Shared Flashcard Set

Details

Biology Lecture 9
Chapter 17
37
Biology
Undergraduate 1
02/16/2011

Additional Biology Flashcards

 


 

Cards

Term
Nucleotide Sequence
Definition
The order in which [[ nucleotides are situated in a chain relative to one another, which in future will provide the template of a particular [[amino acid, therefore making the order of the nucleotide sequence important.
Term
RNA polymerase
Definition
A polymerase that catalyzes the synthesis of a complementary strand of RNA from a DNA template, or, in some viruses, from an RNA template.
Term
Uracil
Definition
A pyrimidine base, C4H4N2O2, that is an essential constituent of RNA.
Term
Promoter
Definition
a region of DNA that facilitates the transcription of a particular gene.
Term
Terminator-RNA synthesis
Definition
sequence of nucleotides in DNA that marks the end of a gene and signals RNA polymerase to release newly made RNA
Term
Initiation-RNA synthesis
Definition
two ribosomal subunits link onto the mRNA
Term
Elongation-RNA synthesis
Definition
successive amino acids are added to the growing chain, brought in by transfer RNAs
Term
Termination-RNA synthesis
Definition
end of DNA gene, beginning of RNA molecure
Term
RNA transcript
Definition
from DNA to RNA,
process of creating a complementary RNA copy of a sequence of DNA.[1] Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes. During transcription, a DNA sequence is read by RNA polymerase, which produces a complementary, antiparallel RNA strand. As opposed to DNA replication, transcription results in an RNA complement that includes uracil (U) in all instances where thymine (T) would have occurred in a DNA complement.
Term
Transcription
Definition
process of creating a complementary RNA copy of a sequence of DNA.[1] Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes. During transcription, a DNA sequence is read by RNA polymerase, which produces a complementary, antiparallel RNA strand. As opposed to DNA replication, transcription results in an RNA complement that includes uracil (U) in all instances where thymine (T) would have occurred in a DNA complement.
Term
Translation
Definition
third stage of protein biosynthesis (part of the overall process of gene expression). In translation, messenger RNA (mRNA) produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein. In Bacteria, translation occurs in the cell's cytoplasm, where the large and small subunits of the ribosome are located, and bind to the mRNA. In Eukaryotes, translation occurs across the membrane of the endoplasmic reticulum in a process called vectorial synthesis. The ribosome facilitates decoding by inducing the binding of tRNAs with complementary anticodon sequences to that of the mRNA. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA passes through and is "read" by the ribosome in a fashion reminiscent to that of a stock ticker and ticker tape.
Term
Triplet Code
Definition
set of 2 nucleotide long words that specify the amino acids for polypeptide chains
Term
Codon
Definition
A sequence of three adjacent nucleotides constituting the genetic code that determines the insertion of a specific amino acid in a polypeptide chain during protein synthesis or the signal to stop protein synthesis.

[COD(E) + -ON1.]
Term
mRNA
Definition
a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes. Here, the nucleic acid polymer is translated into a polymer of amino acids: a protein. In mRNA as in DNA, genetic information is encoded in the sequence of nucleotides arranged into codons consisting of three bases each.
Term
tRNA
Definition
small RNA molecule (usually about 73-95 nucleotides[citation needed] ) that transfers a specific active amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. It has a 3' terminal site for amino acid attachment. This covalent linkage is catalyzed by an aminoacyl tRNA synthetase. It also contains a three base region called the anticodon that can base pair to the corresponding three base codon region on mRNA. Each type of tRNA molecule can be attached to only one type of amino acid, but because the genetic code contains multiple codons that specify the same amino acid, tRNA molecules bearing different anticodons may also carry the same amino acid.
Term
rRNA
Definition
is the RNA component of the ribosome, the organelle that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity. The tRNAs bring the necessary amino acids corresponding to the appropriate mRNA codon.
Term
ribosome-large and small units
Definition
Ribosomes are made from complexes of RNAs and proteins. Ribosomes are divided into two subunits, one larger than the other. The smaller subunit binds to the mRNA, while the larger subunit binds to the tRNA and the amino acids. When a ribosome finishes reading a mRNA, these two subunits split apart. Ribosomes have been classified as ribozymes, since the ribosomal RNA seems to be most important for the peptidyl transferase activity that links amino acids together.
Term
GTP
Definition
a purine nucleotide. It can act as a substrate for the synthesis of RNA during the transcription process. Its structure is similar to that of the guanine nucleobase, the only difference being that nucleotides like GTP have a ribose sugar and three phosphates, with the nucleobase attached to the 1' and the triphosphate moiety attached to the 5' carbons of the ribose
Term
Anticodon
Definition
a unit made up of three nucleotides that correspond to the three bases of the codon on the mRNA. Each tRNA contains a specific anticodon triplet sequence that can base-pair to one or more codons for an amino acid. For example, the codon for lysine is AAA; the anticodon of a lysine tRNA might be UUU.
Term
Amino acyl-tRNA synthetase
Definition
an enzyme that catalyzes the esterification of a specific amino acid or its precursor to one of all its compatible cognate tRNAs to form an aminoacyl-tRNA. This is sometimes called "charging" the tRNA with the amino acid. Once the tRNA is charged, a ribosome can transfer the amino acid from the tRNA onto a growing peptide, according to the genetic code.
Term
Activated amino acid
Definition
The product formed by the condensation of the acyl radical of an amino acid and adenosine 5'-monophosphate (originally in the form of adenosine 5'-triphosphate, with elimination of a pyrophosphoric group). Formed in the first step of protein biosynthesis.
Term
5' end of RNA
Definition
Term
3' end of RNA
Definition
Term
5' to 3' direction
Definition
Term
N-terminus of polypeptide
Definition
the start of a protein or polypeptide terminated by an amino acid with a free amine group (-NH2). The convention for writing peptide sequences is to put the N-terminus on the left and write the sequence from N- to C-terminus. When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus.
Term
C-terminus of polypeptide
Definition
the end of the amino acid chain terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus.
Term
Start codon
Definition
the point, sequence, at which a ribosome begins to translate a sequence of RNA into amino acids.
Term
Stop codon
Definition
nucleotide triplet within messenger RNA that signals a termination of translation
Term
Initiation-protein synthesis
Definition
two ribosomal subunits link onto the mRNA
Term
Elongation-protein synthesis
Definition
successive amino acids are added to the growing chain, brought in by transfer RNAs
Term
Termination-protein synthesis
Definition
end of a DNA sequence, beginning of RNA molecule
Term
Translation initiation complex
Definition
synthesis of a polypepitde using genetic info encoded in an mRNA molecule
Term
A site
Definition
ribosome binding site for tRNA,holds tRNA carrying amino acids to be added to polypeptide chain
Term
P site
Definition
ribosome binding site for tRNA, hold tRNA carrying growing polypeptide chain
Term
Release Factor
Definition
a protein that allows for the termination of translation by recognizing the termination codon or stop codon in a mRNA sequence.
Term
5' untranslated region (mRNA)
Definition
Term
3' untranslated region (mRNA)
Definition
Supporting users have an ad free experience!