Hey guys Thanks for purchasing this study guide First and foremost this is how I would study for this final I wrote down the answers for the first third and fourth study guide because I figured this would be the most effective way of getting all the detailed information across and understandable I also added additional information that I found helpful or important The study guide questions can be found online on blackboard I didn t put them on here to conserve paper For unit II I wrote important facts and definitions based from the study guides powerpoints and the book REMEMBER It is a cumulative final based off previous tests practice tests and questions we ve seen throughout the semester so definitely go through all the powerpoints quizzes exams and practice exams on blackboard This guide is just to help you keep all the information more concise and available rather than having to search through slides If you don t understand a term make a note card with the definition Trust me it will help a lot And if you are having troubles with any specific section try to find it in the book and read that section Happy studying and good luck on the final Unit 1 Study Guide 1 DNA is the genetic material in a double helix structure Each strand is made of a linear sequence of nucleotides Nucleotides are made of a phosphate group a 5 carbon sugar and a nitrogenous base A T G and C Messenger RNA or mRNA is a type of RNA that is transcribed from DNA RNA is single stranded and is similar to a DNA molecule because it uses a linear nucleotide sequence The nucleotide bases are made of a phosphate a sugar called ribose deoxyribose in DNA and nitrogenous base Uracil instead of Thymine the rest are identical to DNA Specifically mRNA has been transcribed off a gene and is sent from the nucleus into the cytoplasm so it can be decoded into a specific protein at a ribosome in the cytoplasm A protein is made from a polypeptide chain of 3 mRNA bases called a codon One codon codes for a specific protein amino acids Replication occurs in the nucleus of the cell and DNA must be copied exactly before cells divide DNA polymerase is required to add nucleotides to the growing strand on the 3 end of the new DNA strand The two strands are separated and serve as the parental strand for the new strand Each new molecule of DNA has one old strand and one new one a concept known as semi conservative Transcription also occurs in the nucleus Transcription happens when mRNA is transcribed off a specific gene RNA polymerase separates the DNA strands and one of the two strands serves as a template strand A new strand is created by the matching up of nucleotides to the template strand After the strand is terminated it is transported from the nucleus to the cytoplasm for translation Translation occurs in the cytoplasm of the cells Ribosomal subunits assemble to process the mRNA strand into polypeptide chains or proteins Ribosomes and tRNA are used in translation which occurs in the cytoplasm Ribosomal subunits assemble in the cytoplasm to process strands of mRNA into proteins The correct tRNA molecule binds to the mRNA tRNA molecules are a kind of RNA that interprets the codons from mRNA from its own anticodons and recognizes them to make amino acids There are two tRNAs in a ribosomal unit at a time and help to make a polypeptide chain to be exported out of the ribosomal unit The genetic code means that there are specific triplets of nucleotides that code for one amino acid These triplets are called codons Anticodons are triplet nucleotides at one end of the tRNA that recognizes a particular codon on an mRNA molecule A mutation is a change in the genetic material of the cell Small scale mutations are called point mutations which are a change in one nucleotide in a gene It could be a substitution addition or deletion An addition or deletion could change the reading frame of the nucleotides Mutations are important to the cell organism because they can be small scale or large scale in changing the genetic code A gene is a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA Genetic info is stored in the sequence of nucleotides A chromosome is a structural unit of 1 long strand of double helical DNA molecule and bound proteins The DNA is packed in multiple ways to make a chromosome located in the cell s nucleus Chromatin is a complex of DNA and proteins that makes up a eukaryotic chromosome It s a mass of very long thin fibers Heterochromatin is the tightly packed chromatin that is not exposed to be used genetically It is involved in regulating genes because if it isn t exposed a gene cannot be expressed Euchromatin is the exposed chromatic that is loosely packed It is exposed so it can be replicated or expressed Control elements are segments of non coding DNA that helps regulate a transcription factor The control elements help to determine which genes get expressed The enhancer made in a cell is made up of 3 control elements and only certain activators are available in the cell to bind to the control elements that which will make a transcription initiation complex to begin transcription 2 Differential gene expression refers to the gene regulation that determines which cell or type of cell a cell is going to be specialized into Genes are regulated from the chromosomal level all the way down to the post translational level Gene regulation simply means the control of gene expression Gene expression is controlled generally at the transcription level Transcription factors the specific particulars TFs in a cell determine which genes are expressed in different cell types They specifically influence RNA polymerase to modulate the amount of transcription Binds to DNA and affects transcription of genes Control elements a segment of non coding DNA that helps regulate transcription of a gene by binding a transcription factor Multiple are found in the gene s enhancer Histone Acetylation modification of histone proteins by the addition of acetyl group exposed DNA by weakening histone association with DNA making it accessible DNA methylation addition of methyl groups to the cytosine and guanine nucleotides which makes DNA physically inaccessible to express is reversible 3 other ways genes are regulated 1 Not all mRNA is translated 5 cap and a 3 A tail are added and determined if a transcript will even get exported to the cytoplasm to be expressed 2 microRNA binds to mRNA and block ribosome from translating
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