BIOC 1

Question 1

DNA polymerase

Answer 1

• single active site
• exploits geometry of a=t and c=g base pairs
• kinetic selectivity
• Distinguish between rNTPS and dNTPS

Question 2

proof reading nuclease

Answer 2

• DNA pol= quite accurate

- DNA replication = extremely accurate

Question 3

Eukaryotic DNA replication

Answer 3

a) eukaryotes uses several DNA polymerases
b) eukaryotes DNA is replicated from multiple origins
c) telomerase extends chromosome ends

Question 4

Sanger method- dideoxynucleotide chain termination

Answer 4

A,C,T,G- have different colours lighten for sequence.
smaller fragments comes the fastest
can read sequence based on size

Question 5

Limitation of Sanger method

Answer 5

• sequence determined approx. 400-800 base pairs - chunks known as reads
• due to biochemistry of DNA pol and the resolution of polyacrylamide gel electrophoresis.
• most genes contain thousands of bp
• modern sequencing projects - produce complete sequences of large genomic regions.

Question 6

New sequencing technology- 454 sequencing

Answer 6

process steps
1-DNA library preparation
2- DNA amplified on beads in micro actors
3-DNA sequenced from in each micro actor

Question 7

transcriptome

Answer 7

All RNA molecules transcribed in a particular cell/cell line/tissue at a certain developmental stage under certain conditions

Question 8

transcriptome is different depending on:

Answer 8

1- which cell/cell line/ tissue
2- developmental stage
3- condition/treatment

Question 9

key steps in PCR

Answer 9

step 1: isolate DNA
step 2: amplify fragment of interest
- denature step (heat 2 min at 95 degrees C)
-primer annealing step ( specific DNA primers binds to gene of interest at 60 degree C)
-synthesis step( taq polymerase done at 72 degrees C)
step 3: repeat step 2

Question 10

real time PCR

Answer 10

• detection of PCR product fluorescence at each cycle of PCR

- computer bases analysis of the cycle fluorescence time course

Question 11

searching sequence databases

Answer 11

to find gene in a particular species
annotate genes in your species of interest
find sequence variation in gene of interest

Question 12

blast programs

Answer 12

basic local alignment search tools

Question 13

how genome sequence information is used in research

Answer 13

• identify genes or cDNA - might function in a similar way
• identify genes and cDNA - same function in different species
• example demonstrated how DNA information can be used to make new discoveries- benefit human kind