Chapter 10 Flashcards
What must genetic material be capable of doing? (3)
- Replicating
- generating variation across generations
- storing and expressing info
Which 3 experiments (who did them) proved that DNA was genetic material?
- Griffiths
- Hershey & Chase
- Avery, McLeod, and McCarthy
What experiment helped prove this?
Exposing yeast to either 260 or 280nm UV light. 260 nm damaged DNA, whereas 280nm damages proteins. Cells exposed to 260nm light had more defects, showing that DNA must underlie inheritance
What is DNA made up of?
nucleotides
Adenine, guanine, cytosine, thymine
What are nucleotides made up of?
A phosphate group, sugar, and base
Define deoxyribose
Pentose sugar in DNA that is missing oxygen on the 2nd carbon.
Define ribose
Pentose sugar in RNA that has the hydroxyl group on the 2nd carbon
What does the 1’ Carbon do?
Connect to the base (A,T,G,C)
What does the 2’ Carbon do?
Contains/lacking the hydroxyl group - differentiates between deoxyribose and ribose sugar
What does the 3’ Carbon do?
Connects to the adjacent nucleotide - specifically to the phosphate of another group
What does the 5’ Carbon do?
Connects to the phosphate group
Define pyrimidine
One-ring bases
Cytosine, Thymine, and Uracil
Define purine
2-ring bases
Guanine and Adenine
Define phosphodiester bond
Bond attaching a phosphate group to the 5’C of one sugar and the 3’ hydroxyl group of a previous sugar.
(Phosphate-sugar bond)
Define nucleoside
NO phosphate group
Define nucleoside monophosphate
NMP. AKA nucleotide. Contains 1 phosphate group
Define nucleoside diphosphate
NDP. 2 phosphate groups
Define nucleoside triphosphate
NTP. 3 phosphate groups
What is a ribonucleoside?
ribose sugar with no phosphate group
What is the nomenclature for ribonucleosides of:
adenine
cytosine
guanine
uracil
Adenosine
Cytidine
Guanosine
Uridine
What is a ribonucleotide?
Ribose sugar with a phosphate group present
What is the nomenclature for ribonucleotides of:
adenine
cytosine
guanine
uracil
Adenylic acid
Cytidylic acid
Guanylic acid
Uridylic acid
What is a deoxyribonucleoside?
A deoxyribose sugar, no phosphate group
What is the nomenclature for deoxyribonucleosides of:
adenine
cytosine
guanine
uracil
Deoxyadenosine
Deoxycytidine
Deoxyguanosine
Deoxythymidine
What is a deoxyribonucleotide?
Deoxyribose sugar with a phosphate group present
What is the nomenclature for deoxyribonucleotide of:
adenine
cytosine
guanine
uracil
Deoxyadenylic acid
Deoxycytidylic acid
Deoxyguanylic acid
Deoxythymidylic acid
What do NTPs do?
Nucloside Triphosphates have several biological roles in the form of:
ATP
GTP
dNTPs
What is ATP?
Adenosine Triphosphate. Releases energy to power biological reactions
What is GTP?
Guanosine Triphosphate. Major signaling molecule in cells
What are dNTPs?
Deoxynucleoside triphosphates. Building blocks for DNA synthesis. Releases 2 phosphates to have enough energy to build DNA.
What is a sugar-phosphate backbone?
Sugar and phosphates on the outside of the helix, forcing the structural component of each strand.
Which way do the strands face in a helix?
Antiparallel to eachother.
5’C is the top for one strand, 3’C is the top for the other.
What are the complimentary base pairs? How many bonds do they have?
Adenine - Thymine | 2H bonds
Guanine - Cytosine | 3H Bonds
What happens if there are more G/C pairs in a region?
The DNA is more difficult to open.
What is the diameter of the double helix
~20 Angstroms
What is an angstrom?
Measurement of the width of 1 H atom.
How many base pairs per complete turn of the helix?
~10
Define major groove
Larger gap between 2 points on the DNA backbone
Define minor groove
Smaller gap between 2 points on the DNA backbone.
How do proteins interact with these grooves differently?
Certain proteins only interact with the major, and some only interact with the minor. This controls transcription, DNA repair, and more.
Altering DNA shape can do what?
Regulate DNA function since DNA & protein shape must be complimentary.
What are the main differences between DNA and RNA (3)?
RNA is:
single stranded
Has a ribose sugar instead of deoxyribose
Uses uracil instead of thymine
Define RNA-dependent RNA polymerase
Genes that help replicate viral RNA genome. Also replicates genes to build a new capsid/envelope and defense from the host.
Define proteases
Enzymes that destroy host proteins
Define envelope
Phospholipid coating that protects the virus and helps it enter the cell
Define capsid
Protein layer under the envelop that surrounds the genome and any protein/molecules necessary to start an infection
What is a secondary RNA structure?
3D arrangement of the RNA molecule based on complimentary base pairing with itself. Influences RNA function.
What is a hairpin structure?
Double stranded region that loops back on itself
What is a bulge structure?
Small absence of base pairing (a few nucleotides) that cause a bend in the structure
What is a junction?
Point where the base paired strands split into different directions.
What do these structures provide?
Binding sites for proteins
What is the purpose of an RNA viral genome?
RNA can be replicated quicker and blends in with RNA normally found in the cytosol.
Define retrovirus
A virus that integrates it’s genome into our genome.
What are the steps to integration of a retrovirus RNA? (6)
- Retrovirus releases RNA genome into host’s cytosol
- RNA is reverse transcribed and converted into DNA
- DNA is integrated into our genome
- Virus is inactive until stress occurs and it is reactivated
- Virus DNA gets transcribed and translated
- Virus reforms and exits the cell
Why does the virus remain inactive until stress occurs?
Virus thinks cell may die, so “jumps ship” to ensure that it survives.
