BIO110- Chapter 6

BIO110- Chapter 6

Chapter Outline

What is DNA?

Gene Expression

Mutations

Genetic Engineering

What is DNA?

• Deoxyribonucleic acid

• What is the significance of DNA? What does it do in a cell? (genes!)

• Structure of DNA: Made of nucleotides – (which has 3 parts) 1. Sugar (deoxyribose) 2. Phosphate group (has a negative charge) 3. Nitrogen containing base (a. Adenine (A) b. Guanine (G) c. Cytosine (C) d. Thymine (T)) i. Nitrogen bases have base pairing rules 1. A-T 2. C-G

DNA Replication

• DNA replication – making a copy of DNA from an existing DNA strand How is it done?

• 1. Double helix is peeled apart (unzipped)

• 2. New strands are made using existing strands as templates a. Follows base pairing rules b. DNA polymerase is the enzyme that reads DNA and makes new strands

• 3. DNA fragments are fused together to make two new strands DNA replication is semi-conservative – one “old” strand is fused with one “new” strand

Comparing DNA and RNA

• i. How many strands?

• ii. What are the bases?

• iii. What is the function?

Multiple Select

Select the correct pairs

• A-A

• A-T

• C-G

• T-A

Multiple Choice

During DNA Replication, which enzyme adds new nucleotides to the newly synthesized DNA strand?

• Helicase

• DNA Ligase

• DNA Polymerase

• RNA Polymerase

The Central Dogma (the flow of genetic information)

• DNA → RNA → Protein

• DNA Replication, Transcription, Translation

Transcription

• Transcription – DNA is used to make messenger RNA (mRNA), which contains a copy of the information in DNA

• 1. Occurs in the nucleus

• 2. How does it occur?

• 3. What enzymes/molecules are involved?

• 4. What is a codon?

Translation

• Translation – information in mRNA is translated into amino acid sequence to make proteins

• 1. Occurs in the cytoplasm

• 2. What is the function of ribosomes in translation? a. What is ribosomal RNA (rRNA)?

• 3. What is the function of transfer RNA (tRNA) in translation?

• 4. Be sure to know how to use a genetic code

• 5. 3 steps – what happens during each? a. Initiation b. Elongation c. Termination

Multiple Choice

Where does transcription occur?

• Cytoplasm

• Nucleus

• ER

• Ribosomes

Multiple Choice

What does the codon UGG code for?

• Stop

• Trp

• Arg

• Cys

Multiple Choice

What does the codon AUG code for?

• Met

• Ile

• Thr

• Ser

Multiple Choice

What does the codon UGA code for?

• Cys

• Stop

• Trp

• Arg

Gene Expression- What is it?

• a. What is the importance of gene regulation?

• i. Types of gene regulation 1. X chromosome inactivation 2. Transcription factors 3. Control of RNA – introns vs exons 4. Protein control

• b. What is signal transduction? i. What are homeotic genes?

Mutations – changes in DNA

• a. Are mutations bad?

• b. How do they occur? – Mutagens

• c. What are the different types of mutations? i. Point mutation 1. silent 2. missense 3. Nonsense ii. Frameshift mutation 1. Deletion 2. Insertion

Open Ended

Explain why or why not mutations are always bad

Open Ended

Give an example of an environmental mutagen

Multiple Choice

Silent, nonsense, and missense mutations are all:

• point mutations

• frameshift mutations

Multiple Choice

_____________ mutations often result in different or defective proteins.

• point

• frameshift

What is cancer?

• How is cancer controlled? 1. Proto-oncogenes – what happens when they are mutated? 2. Growth factors 3. Tumor suppressor genes

• How does cancer progress?

• How can you prevent cancer?

• If diagnosed with cancer, what are your treatment options?

Genetic engineering – what can we do with DNA?

• a. Cloning

• b. Biotechnology

• c. Restriction enzymes – what are they? How do we use them?

• d. Genomic libraries – why are they important?

• e. Nucleic acid probes

• f. DNA synthesis

• g. Complementary DNA (cDNA) h. And More!!

Genetically modified organisms (GMOs) and transgenic organisms

• i. How is this possible?

• ii. What are some safety and ethical concerns?

Open Ended

When you hear "GMO" what are some things you have heard?

Polymerase chain reaction (PCR)

• i. How is this done? To what purpose?

• Why is our great state of North Carolina relevant?

DNA profiling

• i. Short tandem repeats (STR) and STR analysis – significance?

• ii. Gel electrophoresis

Human Genome Project – what is the significance?

• i. Why did we do it?

• What were some ethical dilemmas with the HGP?

Gene therapy

• i. How is it done?

• ii. Why is it done?

Summary/What to Study

What is DNA? (basics, replication, central dogma, transcription, translation)

Gene Expression (what it is & where is can happen)

Mutations (types, cancer, etc)

Genetic Engineering (different types and details about each type & its use in the real world)