BIO 400 Exam 3 A+ Pass Verified

BIO 400 Exam 3 A+ Pass Verified Telomeres - Answer- Repeated DNA sequences at the ends of eukaryotic chromosomes. (Pages at the end of the recipe book that are not missed) Telomerase - Answer- An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells. stem cells - Answer- unspecialized cells that retain the ability to become a wide variety of specialized cells DNA pol III - Answer- Using parental DNA as a template, synthesizes new DNA strand by adding nucleotides to an RNA primer or a pre-existing DNA strand DNA pol I - Answer- Removes RNA nucleotides of primer from 5' end and replaces them with DNA nucleotides Interons - Answer- do not code for proteins, separate exons, get spliced out of eukaryotes after transcription exons - Answer- Coding segments of eukaryotic DNA. what happens if you run out of telomeres - Answer- stop dividing or apoptosis gene expression - Answer- DNA --- RNA --- Proteins through translation and transcription Transcription - Answer- synthesis of an RNA molecule from a DNA template. Initiation, elongation, and termination Translation - Answer- Process by which mRNA is decoded and a protein is produced where is the best place to regulate gene expression - Answer- at the initiation step of transcription Gene - Answer- A segment of DNA on a chromosome that codes for a specific trait initiation of transcription - Answer- Attachment of RNA polymerase to the promoter RNA polymerase binds to a promoter start (start!) elongation (transcription) - Answer- RNA polymerase unzips the DNA and assembles RNA nucleotides using one strand of DNA as a template. creates the corresponding strand going from the 3' to 5' end of DNA, thus creating a 5' to 3' new mRNA strand. (MUST MAKE THE STRAND 5'--- 3') Termination of transcription - Answer- RNA polymerase reaches a terminator sequence (Stop codon) and detaches from the template, leaving a new strand of mRNA to leave the Nucleus promoter - Answer- region of DNA that indicates to an enzyme where to bind to make RNA ( NOT A PART OF THE GENE) 5' end and 3' end - Answer- 5' end - has a 5' carbon attached to a phosphate 3' end - has a 3' carbon attached to a hydroxyl group difference between DNA and RNA - Answer- RNA is derived from DNA by transcription. Contains Ribose sugar component. Uracil instead of Thymine making the rna mature - Answer- 1. splicing 2. capping 3. tail Splicing RNA - Answer- spliceosomes cut out introns poly-A tail - Answer- Modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides. longer the tail then more prolonged the protein is 5' cap - Answer- The 5' end of a pre-mRNA molecule modified by the addition of a cap of guanine nucleotide. initiation of translation - Answer- small ribosomal subunit attaches to 5' end of mRNA and scans the mRNA to find the first AUG codon where the tRNA is waiting. large ribosomal subunit comes in and the trna goes to the P site and codes for Met elongation (translation) - Answer- new tRNA comes in with the anticodon corresponding to the next codon. the amino acids are bonded with a peptide bond then the tRNA in the P site moves to the exit site (E) and is kicked off, leaving the Met behind. The ribosome moves down one codon and the process repeats termination of translation - Answer- occurs when a stop codon in the mRNA reaches the A site of the ribosome nonsense mutation - Answer- subsitution of wrong nucleotide into DNA that produces an early stop codon missense mutation - Answer- A base-pair substitution that results in a codon that codes for a different amino acid. Glycolysis - Answer- the breakdown of glucose by enzymes, releasing energy and pyruvic acid. where does oxygen get converted to water - Answer- ox phos what is produced by oxidative phosphorylation - Answer- ATP, NAD+, FAD+, and water Chemiosmosis - Answer- A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme. Light Independent Reactions (Calvin Cycle) - Answer- set of reactions in photosynthesis that do not require light; energy from ATP and NADPH is used to build high-energy compounds such as sugar; also called the Calvin cycle occurs in the stroma Leading Strand vs. Lagging Strand - Answer- works toward replication fork / works away from replication fork; both always move in the 5' 3' direction why did Hershey and chase choose P and S isotopes - Answer- DNA had P but not S, and proteins have S but not P Hershey-Chase Experiment - Answer- Used radioactive material to label DNA and protein; infected bacteria passed on DNA; helped prove that DNA is genetic material not proteins Dispersive DNA model - Answer- Each strand of the resulting DNA have both new and old DNA Conservative DNA model - Answer- Both parental strands stay together after DNA replication semi-conservative model - Answer- Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand. what bonds have the highest energy - Answer- hydrocarbons (C-H), lots of potential energy because there is equal electronegativity thus, electrons are further from the Nucleus-- more potential energy which macromolecule has the highest energy and why? - Answer- fats (most hydrocarbons) oxidation - Answer- loss of electrons reduction - Answer- gain of electrons Oxioreductases - Answer- catalyze oxidation-reduction reactions