QUARTERLY # 3- CHECK LIST

DNA

-Describe the 3 components of a nucleotide = deoxyribose sugar + phosphate + nitrogen base

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-Describe the structure of the DNA model helix

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-Evaluate the contributions of:

-Chargaff (N-base pairing rules_

-Franklin & Wilkins (X-Ray photograph)

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- In helping Watson & Crick determine the double helix structure of DNA.

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-Relate the role of the complementary base-pairing rules to the structure of DNA = (C-G) and (A-T) -- Purines(A/G) vs Pyrimidines (T/C)

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-Summarize the process the DNA Replication

-1 - The 2 original strands separate with DNA Helicase at Replication Fork

-2 - DNA Polymeraseadds complementary nucleotides to each strand

- 3 - The 2 DNA molecules that form are identical to the original DNA

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Describe how errors are corrected during DNA replication

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RNA - PROTEIN SYNTHESIS

-Proteins are made by decoding information on the DNA molecule/gene

Gene Expression  Genetic Code is nearly universal

-Compare the structure of RNA with DNA

Single Strand instead of double strand Uracil (U) instead of T

- Transcription: transfers information from DNA  RNA

Summarize the process of Transcription (in Nucleus)

1 - RNA Polymerase binds and the 2 DNA strands unwind and separate

2 - Complementary RNA nucleotides are added  form mRNA strand

 mRNAcarries instructions for making proteins from gene(Nucleus) and delivers it to the site of translation (Ribosome)

- Translation: correct amino acids are joined to form a protein

-Relate the role of Triplet Codons/Anti Codons to the

-sequence of Amino Acids that result after Translation

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Summarize the process of Translation (at the Ribosome)

1 - The mRNA and tRNA bind together....methionine is start codon

2 - tRNA carrying the Amino Acidsspecified by codon /anticodon arrives

3 - Peptide bond forms between adjacent Amino Acids

4 - tRNA detaches and leaves Amino Acid behind

5 - Process is repeated until stop codon is reached

6 - Ribosome complex falls apart.....newly made Protein is released - FOLDED  FUNCTION

DIAGRAMS

TRIPLET CODON CHART - EXAMPLE

- Prokaryotic and Eukaryotic cells are able to control which genes are expressed and which are not....depending on the cell’s needs.

- Prokaryotes- Gene expression regulated by OPERONS.

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- Switched off when REPRESSOR Proteins block RNA polymerase from transcribing a gene.

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- Eukaryotes - An ENHANCER must be activated for gene expression.

Transcription factors initiate transcription by binding Enhancersto RNA Polymerase

- Eukaryotic Genes - interrupted by:

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- segments of DNA that do not code for protein INTRONS (cut out)

- segments of DNA that are expressed EXONS (joinedtranslated)

- MUTATIONS - changes in DNA  AA sequence  Protein function

POINT MUTATIONS -

Substitution of a 1 /few nucleotide(s)

FRAMESHIFT MUTATION - Insertion/Deletion of a 1/more nucleotide(s) -

Gene read in wrong codon sequence

HEREDITY

-Heredity vs Genetics

-Mendel’s Experiments - contrasting traits in pea plants (P= parental generation)

1 trait shown in F1generation  other trait appeared in F2generation (3:1)

- Mendel’s Theory – 2 alleles/gene -- inherited from parents

Dominant = trait expressed (T) Recessive = not expressed (t)

Homozygous =(tt or TT) Heterozygous = (Tt)

-Law of Segregation- 2 alleles for trait separate with gamete (egg/sperm) formation

-Law of Independent Assortment - 2 or more pairs of alleles separate independently

of one another during gamete formation

-Punnett SquaresProbabilities Genetic crosses - prediction tools

Test Cross: To determine if dominant trait is heterozygous or homozygous

Monohybrid Cross (1 pair contrasting traits - Ex: Tt x TT)

Dihybrid Cross (2 pairs of contrasting traits - Ex: TtYy x TTYY)

Genotype = set of alleles/ gene combination (Tt)

Phenotype = observable expression of genotype - physical appearance of trait (Tall)

Pedigrees –– family history - inherited traits over many generations

O = female [] = male

- interpretation- trace genetic disorders

- Sex-Linked: Trait for gene carried by either male or female - usually X chromosome - most recessive- (Ex: Hemophilia) [Male= XY Female=XX]

-Patterns of Heredity - Phenotype influenced.

Polygenic Trait - Several genes on different chromosomes influence trait (Ex: Eye Color)

Incomplete Dominance - Display of intermediate trait (Ex: Pink Flowers)

Co-dominance - 2 dominant alleles expressed at same time (Ex: Roan Horse)

Multiple Alleles - 3 or more alleles control traits - individual can only have 2 alleles

(Ex: Blood Types: AO - BO - OO - AB) (Rh+/Rh-) Antigens vs Antibodies

Environmental Influence: temperature/pH (Ex: Artic Fox/ Hydrangea)

-Genetic Disorders: Sickle Cell - Tay Sachs - Cystic Fibrosis Genetic Counseling

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GENE TECHNOLOGY

-Biotechnology:

-Genetic engineering (Ex: Insulin)

4 steps: 1 - DNA cutrestriction enzymes (“scissors”) vector carries genes into new cell

plasmids (circular DNA in bacteria)

2 - Gene Splicing/Recombinant DNA is produced DNA ligase (“glue”)

3 - Gene is cloned

4 - Cells screened transcription/translation of gene protein

-Electrophoresis: separation of DNA fragments  PCR  use in forensics DNA Fingerprint

-Medicines - Vaccines - Gene Therapy - Agriculture (Genetically Modified Organism)

-Human Genome Project -map location of every gene on each chromosome

-Transgenic Animals - human proteins in milk of animals

- Cloning: Differentiated cells used  nucleus removed  next to mammary cell electric shock cell division triggered embryo implanted into surrogate motherexact genetic copy (Ex: Dolly -sheep 1997)

[STEM cells= undifferentiated embryonic cells]