Chapter 7 Flashcards
Bacteria can transfer…
genetic information
What did Griffith determine?
that an unknown substance transmits as disease-causing trait between 2 types of bacteria
With the help of protein- and DNA-destroying enzymes, scientists subsequently showed…
that Griffith’s “transforming principle” was DNA
What did Hershey and Chase confirm?
the genetic role of DNA
By using viruses that infect bacteria (bacteriophages), Hershey and Chase confirmed that…
the genetic material is DNA and not protein
What is DNA’s shape and what does it contain?
double helix of nucleotides
What did Wilkins and Franklin provide
X-ray diffraction data
Watson and Crick combined these clues to…
propose the double helix of DNA
What did Chargaff discover?
that Adenine and Thymine, and Guanine and Cytosine occur equal in proportions in DNA
DNA is a ladder with what complementary bases?
Adenine with Thymine & Guanine and Cytosine
Amazing Timing & Good Cheese
What is crucial to a cell’s protein?
DNA
What are the two processes of protein synthesis?
Transcription & Translation
An organism’s genome includes what?
All of its genetic material
Most of the genome is divided among multiple chromosomes, which are…
discrete packages of DNA and associated proteins
What is a gene?
A stretch of DNA that is transcribed to RNA
What happens when a protein is produced?
a cell transcribes the gene’s information to mRNA which is translated into a sequence of amino acids
The two chains of DNA double helix are antiparallel with…
the end of one strand is 3’ and the end of the other is 5’
What does transcription use to create RNA?
DNA Template
Transcription uses what enzyme?
RNA polymerase enzyme
What does RNA polymerase enzyme bind to?
Promoter on DNA
What is the second step of transcription?
RNA polymerase builds on RNA molecule
How does Transcription end?
When RNA polymerase reaches a terminator sequence in DNA.
What happens after transcription?
The cells add a cap and poly A tail.
Introns are __ out of RNA.
cut
Exons are…
spliced together
What does translation require?
mRNA, tRNA, and ribosomes
What does mRNA carry?
a protein-encoding gene’s information
What does rRNA help with?
proteins to form ribosomes, WHICH SUPPORT AND HELP CATALYZE PROTEIN SYNTHESIS
What do cells regulate?
gene expression.
What are operons?
Groups of bacterial genes that share 1 promoter.
What does protein synthesis require?
A lot of energy input
Example of operon?
E. coli lac
What links mRNA to protein?
the genetic code
What is the correspondence between codons and amino acids?
the genetic code
What does mRNA join in the first step of translation?
a small ribosomal unit and a tRNA carrying an amino acid
When does a large ribosomal unit the join a smaller ribosomal unit?
Translation (after first step)
What happens during elogation?
Additional tRNA molecules carrying amino acids bring 2 subsequent mRNA.
What happens in termination?
the ribosome reaches a stop codon and is released, and the new polypeptide breaks free
What does a chaperone protein do?
help fold the polypeptide which may be shortened or combined with others to form the finished protein.
What has a codon sequence?
mRNA
What has an anticodon sequence?
tRNA
What occurs when the ribosome reaches a STOP codon?
Substitution, nonsense
When is the ribosome released?
Termination
A mutation that codes for a different amino acid is…
substitution, missense
A ___, mutation is an example of a ___ mutation.
substitution, point
A ___ mutation is an example of a frameshift mutation.
deletion
Germline mutations will harm an offspring. True or false?
True
Somatic mutations will harm an offspring. True or false?
False
A mutation that will code for the exact same amino acid is…
Silent
Who discovered bacteria could transfer genetic material?
Griffith
Who is the scientist who formulated the transformation principle in genetics?
GRIFFITH
What are Adenine and Guanine?
Purines
What are Thymine and Cytosine?
Pyrimidines
How many hydrogen bonds are between Adenine and Thymine?
2
How many hydrogen bonds are between Guanine and Cytosine?
3
What never change in DNA?
Phosphate group and deoxyribosugar
Multiple amino acids in a chain are called?
polypeptide chain
