BACE EXAM

plasmid DNA?

small, circular, double-stranded DNA that can replicate independently of chromosomal DNA. It often carries genes that provide resistance to antibiotics and can be used in genetic engineering.

Chromosomal DNA

is the structured DNA found in the chromosomes of cells; it contains the genetic information necessary for the growth, development, and reproduction of organisms and is linear in structure in eukaryotes.

Prokaryotic DNA

typically circular, double-stranded, and not associated with histones. It is found in the nucleoid region of prokaryotic cells and can include plasmids.

Protein structure levels

primary (sequence of amino acids)

secondary (folding into alpha helices and beta sheets)

tertiary (3D folding due to side chain interactions)

quaternary (assembly of multiple polypeptide chains).

central dogma

the flow of genetic information from DNA to RNA to protein. It involves two key processes: transcription (where DNA is converted to messenger RNA (mRNA) and involves the use of ribosomal RNA (rRNA) and transfer RNA (tRNA) in translation) and translation (where mRNA is decoded by ribosomes to synthesize a specific polypeptide chain, with the assistance of tRNA, which carries amino acids to the ribosome).

How enzymes work

catalysts that increase the rate of chemical reactions by lowering the activation energy required for the reaction to proceed. This allows reactions to occur more quickly and efficiently.

Protease

Degrades proteins

Restriction enzymes

Digests DNA

What are the roles of major cell organelles?

nucleus (houses DNA),

mitochondria (produces energy),

endoplasmic reticulum (synthesizes proteins and lipids),

Golgi apparatus (modifies and packages proteins),

lysosomes (digests waste)

ribosomes (sites of protein synthesis).

Bacterial plasmids

contain antibiotic resistance genes, replication origins, and specific sequences for cloning, making them valuable for growth selection in genetic engineering. Markers commonly used for bacterial growth include genes that confer resistance to antibiotics such as ampicillin or kanamycin, allowing for the selective growth of transformed bacteria that carry the plasmid.

Steps of generating monoclonal antibodies

1. Immunization: Introducing an antigen to stimulate an immune response.

2. Cell Fusion: Merging B-cells with myeloma cells to create hybridomas.

3. Screening: Identifying hybridomas that produce the desired antibody.

4. Cloning: Expanding the selected hybridomas to produce large quantities of antibodies.

5. Harvesting: Collecting and purifying the monoclonal antibodies for use.

   In Chicken Fingers Sauce Causes Hunger

Pros and cons of vaccine types

Pros: 1. Live Attenuated Vaccines: Strong immune response, long-lasting immunity. 2. Inactivated Vaccines: Safe, stable storage, no risk of disease. 3. Subunit, Recombinant, & Conjugate Vaccines: Targeted immune response, fewer side effects.

Cons: 1. Live Attenuated Vaccines: Risk for immunocompromised individuals. 2. Inactivated Vaccines: Weaker immune response, often require boosters. 3. Subunit, Recombinant, & Conjugate Vaccines: Higher production costs, potential for incomplete immunity.

Light Microscopes

visible light to illuminate specimens.

They have several key attributes: relatively low cost, ease of use, the ability to observe live samples, and high-resolution capabilities for magnifications up to 1000x.

They are best used for viewing cellular structures, tissues, and organisms that are transparent or thin.

Transmission electron microscope

use a beam of electrons to view thin specimens at high resolution.

They provide very detailed images, allowing for the observation of internal structures at the nanometer scale.

are best used for studying the ultrastructure of cells, organelles, viruses, and materials.

Scanning electron microscopes

focused beam of electrons across a specimen's surface, providing high-resolution, three-dimensional images.

They have a greater depth of field than light microscopes and are best used for examining the surface topography and composition of materials, including biological specimens and non-biological samples.

steps of SDS-PAGE

1. Sample Preparation: Proteins are denatured and coated with SDS to impart a negative charge.

2. 2. Gel Electrophoresis: Samples are loaded into a gel and subjected to an electric field, causing proteins to migrate based on size.

3. Staining: Proteins in the gel are stained to visualize separated bands. SDS-PAGE is performed to analyze protein size, purity, and to isolate specific proteins for further study.

Aseptic technique

practices employed to prevent contamination of sterile environments and maintain the integrity of samples while working in laboratories. This includes sterilizing equipment, using gloves, masks, and proper disposal of waste to ensure a contaminant-free workspace.

Spectrometer Levels for Different Molecules

molecules based on their interaction with electromagnetic radiation, revealing information about their structure and composition.

Key levels include:

1. Ultraviolet/Visible Spectroscopy (UV-Vis) for electronic transitions in organic compounds.

2. Infrared Spectroscopy (IR) for molecular vibrations and functional groups identification.

3. Nuclear Magnetic Resonance (NMR) for determining molecular structure via magnetic properties of nuclei.

600 nm spectrometer

Bacteria cells

280nm spectrometer

Most proteins

260nm spectrometer

DNA

DNA extraction and PCR

1. Extract DNA from cell

2. Add reagent needed for PCR to DNA in small PCR tube

3. Place tube in thermal cycler

4. Denature - heights heat separates strand

   anneal -lowest heat adds primers

   extension - medium heat builds DNA

5. Analyze results using electrophoresis

Types of reagents

1. DNA Template: The target DNA to be amplified.

2. DNA Polymerase: Enzyme that synthesizes new DNA strands.

3. Primers: Short sequences of nucleotides that initiate DNA synthesis.

4. Nucleotide Triphosphates (dNTPs): Building blocks of DNA (adenine, thymine, cytosine, guanine).

5. Buffer: Maintains optimal pH and provides necessary salts for enzyme activity.

ELISA

technique used to detect and quantify proteins, antibodies, or hormones in a sample, commonly employed in diagnostics, research, and quality control.

Restriction enzymes

are proteins that digest DNA at specific recognition sites, allowing for the manipulation and analysis of genetic material in research and biotechnology.

genetic engineering protocol

includes the following steps:

1. DNA extraction from the source organism.

2 Gene of interest identification and amplification through PCR.

3 Insertion of the gene into a plasmid vector.

4 Transformation of host cells with the recombinant plasmid.

5. Selection of successfully transformed cells and analysis of gene expression.

Chemically competent cells

are bacterial cells that can take up external DNA through chemical treatments, typically made permeable to DNA by a process that often involves calcium chloride. They facilitate transformation with high efficiency, are used in molecular cloning, and usually require heat shock for DNA uptake.

Properties of agar gel

gelatinous substance derived from red algae, used as a solidifying agent in microbiological culture media. It has properties such as being non-toxic, stable at a wide range of temperatures, and providing a surface for bacterial growth. Agar gel is also used to support the diffusion of nutrients and can be modified for various applications in laboratories.

How does voltage effect gel electrophoresis

, increasing the voltage can accelerate the movement of DNA or proteins through the gel, leading to faster separation.

However, excessive voltage may cause overheating and result in poor resolution or distortion of bands.

Optimal voltage settings are crucial for achieving clear, distinct results.

negative control

is a sample or experimental condition that lacks the specific treatment or factor being tested, ensuring that any observed effects in the experimental group can be attributed to the treatment. It helps identify false positives and validates the experimental results.

Principal Component Analysis (PCA)

is a statistical technique used to reduce the dimensionality of data by transforming it into a new set of uncorrelated variables called principal components, which capture the most variance in the data. This method is widely used in data analysis and machine learning for simplifying complex datasets while retaining their essential features.

Quality control vs. quality assurance

Quality Control (QC) involves the operational techniques and activities used to fulfill requirements for quality. It focuses on identifying defects in the finished product. Quality Assurance (QA) is a systematic process that ensures quality in the development and production processes, aiming to improve and prevent defects by focusing on the processes used to create the product.

What is upstream processing?

refers to the initial stages of bioprocessing, where raw materials are prepared and biological organisms, such as cells or microorganisms, are cultured and nurtured to produce desired products, like proteins or enzymes. This stage includes media preparation, inoculation, and fermentation.