Micro Exam 2 – Flashcards
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Genotype |
The genetic makeup of an organism |
Phenotype |
observable characteristics or traits of an organism |
genome |
entire hereditary information of an organism |
Chromosome |
organized structure of DNA, protein and RNA found in cells. Chromosomes contain the genes. |
Name 4 things about DNA |
•Polymer of nucleotides: Adenine, thymine, cytosine, and guanine •Double helix associated with proteins •"Backbone" is deoxyribose-phosphate •Strands are held together by hydrogen bonds between AT and CG
•Strands are antiparallel |
Name 4 things about Translation |
•mRNA is translated in codons (three nucleotides) •Translation of mRNA begins at the start codon: AUG •Translation ends at nonsense (stop) codons: UAA, UAG, UGA
•Open reading frame |
______ sense codons on mRNA encode the ____ amino acids |
61, 20 |
Anticodon |
The 3 nucleotides by which a tRNA recognizes an mRNA codon [image] |
If an amino acid can be coded for by more than one codon it is: |
degenerate |
3 steps of translation |
•Initiation (Formylmethionine in prokaryotes and methionine in eukaryotes) •Elongation •Termination [image] |
Genomics |
study of genomes |
Gene |
molecular unit of heredity of a living organism |
Bioinformatics |
the science of collecting and analyzing complex biological data such as genetic codes |
Semi conservative replication
|
produce to copies such that ach contained one of the original strands and one new strand |
Codon |
three nucleotides coding for specific amino acid |
Name 3 things about Epigenetic control |
–Methylating nucleotides –Methylated (off) genes are passed to offspring cells
–Not permanent |
Operon |
It is comprised of an operator and a promoter and one or more structural genes that it controls [image]
|
Mutation |
change in the DNA (gene or chromosome)
Mutations may be neutral, beneficial, or harmful |
Silent Mutation |
change in DNA sequence that cause no effect |
Missense Mutation |
a point mutation where the change of one nucleotide causes the coding of a different codon |
Spontaneous mutations |
Occur in the absence of a mutagen |
Mutagen |
Agent that causes mutations |
A Base substitution is the same as |
a point substitution |
Nonsense mutation |
Stop codon |
How one can determine the relatedness between two or more organisms |
By doing bioinformatics analysis on sequences (Is this the right answer?) |
Which organism is NOT correctly matched to its energy source? A.Chemoheterotroph - glucose B.Chemoautotroph-NH3 C.Photoheterotroph – light D.Chemoautotroph - Fe2+ E.Photoautotroph - CO2 |
E.Photoautotroph - CO2 |
What is the “Central Dogma”? How does genetic information get transferred in biological systems? What enzymes are involved? What are their functions? |
DNA > RNA> Protein Photolase, primase, ribozyme, RNA polymerase, snRNP, topoisomerase, transposase, DNA Gyrase, DNA ligase, DNA polymerase, endonuclease, exonuclease, helicase, mythylase |
Photolyase |
Uses visible light energy to seperate UV induced pyrimidine dimers |
Primase |
Makes RNA primers from a DNA template |
Ribozyme |
RNA enzyme that removes introns andsplices exons together [image] |
RNA Polymerase |
Copies RNA from a DNA template |
snRNP |
RNA protein complex that removes introns and splices exons together (how is this different from a robozyme?) SnRNPs (pronounced "snurps"), or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs. A ribozyme is an RNA molecule with a well defined tertiary structure that enables it to perform a chemical reaction. |
Topoisomerase |
Relaxes supercoiling ahead of the replication fork; seperates DNA circles at the end of DNA replication [image] [image]
|
Transposase |
Cuts DNA backbone leaving single-stranded "sticky-ends" [image] |
DNA Gyrase |
Relaxes supercoiling ahead of the replication fork
(Topoisomerase vs DNA gyrase) |
DNA Ligase |
Makes covalent bonds to join DNA strands; joins Okazaki fragments and new segments in excision repair |
DNA Polymerase |
Synthesizes DNA; proofreads and repairs DNA |
Endonucleases |
Cut DNA backbone in a strand of DNA; fascilitate repair and insertions |
Exonucleases |
Cut DNA from an exposed endof DNA; facilitate repair |
Helicase |
unwinds double stranded DNA [image] |
Methylase |
Adds methyl group to selected bases in newly made DNA |
Describe the processes of DNA replication, transcription and translation |
a. Replication – DNA to DNA b. Transcription – DNA to RNA
c. Translation – RNA to protein |
Compare and contrast transcription and translation processes between prokaryotes and ?eukaryotes. What differences are due to different cell structures? |
Prokaryote – polycistronic, absence of 7 cap, no poly(A) tail (polycistronic a single mRNA encoding several different polypeptide chains.)
Eukaryote – monocistronic presence 7 cap, with poly(A) tail (monocistronic Referring to fully processed mRNA that codes for a single protein.) |
What is the genetic code? Why is the genetic code described as degenerate? |
61 sense codons 20 amino acids. Because an amino acid can be coded by more than one codon. |
What is the function of the start codon? Know its sequence. |
Where translation starts on mRNA, AUG |
What are stop codons? How many are there? Know their sequence. |
Where translation ends UAA, UAG, UGA |
What is the role of the promoter, terminator and mRNA in transcription |
Promoter regulates the binding of RNA polymerase and the rate at which RNA is transcribed. Terminator signals end of transcription. mRNA is made during transcription |
Plasmid |
A linear or circular double-stranded DNA that is capable of replicating independently of the chromosomal DNA. Certain plasmids are able to insert themselves into the chromosomes particularly in regions where there is a common sequence of nucleotides. Hence, they are used in recombinant DNA technology and research as means for transferring genes between cells or as cloning vectors. |
Transposon |
segments of DNA that can move from one region of DNA to another |
