BIOL 1406 Study Guide - Exam 5

50 flashcards summarizing key concepts from the BIOL 1406 study guide, covering molecular biology, biotechnology, and virology.

What is the structure of DNA according to Watson and Crick?

The double helix model with antiparallel strands and complementary base pairing.

What are the base pairing rules for DNA?

Adenine pairs with Thymine, Guanine pairs with Cytosine.

Define purines in the context of DNA.

Purines are double ring structures that include adenine and guanine.

What are pyrimidines?

Pyrimidines are single ring structures that include cytosine, thymine, and uracil (in RNA).

Describe the semiconservative model of DNA replication.

New DNA consists of one old strand and one new strand.

What enzyme unwinds DNA during replication?

Helicase.

What is the function of DNA polymerase?

Adds nucleotides in the 5' to 3' direction during DNA synthesis.

What does DNA ligase do?

Joins Okazaki fragments on the lagging strand during replication.

What is the difference between leading and lagging strand synthesis?

Leading strand is synthesized continuously, while lagging strand is synthesized in fragments.

What is the role of mRNA?

Carries the genetic message from DNA to the ribosome.

What is the function of tRNA?

Brings amino acids to the ribosome during protein synthesis.

What does rRNA form?

The structural component of ribosomes.

Explain the process of transcription.

Transcription is the process of synthesizing mRNA from DNA, where base pairing involves A with U.

What are promoters in transcription?

They are sequences that signal the start of transcription in DNA.

Define the process of translation.

Translation is the conversion of mRNA into a protein at the ribosomes.

What are codons?

Codons are sequences of three nucleotides on mRNA that correspond to specific amino acids.

What role do anticodons play?

Anticodons are complementary sequences on tRNA that pair with codons on mRNA.

Outline the steps of translation.

Initiation, elongation, termination.

What is RNA interference (RNAi)?

A process where small RNA molecules bind to mRNA, preventing translation.

How is CRISPR-Cas9 utilized in biotechnology?

As a gene editing tool that requires guide RNA and Cas9 enzyme to target specific DNA sequences.

What are SNPs (Single Nucleotide Polymorphisms)?

Variations in a single nucleotide that can influence traits and disease risk.

What is the function of restriction enzymes?

They cut DNA at specific sequences, creating 'sticky ends' for cloning.

What does PCR stand for and what is its purpose?

PCR stands for Polymerase Chain Reaction, and it amplifies DNA sequences.

Why is Taq polymerase important in PCR?

It is heat-stable and allows for DNA amplification during the thermal cycling process.

What is gel electrophoresis used for?

To separate DNA fragments by size.

What are the steps involved in creating recombinant DNA?

1. Isolate gene of interest 2. Cut DNA and plasmid with restriction enzymes 3. Insert gene using ligase 4. Deliver via vector 5. Allow host cells to replicate.

What defines transgenic organisms?

Transgenic organisms contain foreign genes inserted into their genomes.

Provide an example of a transgenic organism.

Fluorescent animals or engineered crops.

What is gene therapy?

A technique that introduces functional genes into patients to treat diseases.

Define proteomics.

The study of all proteins produced in a cell.

Describe the basic structure of a virus.

Composed of DNA or RNA enclosed within a protein capsid, sometimes with an envelope.

What is a lytic cycle?

A viral reproduction cycle that leads to rapid replication and host cell lysis.

Define lysogenic cycle.

A cycle where viral DNA integrates into the host genome and remains dormant.

What must a virus do to infect a host cell?

It must bind to specific receptors on the host cell's surface.

What does latency mean in viral infections?

When a virus remains dormant within a host cell without causing immediate harm.

Explain transduction in virology.

The process where viruses transfer bacterial DNA between cells.

What was the significance of Griffith's experiment?

It provided evidence for transformation in bacteria.

What conclusion did Avery, MacLeod, and McCarty reach?

They determined DNA is the transforming substance responsible for heredity.

How did Hershey and Chase contribute to our understanding of DNA?

They confirmed that DNA, not protein, is the genetic material.

What did Chargaff discover about DNA base pairing?

He established the rules that A pairs with T and G pairs with C.

What was the contribution of Franklin and Wilkins to molecular biology?

They produced X-ray diffraction images that provided insights into the DNA structure.

What are the main types of RNA involved in protein synthesis?

mRNA, tRNA, and rRNA.

List the central dogma of molecular biology.

DNA → RNA → Protein.

What approach can help memorize key concepts and processes in molecular biology?

Using flashcards and diagrams to visualize relationships and functions.