BIO DNA

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1. 
DNA and RNA Structure
 

DNA and RNA are nucleic acids.

They consist of chemical units called nucleotides.

The nucleotides are joined by a sugar-phosphate backbone
 
2. 
DNA Bases and Shape
 

Adenine (A) pairs with thymine (T)

Cytosine (C) pairs with guanine (G) Shape:double helix

 
3. 
RNA bases
 

Uracil (U)

Cytosine (C)

Adenine (A)

Guanine (G)

 
4. 
DNA Replication
 
DNA strands separate
Each strand becomes a template for the assembly of a complimentary strand from a ready supply of free nucleotides.
Nucleotides line up one at a time along the template strand – following the base pairing rules
Enzymes catalyze the entire process…
 
5. 

Origin of replication

 
  • Site of start point for replication
 
6. 

Bidirectional replication

 
  • Replication proceeds outward in opposite directions
 
7. 
Replication Bubble & Forks
 

Origin of replication provides an opening called a replication bubble that forms two replication forks

DNA replication occurs near the fork

 
8. 
Primer & Okazaki Fragments
 

Synthesis begins with a

primer

Lagging strand made as Okazaki fragments that have to be connected later

 
9. 
Direction of DNA rep
 

Proceeds 5’ to 3’ direction

 
10. 
DNA is...
 
very fast, accurate, proofread and repairs self during rep
 
11. 
DNA polymerases:
 

Are enzymes

Make the covalent bonds between the nucleotides of a new DNA strand

Are involved in repairing damaged DNA

 
12. 
Transcription VS Translation
 

Transcription, the transfer of genetic information from DNA into an RNA molecule (switch T to U)

Translation, the transfer of information from RNA into a protein (AA) - every 3 bases -> AA

 
13. 
possible 3 base sequences
 
64 =genetic code (different comb = AA)
 
14. 
codon
 
3 base triplet, start and stop codons tell enzymes where to begin/end synthesis
 
15. 

As it is made, a polypeptide:

 
Coils and folds
Assumes a three-dimensional shape, its tertiary structure
Several polypeptides may come together, forming a protein with quaternary structure
 
16. 
mutagens & mutation
 
Physical or chemical agents that cause mutationsA mutation is any change in the nucleotide sequence of DNA -

Although mutations are often harmful, they are the source of genetic diversity, which is necessary for evolution by natural selection.

 
17. 
Types of Mutations
 

Base substitution, the replacement of one base by another

Nucleotide deletion, the loss of a nucleotide

Nucleotide insertion, the addition of a nucleotide

 
18. 
virus
 

Possess genetic material in the form of nucleic acids

Are not cellular and cannot reproduce on their own.

 
19. 
Bacteriophages, or phages
 

viruses that attack bacteria.

 
20. 
plant virus
 

Viruses that infect plants can:

Stunt growth

Diminish plant yields

Spread throughout the entire plant

Viral plant diseases:

Have no cure

Are best prevented by producing plants that resist viral infection

 
21. 
Animal Viruses
 

Viruses that infect animals are:
Common causes of disease
May have RNA or DNA genomes
Some animal viruses steal a bit of host cell membrane as a protective envelope.
 
22. 
HIV
 

HIV is a retrovirus, an RNA virus that reproduces by means of a DNA molecule.

Retroviruses use the enzyme reverse transcriptase to synthesize DNA on an RNA template.

HIV steals a bit of host cell membrane as a protective envelope.

 
23. 
AIDS
 

AIDS (acquired immune deficiency syndrome) is:

Caused by HIV infection and

Treated with drugs that interfere with the reproduction of the virus

 
24. 
Viroids
 

Viroids are small circular RNA molecules that do not encode proteins

 
25. 
Prions
 

Prions are misfolded proteins that somehow convert normal proteins to the misfolded prion version

Prions are responsible for neurodegenerative diseases including:

Mad cow disease

Scrapie in sheep and goats

Chronic wasting disease in deer and elk

Creutzfeldt-Jakob disease in humans

 
26. 
DNA vs RNA
 
DNA: T, double stranded, deoxyribose sugar RNA: U, single stranded, ribose sugar