DNA replication and sequencing

Question 1

structure of genetic material

Answer 1

-DNA double helix
-chromosome/chromatin organisation
-3D organisation of chromatin in nucleus

Question 2

maintenance / copying of genetic material

Answer 2

-replication

Question 3

function (gene expression) of genetic material

Answer 3

-transcription
-RNA processing
-translation

Question 4

replication

Answer 4

-helicase
-replication fork
-template
-leading strand
-lagging strand
-direction of DNA synthesis

Question 5

helicase

Answer 5

an enzyme that uses energy from ATP hydrolysis to separate the strands in the DNA duplex

Question 6

replication fork

Answer 6

the point at which strands of the parental duplex DNA are separated so that replication can proceed
(a complex of proteins inc. DNA polymerase can be found here)

Question 7

template

Answer 7

both DNA strands of the DNA duplex are used as template, so BOTH are copied

Question 8

leading strand

Answer 8

-synthesised CONTINUOUSLY
-in DNA rep, strand that is made from the 5’ to 3’ direction by continuous polymerisation at the 3’ end
-synthesised in the same direction as the growing replication fork

Question 9

lagging strand

Answer 9

-strand of DNA that must also grow towards the replication fork
-it is synthesised in the 5’ to 3’ direction also
-synthesised DISCONTINUOUSLY in the form of short fragments (5’-3’) that are later connected covalently

Question 10

direction of DNA synthesis

Answer 10

DNA synthesis grows 5’ to 3’ direction

Question 11

characteristics of DNA replication

Answer 11

-semiconservative process
-initiation at specific origins
-replication fork movement usually bidirectional
-DNA strands always elongated 5’-3’
-replication is semi-discontinuous

Question 12

semiconservative process

Answer 12

-splitting of strands of the parental duplex produces templates for the synthesis of a new complementary DNA strand
-so the daughter strands are complementary to the original template
-the newly replicated strand is composed of:
=one parental (old template) strand
=one newly synthesised (complementary)
strand
-so synthesis is SEMICONSERVATIVE