Chapter 11 - DNA Flashcards
11.1
Virus?
a package of nucleic acid wrapped in a protein coat
can reproduce by inserting genetic info into living cell
11.1 explain what scientists conducted to determine that DNA carries genetic info? Griffith? Avery? Hershey and Chase?
Griffith - injected mice with harmless or harmful bacteria
Avery - concluded DNA was the transforming factor
Hershey and Chase - used viruses to confirm Avery’s conclusion with radioactivity
11.1
Bacteriophage?
A virus that infects bacteria
11.2
What is DNA?
Deoxyribonucleic Acid -
a molecule that stores genetic information.
11.2
What is DNA made up of? What are it’s 3 parts?
DNA is made up of NUCLEOTIDES.
3 parts -
- A sugar (deoxyribose)
- A phosphate group
- A nitrogenous base
11.2
Nitrogenous Base?
a single or double ring of carbon and nitrogen atoms with functional groups.
Single Ring - pyrimidines
Double Ring - purines
11.2
What is the shape structure of DNA?
a twisting shape, called a double helix.
two strands of DNA twist together with sugar phosphate backbone on the outside and nitrogenous base on inside
11.2
Nitrogenous Base Pairs?
Pyrimidines Purines
Thymine ———–> Adenine
Cytosine ————> Guanine
Uracil —————> Adenine
11.3
When is DNA copied? What is the process of copying the DNA molecule called?
DNA is copied before a cell divides.
DNA replication.
11.3
What forms the bonds between the nucleotides of the new DNA strand?
DNA polymerases
11.3
Steps of DNA replication?
- Two strands of double helix separate
- Uses each strand as pattern for making a complimentary strand.
- Nucleotides line up
- Enzymes link nucleotides together to form 2 new DNA strands called daughter cells.
11.4
How did Beadle and Tatum study the relationship between genes and proteins?
“One Gene - One Enzyme” hypothesis, states each gene controls the production of specific enzyme.
(used bread mold)
11.4
Transcription vs Translation?
Transcription : the DNA sequence is converted to a single stranded RNA molecule
(location : nucleus)
Translation : converts the nucleic acid sequence to an amino acid sequence
(location : cytoplasm)
11.4
Codon?
a three base sequence that codes for one amino acid
(start codon and stop codon)
(words are to sentences as proteins are to amino acids)
11.5
How many kinds of RNA are involved in making proteins?
Three (3)
11.5
Messenger RNA
(mRNA)
RNA molecule that is transcribed from the DNA
DNA strand ex : TAGCAAGCCT
I
RNA transcript
I
mRNA strand ex : AUCGUUCGGA
11.5
RNA polymerase?
joins the RNA nucleotides together during transcription
11.5
Introns vs Exons?
Introns - part of RNA that does not code for amino acids
Exons - coding regions of RNA
11.5
What happens to the RNA transcript before it is able to leave the nucleus?
What is this process called?
It is edited :
Introns are removed
Exons are put together
RNA SPLICING
11.5
Transfer RNA
(tRNA)
a type of RNA that translates the codons of mRNA to the amino acids
(a molecule with an amino acid binding site at one end and a three base anticodon at the other end.)
11.5
Ribosomal RNA
(rRNA)
type of RNA found in a ribosome
the tRNA anticodon binds to the mRNA codon to add the amino acid to the polypeptide
11.6
what is a mutation? two types of mutations?
a change in the nucleotide sequence of DNA
includes..
substitutions - one nucleotide is replaced (small effect = one word changed in sentence)
insertions or deletions - one or more nucleotides are added to or removed from a gene (serious effects = change of whole sentence)
11.6
What is a mutagen?
a physical or chemical agent that causes a mutation
11.1
What carries out genetic information and is responsible for producing genetic info?
DNA
this was determined in the experiment of Chase and Hershey
11.2
How are nucleotides joined to one another?
sugar - phosphate backbone
nitrogenous bases are attached to this backbone
