases: adenine, cytosine, guanine and _________ which makes form the base of a language we call the ________ code.

The genetic code is read three letters at a time and the three letters correspond to a specific ________ _______.

6

The three letter code on mRNA is called a _________. Often amino acids have more than one ________. Lysine

has two _______; AAA and AAG. The message to start and stop the process of making a

polypeptide is in the form of “_______” and “________” codons.

Complete the “Quick Lab” on page 367 to check your comprehension.

Translation

The role of a ribosome in the process called translation is to _________ the mRNA message into a sequence of amino acids to form a polypeptide and eventually a ____________.

The first step in translation is when the ribosome binds to the strand of ___________.

As each codon on the mRNA strand passes through the ribosome, _________ will bring the proper amino acid into the ribosome.

tRNA has ___________ (3 unpaired bases) that are complementary to the mRNA codons.

The codon for methionine is AUG so the anticodon would be ________.

The ribosome will create ________ bonds that will attach the amino acids together and as the bond

7

between tRNA and the amino acid break, tRNA will exit the ____________. More tRNA will enter the

ribosome bringing in amino acids specified by the ___________.

The process continues until the ribosome reaches a “stop” codon and then the polypeptide is ____________.

Please review the “Visual Summary” on page 368

The Molecular Basis of Heredity

Most genes contain the instructions to build _________. Proteins are microscopic tools designed to build and

operate the cell. The central basis of molecular biology is that

information is transferred from ______ to ______ to protein. The process is known as _______ expression.

Please review the “Visual Summary” Gene Expression on page 371.

13.3 MutationsTypes of Mutations

Mutations are changes in ___________ information.

8

Create questions that your notes answer. Highlight the answers in the notes. Try and “Guess the Test” and create questions that may show up on the test.

There are two types of genetic mutations; ________ and ______________ mutations.Gene Mutations

There are three types of gene mutations; ___________, ____________ and ____________.

These types of mutation usually only change one or a few nucleotides and are known as _________ mutations.

____________ occurs when on base is changed to another base. It can change the amino acid or have no change at all since amino acids have more than one codon.

_________ and __________ occur when a base is inserted or removed. These mutations will cause shift in the reading of the three letter code and as a result it can change every amino acid that follows the point of the mutation.

Insertion and deletions are also known as “__________ ___________” mutationsComplete “Analyze Data” on p 373

Chromosomal Mutations Chromosomal mutations can change the _________ of

genes on chromosomes or even the __________ of copies.

There are four types of chromosomal mutations: __________, __________, _________ and _____________.

___________ refers to a loss of all or part of a chromosome.

9

___________ produces an extra copy of part or all of a chromosome.

___________ refers to the changing of direction of parts of a chromosome.

____________ occurs when a part of a chromosome breaks off and attaches to another.

Effects of Mutations

Mutations usually occur during cell division and happen once in every _______ million bases.

____________ are agents that alter the genetic code or cause and increase in copying errors.

Mutations can be either __________ or beneficial and at times have no effect at all.

Harmful mutation can lead to faulty _________ or even cancer.

Beneficial mutations alter proteins and allow the organism survive in a changing environment.

Complete the “Quick Lab” on page 374

1.

2.

3.

10

List 5 examples of mutations and classify each as neutral, harmful, or helpful. Explain your reasoning.1.

2.

3.

4.

5.

Complete the Chapter 13 Assessment on pages 386 - 387

11

12

13

14