MOL - Molecular Genetics [OVERVIEW]
Molecular Genetics
Introduction
Nucleic acids, and DNA in particular, are key macromolecules for the continuity of life. DNA bears the hereditary information that’s passed on from parents to children, providing instructions for how (and when) to make the many proteins needed to build and maintain functioning cells, tissues, and organisms.
In this module, you will continue with the study of genetics by further examining the structures and functions of nucleic acids in gene expression. The processes that lead to gene expression include replication, transcription, and translation to result in protein synthesis. Regulation of gene expression and cell specialization is important for the continuation of populations and the survival of individuals. The module will also cover aspects of biotechnology and types of mutations that occur and result in changes to proteins and phenotype.
List of Lessons
In this module, we will study the following topics:
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- DNA/RNA Structure – in this lesson, you will learn the structure of both DNA and RNA and how they differ.
- Replication – in this lesson, you will learn how and why DNA replication occurs.
- Transcription – in this lesson, you will learn about step 1 of protein synthesis which includes transcription and RNA processing in eukaryotes.
- Translation – in this lesson, you will learn about step 2 of protein synthesis which is translation of the mRNA into a protein.
- Mutations – in this lesson, you will learn about errors in replication that lead to mutation and the results of those mutations.
- Regulation – in this lesson, you will learn about prokaryotic and eukaryotic regulation of gene expression.
- Gene Technology – in this lesson, you will learn about different laboratory techniques used to transfer DNA between organisms.
- Development – in this lesson, you will learn about the mechanisms that affect the way our traits are expressed.
Module Objectives
By the end of this module, students will be able to:
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- Describe the structures involved in passing hereditary information from one generation to the next.
- Describe the characteristics of DNA that allow it to be used as the hereditary material.
- Describe the mechanisms by which genetic information is copied for transmission between generations.
- Describe the mechanisms by which genetic information flows from DNA to RNA to protein.
- Explain how the phenotype of an organism is determined by its genotype.
- Describe the types of interactions that regulate gene expression.
- Explain how the location of regulatory sequences relates to their function.
- Explain how the binding of transcription factors to promoter regions affects gene expression and/or the phenotype of the organism.
- Explain the connection between the regulation of gene expression and phenotypic differences in cells and organisms.
- Describe the various types of mutation.
- Explain how changes in genotype may result in changes in phenotype.
- Explain how alterations in DNA sequences contribute to variation that can be subject to natural selection.
- Explain the use of genetic engineering techniques in analyzing or manipulating DNA.
Key Terms
Amino Acid - molecules containing an amine group, a carboxylic acid group, and a specific side‐chain group.
Anticodon - unit made up of three nucleotides that correspond to the three bases of the codon on the mRNA.
Bacteriophage - any one of a number of viruses that infect bacteria.
Biotechnology - a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, and medicine.
Cloning - the process of producing similar populations of genetically identical individuals asexually.
Codon - a series of three adjacent bases in one polynucleotide chain of a DNA or RNA molecule.
Deletion - mutation in which a part of a chromosome or a sequence of DNA is missing.
Deoxyribonucleic acid - is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms.
Deoxyribose – monosaccharide found in DNA.
DNA Fingerprinting - a test to identify and evaluate the genetic information of individuals' DNA ligase - joins the sugar-phosphate backbones of all fragments into one continuous strand.
DNA polymerase - attaches free nucleotides to open complementary positions.
Gel Electrophoresis - a technique used in the laboratory that results in the separation of charged molecules.
Gene Expression - the process by which information from a gene is used in the synthesis of a functional gene product.
Genetic Engineering - manipulation of an organism's genome using modern DNA technology.
Helicase - unwinds parental double helix at replication forks.
Insertion - the addition of one or more nucleotide base pairs into a DNA sequence.
mRNA - a molecule of RNA that encodes a chemical "blueprint" for a protein product.
Mutation - changes in a genomic sequence in such a way as to alter the genetic message carried by that gene.
Nucleotide - molecules that, when joined together, make up the structural units of RNA and DNA.
Phosphate Group - functional group of one central phosphorus atom surrounded by four oxygen atoms.
Point Mutation - single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide.
Polymerase Chain Reaction - a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA.
Primase - creates an RNA primer at the 5' end of leading strand and fragments of lagging strand.
Protein Synthesis - process by which proteins are assembled from amino acids based on blueprints encoded in DNA; transcription and translation.
Recombinant DNA - DNA created by inserting parts of one DNA strand into another.
Restriction Enzymes - DNA‐cutting enzymes found in bacteria, used to cut DNA fragments at specific sequences.
Ribonucleic Acid - a biologically important type of molecule that consists of a long single strand of nucleotide units.
Ribose - an organic compound, monosaccharide found in RNA.
RNA polymerase - enzyme which uses one strand of DNA as a template or model which guides the synthesis of RNA.
rRNA - ribosomal ribonucleic acid, RNA component of the ribosome.
Semiconservative - the normal process of DNA synthesis, in which the two original strands of the molecule separate and new complementary strands are added to each parent.
Start Codon - the sequence at which a ribosome begins to translate RNA into a polypeptide.
Stop Codon - the sequence at which a ribosome ends translation of RNA into a polypeptide.
Substitution - single base mutations in which one nucleotide is replaced with another.
Topoisomerase - relieves over winding strain ahead of replication fork.
Transcription - the process of creating a complementary RNA copy from DNA.
Transformation - one of several processes by which genetic material in the form of "naked" DNA is transferred between microbial cells.
Translation - third stage of protein synthesis; family of tRNA molecules enables the codons in an mRNA molecule to be translated into the sequence of amino acids in the protein.
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