DNA and GenesSection 11.1 - DNA: The Molecule of Heredity

In This Section . . .What is DNA?

The Structure of DNA

DNA Replication

What is DNA?_____________________

DNA is the _________ of all living organisms. It controls how tall, what color, what sex, and every trait that the organism expresses

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DNA & ProteinDNA controls the organism through the production of __________

Proteins in the form of ________ are responsible for all functions of life. Walking, eating, blood clotting, thinking, and anything else that the organism does is affected by proteins

Watson and CrickPublished an article detailing the __________ of DNA

______________ structure with specific pairing.

Photo: Marjorie McCarty

DNA can hold a lot of information because they are polymers.

DNA is a polymer made of repeating subunits called ____________.

Nucleotides have three types of subunits:

A Simple ______

A __________ Group

A Nitrogen Base

The Structure of DNA

P

Sugar

NitrogenBase

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The Sugar Group

The sugar group found in DNA is ____________

The Phosphate Group

The Phosphate group is composed of a phosphate atom surrounded by 4 atoms of ___________

P

O

O O

O

Nitrogen BaseA carbon ring structure that contains one or more atoms of nitrogen.

4 types of bases in DNA

_________

_________

_________

_________

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How do DNA Molecules Join?

The phosphate group of DNA binds to the sugar group to form a _________ for DNA

NitrogenBaseP

Sugar

NitrogenBaseP

Sugar

Sugar-PhosphateBackbone

The Order Spells it All!All chromosomes are composed of the same substances regardless of their host organism. A toad has the same genetic material as a bird.

The order of the _________ bases determines the organism’s traits.

A-T-T-C carries different information than A-A-A-T-C (Just like writing words).

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Replication of DNAAll organisms must _________ DNA in order to survive.

Every time a cell undergoes _______ or ______, DNA must be replicated

Replication of DNA

AATTTCGCCAAATTTAAAGCGGTTTA

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In Review . . .What is DNA?

The Structure of DNA

DNA Replication

DNA and GenesSection 11.2 - From DNA to Protein

In This SectionGenes and Proteins

RNA and its functions

Transcription

Translation

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Genes and ProteinsThe sequence of DNA information in the chromosomes is put into action through __________.

Proteins are three-dimensional figures that perform a specific function based on their shape.

Proteins are used by organisms for structural support and as __________.

Proteins are made of amino acids that are bonded by peptide bonds

RNARNA is also a ______________ (like DNA)

There are 3 ways in which RNA differs from DNA

RNA is _______ stranded

The sugar in RNA is Ribose instead of deoxyribose

RNA has _______ instead of thymine

Courtesy of: National Human Genome Research Institute (NHGRI) by artist Darryl Leja

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RNAThere are three types of RNA

__________ RNa (mRNA): brings “messages” from the DNA to the cytoplasm

__________ RNA (rRNA): Helps ribosomes connect to mRNA

__________ RNA (tRNA): Transports the amino acids to the ribosomes

TranscriptionTranscription is a process that occurs in the __________ of the cell.

An enzyme called RNA ____________ makes an RNA copy of a portion of DNA.

That RNA strand is sent out to the cytoplasm as mRNA

RNA Polymerase

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The Genetic CodeThere are only Four different bases on which to base the entire genetic language.

The combination of these bases determines the ___________ that it codes for.

Genetic words are called ______ and they are spelled by three bases (genetic letters).

There are 64 possible codons that can be spelled by the bases.

Codons are coded for either an amino acid OR a special function, like ____ and _____.

More Words than NeededThere are only 20 amino acids and 64 genetic codes for those amino acids.

That means that some amino acids have more than one code.

You will need to know the stop and start codons found on page 298 in your book.

TranslationTranslation is a process of turning the genetic message of ________ into a protein. (You translate it from a nucleic acid language to a protein language).

Translation takes place at the __________ in the cytoplasm

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The Role of tRNAIn order for amino acids to be bonded, ______ must bring the amino acids to the ribosomes.

There is only ____ tRNA for each amino acid. T

T TTSTOP

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In ReviewGenes and Proteins

RNA and its functions

Transcription

Translation

DNA and GenesSection 11.3 - Mutations

In this Section . . .What are mutations?

The Types of Mutations

DNA Repair

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What are Mutations?Any change in the DNA __________

If they are in any part of the body (other than gametes), they aren’t passed on to the next __________.

“In some rare cases, a gene mutation may have positive effects. An organism may receive a mutation that makes it faster or stronger; such a mutation may help an organism - and its offspring - better survive in its environment.” Biology, the Dynamics of Life pg. 303

Mutation FactsIt’s estimated that over 99% of mutations are _________ and over 90% are lethal to the organisms which contain them.

Mutational changes have definite _______ which they can not transgress

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Mutations in Non-Reproductive Cells

Radiation may cause damage to a gene that impairs its ________.

When the mutated cells go through __________, the mutated genetic code is passed on

Mutations in Non-Reproductive Cells

Many Scientists believe that the build up of these mutations is the cause of ________.

If the mutation takes place in the genes that control the cell cycle, it can result in _________

Types of MutationsPoint Mutations

Frameshift Mutations

Chromosomal Mutations

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Point MutationsA Point mutation is a change in a single __________ pair of DNA.

This may or may not result in a change in a protein by one amino acid.

Changing one amino acid can change the _________ and function of the protein.

Consider the following sentences:

“THE DOG BIT THE CAT”“THE DOG BIT THE CAR”

Frameshift MutationsA Frameshift mutation is when a ____________ is lost or added to a DNA strand.

This causes a shift in the genetic code and can result in a significant change in the mRNA during the process of transcription.

These are worse than Point Mutations because Point mutations only affect one _______________

Consider the following example

“THE DOG BIT THE CAT”“THE DOB ITT HEC AT”

Chromosomal MutationsThese are mutations that occur at the _____________ level instead of at the level of the genetic code.

Sometimes parts of chromosomes break off during mitosis and then rejoin incorrectly

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Chromosomal Mutations4 Types:

________: When a part of the chromosomes is left out (deleted).

________: When a part of a chromatid breaks off and attaches to its sister chromatid (inserted).

__________: When part of the chromosome breaks off and is reinserted backwards (inverted).

___________: When part of the chromosome breaks off and is added to a different chromosome (translocated).

Causes of mutationsSome mutations seem to happen, perhaps as a mistake in base pairing during DNA replication. These are said to be Spontaneous.

Some mutations are caused by factors in the environment.

_________ are the factors in the environment that cause mutations.

Examples:

Chemicals (asbestos, benzene, cyanide, etc)

Repairing DNACells have enzymes that ____________ the genetic code and correct the mistakes that are found.

The greater the exposure of the enzymes to a mutagen, the more likely is the chance that a mistake will be made.

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In Review . . .What are mutations?

The Types of Mutations

DNA Repair

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