Study guide Chapter 11-12-13-16-17 PDF

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Study guide: Test 3 Chapter 11. Nucleic Acid Structure, DNA Replication, and Chromosome Structure Key points to know about chapter 11 1. What is Nucleotides, Strand, Double helix, Chromosomes or Genome (see the lecture power point or book for more detail). 2. Three different models were proposed for DNA replication which are (1). Semiconservative Model, (2) Conservative Model (3) Dispersive Model: Out of them Semiconservative Model was accepted. A. Semi-conservative replication. According to this model, the two strands of DNA unwind and separate from each other. Then each DNA strand acts as a template (Red in color) (temple is a single DNA stand where polymerase bind and synthesis new complementary strand) and make complementary strand (Blue in color). This replication results in two DNA molecules with one original strand and one new strand (Red and blue in color).

B. Conservative replication. According to this model, DNA replication results in two news DNA stands (double helix). Out of them one DNA molecule has original DNA strands (red color) while another new DNA molecule has exactly the same sequences as the original molecule (this model was not accepted as mechanism of replication could not be explained with satisfaction)

C. Dispersive replication. According to this replication model, DNA replication results in two DNA molecules that are mixtures, or “hybrids,” of parental and daughter DNA. In this model, each individual strand is a patchwork of original and new DNA.

3. Know the steps in DNA replication are required enzymes. 4. Know about Telomeres: Telomers: The tips of eukaryotic chromosomes have specialized repeat of DNA sequence called telomeres. It prevent the loss of genes as chromosome ends wear down.

Telomeres is only present on chromosomes of eukaryotes not in bacterial chromosome) prokaryotic (because eukaryotic chromosomes is linear, have open ends while bacterial chromosome is circular)

5. Know about Chromosome structure and histone protein as well as role of histone protein (Remember, histone proteins are only present in eukaryotes not in prokaryotes)

Chapter 12: Gene Expression at the Molecular Level 1. What is Gene Expression? 2. Know about replication, transcription and translation and their differences. 3. What is central dogma? And its exception.

4. Remember one gene, one polypeptide and protein determine the function (to show its effect protein should have 3D structure: review the protein structure and enzyme-substrate reaction). 5. What is intron and exon? (Remember, introns are only present in eukaryotes not in prokaryotes) 6. Know the steps of transcription. What is the difference in eukaryotes and prokaryotes transcription (don’t be confuse with eukaryotes and prokaryotes replication).

Transcription:

A. Initiation RNA polymerase binds to a sequence of DNA called the promoter. Promoter sequence (part of DNA) is followed by gene (which make mRNA then protein). When RNA polymerase bind, it separate the both the DNA strans and bind to one

DNA strand and use as template. Found near the beginning of a gene. Each gene (or group of co-transcribed genes, in bacteria) has its own promoter. Once bound, RNA polymerase separates the DNA strands, providing the single-stranded template needed for transcription.

B. Elongation. Once RNA polymerase binds, it adds nucleotide (5’ to 3’) in growing RNA strands

C. Termination: Once RNA replication is complete. RNA polymerase separated from DNA Strands. Eukaryotes transcription is controlled by three RNA polymerase (RNA polymerase I, II, and III: read more about their role in book or lecture power point) while prokaryotes have only one RNA polymerase). Know about RNA splicing, mRNA capping and poly A tail and why they are needed.

7. Know the process of translation, codons (including start and stope codons), anti- codons.

Chapter 13: Gene regulation Gene expression is control by extrinsic and intrinsic factors:

Here is the example of extrinsic factor (presence of lactose) which control the gene expression of lactose permeate, a transporter protein and beta galactosidase, which break lactose).

1. Know Operon, Operator, Promoter and gene. Operon: Set of operator (DNA sequence control transcription) and promoter (where RNA polymerase bind) and the structural genes (makes protein through mRNA) they control

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Control of gene expression: Activators increase the rate of transcription: Positive control Repressors inhibit transcription: Negative control

Binding of activator to operator (DNA sequence) allows the RNA polymerase to make mRNA : increases the transcription. Binding of Repressor to operator (DNA sequence) prevent RNA polymerase move and prevent mRNA transcription: reduces the transcription Example of Repressors: Repressor whose default position “ON” or ACTIVE, repressor prevent transcription (lac operon in E coli which make beta galactosidase, beta galactosidase breaks lactose).

When lactose is present, bacterial need beta galactosidase to breaks it. Binding of lactose to repressor, remove it from operator and mRNA transcription for beta galactosidase occure.

Repressor whose default position “OFF” or INACTIVE Tryptophan production (trp opron): Normally bacterial make Tryptophan ( repressor in active), when tryptophan concentration is high bacteria don’t need mote Tryptophan. Tryptophan bind to repressor make it active. Repressor bind to operator and prevent transcription.

Example of Activator: When activator bind to promotor, transcription increases.

2. Transcription in Eukaryotes is different than prokaryotes (review the book or lecture power point). 3. Know about Activators, Repressors, Modulation, Chromatin, DNA Methylation/ acetylation 4. Know about TATA box, Transcriptional start site, Regulatory or response elements, enhancer silence, mediator and transcription factor.

Steps in eukaryotic transcription 1.

TBP (TATA biding proteins bind to TATA box in promoter) after TBP binding, RNA polymerase II bind to TATA box through TBP. 2. Mediator bind to activator, then (mediator-activator) bind to RNA polymerase II. This binding activate RNA polymerase II which make mRNA .

If mediator bind to repressor then transcription stops

3. 4. Know about Epigenetic Gene Regulation (methylation, acetylation) 5. Know about Regulation of RNA Modification and Translation in Eukaryotes

Chapter 16 Simple Patterns of Inheritance 1. What are the Mendel’s Laws of Inheritance (1 and 2) 2. How Chromosome Theory of Inheritance explain/ agree with Mendel’s Laws of Inheritance. 3. Know about Chromosomes, Homologous chromosomes, (Paternal homologous chromosomes, Maternal homologous chromosomes), Gene, Gene locus, Allele (dominant allele/ recessive allele), Auto chromosomes/ Sex Chromosomes. Genotype and Phenotype. 4. What is Punnett square and why we use it (you will be asked few analytical questions about Punnett square use to prepare yourself accordingly) 5. What is Testcross and why we use it. (you will be asked few analytical questions about Testcross use to prepare yourself accordingly). Chapter 17 Complex Patterns of Inheritance (does they follow Mendel’s Laws of Inheritance?) Be familiar with •

Incomplete dominance

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Co-dominance

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Polygenic traits

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Epistasis

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Discrete and Quantitative traits

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Linked gene (what factors affect linked gene separation)

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Genetic mapping

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Extranuclear Inheritance with example...