Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
45 Cards in this Set
- Front
- Back
|
Genes must be able to
|
store information
be replicated undergo mutations |
|
|
nucleic acid
|
polymer of nucleotides
|
|
|
nucleotides
|
monomer of DNA and RNA consisting of a 5 carbon sugar, bonded to a nitrogenous base and a phosphate group
|
|
|
Purine
|
type of nitrogen-containing base that has a double ring structure
Adenine Guanine |
|
|
Adenine ( A )
|
purine that acts complementary to the pyrimidine nucleotide thymine ( T ) in DNA
|
|
|
Guanine ( G )
|
purine that acts complementary to the pyrimidine nucleotide cytosine ( C ) in DNA
|
|
|
Pyrimidine
|
type of nitrogen-containing base that has a single-ring structure
Thymine Cytosine |
|
|
Thymine ( T )
|
pyrimidine that acts complementary to the purine nucleotide adenine ( A ) in DNA
|
|
|
Cytosine ( C )
|
pyrimidine that acts complementary to the purine nucleotide guanine ( G ) in DNA
|
|
|
Chargaff's Rule
|
1. The amount of A,T,G,& C in DNA varies from species to species
2. In each species, complementary amounts are equal in quantity |
|
|
complementary base pairing
|
hydrogen bonding between complementary purines
- carried out by DNA polymerase |
|
|
template
|
parental strand of DNA that serves as a guide for the complementary daughter strand produced during DNA replication
|
|
|
semiconservative replication
|
duplication of DNA resulting in two double helix molecules, each having one parental and one new strand
|
|
|
3 Steps to DNA Replication
|
1. Unwinding
2. Complementary base pairing 3. Joining |
|
|
Unwinding
|
- parental DNA strands unwind and "unzip"
- enzyme helicase breaks hydrogen bonds |
|
|
Rejoining
|
- complementary nucleotides join to form new strands
- each daughter DNA molecule has one old strand and one new strand - carried out by DNA polymerase |
|
|
Rate of sequencing error during the base pairing phase of DNA replication
|
1 in 100,000
|
|
|
Proofreading
|
process used to check the accuracy of DNA replication as it occurs and to replace base with the correct one
- only misses 1 in 1,000,000 |
|
|
DNA repair enzymes
|
one of several enzymes that restore the original base sequence in an altered DNA strand
|
|
|
One Gene - One Polypeptide Hypothesis
|
the hypothesis that one gene codes for one specific polypeptide
|
|
|
Polypeptide
|
polymer of amino acids linked by peptide bonds
|
|
|
Gene
|
a segment of DNA that specifies the amino acid sequence of a protein
|
|
|
RNA nucleotides
|
Adenine
Cytosine Guanine Uracil |
|
|
Uracil
|
A single-ring pyrimidine that occurs in RNA instead of thymine
|
|
|
Types of RNA
|
mRNA - messenger RNA
tRNA - transfer RNA rRNA - ribosomal RNA |
|
|
messenger RNA - mRNA
|
type of RNA that carries a message from DNA in the nucleus to ribosomes in the cytoplasm about what amino acid sequence to produce
|
|
|
transfer RNA - tRNA
|
type of RNA that delivers amino acids to the ribosomes
|
|
|
Ribosomal RNA - rRNA
|
type of RNA that makes up polypeptides are synthesized
|
|
|
Two steps to gene expression
|
transcription
and translation |
|
|
Transcription
|
process whereby a DNA strand serves as a template for the formation of mRNA
|
|
|
Translation
|
process whereby ribosomes use the sequence of codons in mRNA to produce a polypeptide with a particular sequence of amino acids
|
|
|
Genetic Code
|
universal code in DNA that specifies protein synthesis in all living things
|
|
|
Codon
|
3- base sequence in mRNA that causes the insertion of particular amino acids into a protein
|
|
|
Triplet code
|
codon consisting of a sequence of 3 nucleotide bases that represents a particular amino acid
|
|
|
Properties of the Genetic Code
|
1. degenerate
2. unambiguous 3. stop and start signals |
|
|
Steps to sequencing a protein
|
1. transcription
2. translation |
|
|
RNA polymerase
|
an enzyme that joins RNA nucleotides that are complementary to the DNA template during transcription
|
|
|
mRNA transcript
|
an RNA molecule that is carrying a specific message to ribosomes outside the nucleus
|
|
|
Ribosome
|
the site of protein synthesis in the cytoplasm of a cell that is made up of two subunits of rRNA and protein
|
|
|
anticodon
|
3-base sequence in a tRNA molecule that pairs with a complementary codon in mRNA
|
|
|
Polyribosome
|
a string of several ribosomes translating the same mRNA strand at once
|
|
|
Three steps required for translation
|
1. initiation
2. elongation 3. termination |
|
|
Initiation
|
the first step of protein synthesis that brings all the translation components together
|
|
|
Elongation
|
the protein synthesis step in which a polypeptide increases in length one amino acid at a time
|
|
|
Termination
|
the final step in protein synthesis during which all the assembled components of protein synthesis are separated
|
