Term
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Definition
| one molecule concerned with transcription |
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Term
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Definition
| region of gene where RNA Polymerase attaches to Transcribe gene |
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Term
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Definition
1. mRNA- carries info from DNA to ribosome
2. rRNA- component of ribosomes
3. tRNA- escorts amino acids to ribosomes |
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Term
| What is the precursor for transcription? |
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Definition
-ribonucleoside triphosphates
-removal of pyrophosphate and polymerization of nucleotide at 3' end |
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Term
| Where does transcription take place? |
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Definition
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Term
| What are the functions of RNA polymerase? |
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Definition
-denatures DNA
-connects opposite DNA strand in 5' to 3' direction |
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Term
| What lines up the opposite DNA template with the RNA? |
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Definition
| Ribonucleoside Triphosphate |
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Term
| What are the different Post-Transcriptional Modifications? |
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Definition
1. addition of a 5' 7 methyl Guanosine cap (mRNA)
2. addition of Poly-A tail (mRNA)
3. Splicing - removal of introns using spliceosomes
4. Primary transcript may be cut into more than one RNA (always occurs in rRNA)
5. the removal of nucleotides from the ends (all RNA)
6. chemical modification of bases (tRNA)
7. addition of CCA to 3' end (tRNA) |
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Term
| What are the functions of the different kinds of RNA? |
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Definition
1. mRNA - carries info
2. tRNA - brings amino acids
3. rRNA - component of ribosomes |
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Term
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Definition
-triplet code: 3 bases in mRNA that code for amino acid
-there are 3 terminator codons (UAA, UAG, UGA)
-AUG is the start codon |
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Term
| Describe the structure of tRNA |
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Definition
-2D shape: 3 leaf clover
-Acceptor stem: amino acid is attached to 3' end
-anticodon loop is across from acceptor stem and pairs with codon in mRNA |
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Term
| Describe Aminoacyl-tRNA Synthase |
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Definition
-load amino onto tRNA using ATP
1. and the specific Amino Acid recognized by that Activating Enzyme
2. specific tRNA recognized by the Synthetase is bound and the Amino Acid transferred from the AMP to the tRNA
3. tRNA, with amino acid, and enzyme are released |
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Term
| What are ribosomes made of and how are the put together? |
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Definition
-large and small subunits made of at least one rRNA and 20-30 proteins
-self assembly: the parts automatically come together |
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Term
| What are the 3 positions ribosomes hold RNA? |
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Definition
1. A site - holds tRNA'
2. P site - holds polypeptide chain
3. E site - holds empty tRNA to exit the ribosome |
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Term
| 1st 3 steps of Translation |
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Definition
1. small ribosomal subunit attaches to 5’ end of mRNA
2. first tRNA attaches to small subunit P Site
3. Large ribosomal subunit attaches to form the complete Ribosome |
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Term
| Where do the first 2 Aminoacyl-tRNAs attach? |
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Definition
1. P site
2. A site, matching 2nd codon of mRNA
*they become adjacent to each other |
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Term
| What catalyzes the peptide bond between the first two amino acids? |
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Definition
Peptidyl Transferase
-transfers the first amino acid from the first tRNA to the second amino acid |
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Term
| What occurs during Translocation? |
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Definition
-moves ribosome to the 3rd codon, with release of first tRNA from E site
-first amino acid is attached to the second, which is attached to the second tRNA |
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Term
| What happens to the 3rd aminoacyl-tRNA anticodon? |
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Definition
| -attaches to the A site of the ribosome according to the 3rd mRNA codon |
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Term
| What happens when a termination codon is reached? |
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Definition
-releasing protein attaches to A site instead of another aminoacyl tRNA
-causes release of the last tRNA and polypeptide
-two ribosomal subunits are released and are recycled to find the same of another mRNA |
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Term
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Definition
| one mRNA and all the ribosomes translating it at the same time |
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Term
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Definition
| first 12-20 hydrophobic amino acids on a glycoprotein |
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Term
| Signal Recognition Particle |
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Definition
| binds to a signal sequence, stops translation, and transport mRNA-ribosome complex to the ER |
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Term
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Definition
-removes the signal sequence, which is not needed for the function of the protein, only as a signal for the transport to the ER
-signal peptide is degraded and oligosaccharide chain is synthesized by ER and attached to protein |
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Term
| Where is the glycoprotein released? |
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Definition
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Term
| What are some Post-Translational Modifications? |
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Definition
1. Proteolysis
2. Glycosylation
3. Phosphorylation |
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Term
Describe the following Mutations
1. Nondisjunction
2. Aneuploidy
3. Polyploidy
4. Duplication
5. Deletion
6. Inversion
7. Translocation |
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Definition
1. chromosomes do not separate
2. occurs when there are not two copies of a chromosome in a diploid cell
3. all chromosomes occur more than twice
4. occurs when a portion of a chromosome is duplicated and inserted
5. portion is removed
6. section is flip 180 degrees
7. moves section to another chromosome |
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Term
| What are the causes of mutations? |
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Definition
1. Ionizing Radiation: X-rays or UV light cut DNA
2. Mutagens: chemically change one base into another; substitution mutation
3. Base Analogues: base is similar enough to be DNA base, but do not always pair with the right base; substitution mutation |
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Term
| What is Mendel's First Law of Segregation? |
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Definition
1. Adults are diploid
2. The two genes segregate one to each gene
3. Fertilization restores the diploid number |
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Term
| What is Mendel's Second Law of Independent Assortment? |
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Definition
| Alleles of different genes will assort into gametes independently of one another |
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