Ioe Dna Replication And Gene Expression

Front 1

DNA REPLICATION IS

Back 1

DNA replication is the copying of one molecule of DNA to produce two identical molecules.

Front 2

DNA REPLICATION IS ESSENTIAL IN ORDER TO

Back 2

DNA replication is essential in order to allow cells to divide

Front 3

DNA replication requires

Back 3

A TEMPLATE AND A PRIMER

Front 4

THE BACKBONES OF DNA AND RNA ARE FORMED BY

Back 4

Backbones of DNA and RNA
These are formed by 3’ to 5’ phosphodiester linkages

Front 5

DRAW HOW A PHOSPHODIESTER BOND LINKAGE IS FORMED WITH THE BIPRODUCT

Back 5

Front 6

DRAW AN ALTERNATIVE REPLICATION OF THE SUGAR PHOSPHATE BACKBONE OF NUCLEIC ACIDS

Back 6

Front 7

SOME DNA MOLECULES ARE .... AND SOME ARE

Back 7

Some DNA molecules are Circular and Supercoiled

Front 8

WHICH BASES ARE DOUBLE RINGED

WHICH BASES ARE SINGLE RINGED

HOW MANY HYDROGEN BONDS BETWEEN G-C AND A-T

Back 8

Front 9

DNA REPLICATION PROCEEDS USING WHAT MECHANISM, AND DEFINE IT

Back 9

A SEMI CONSERVATIVE MECHANISM

The normal process of DNA synthesis, in which the two original strands of the molecule separate, and each acts as a template on which a new complementary strand is laid down.

Front 10

WHAT HAPPENS DURING EACH ROUND OF DNA REPLICATION

Back 10

During each round of DNA replication the original parent molecule is unwound to provide two, single-stranded molecules which act as templates for the synthesis of complementary strands

Front 11

Unwinding of DNA to allow replication requires ....

Back 11

specific DNA-binding proteins and enzymes (helicases) and also energy derived from the hydrolysis of ATP

Front 12

WHAT DOES THIS UNWINDING HAVE AN EFFECT ON

Back 12

This unwinding puts a strain on the molecule by causing the overwinding of nearby regions

Front 13

WHAT DO DNA POLYMERASES REQUIRE

Back 13

DNA polymerases require a template and a primer

Front 14

WHAT IS DNA REPLICATION PRIMED BY

WHAT HAPPENS TO IT AT A LATER STAGE OF REPLICATION

Back 14

DNA replication is primed by a short stretch of RNA that is synthesised by primase. The RNA primer is removed at a later stage of replication

Front 15

WHAT DO All DNA polymerases have structural features in common

Back 15

THEY HAVE A
THUMB
PALM
EXONUCLEASE
AND FINGERS

Front 16

on cursory examination both strands of a DNA template appear to.........

Back 16

replicate continuously and in the same direction

Front 17

The formation of a phosphodiester bridge is catalysed by

Back 17

The formation of a phosphodiester bridge is catalysed by DNA polymerases

Front 18

DRAW HOW The formation of a phosphodiester bridge is catalysed by DNA polymerases

Back 18

Front 19

DNA polymerases can only add new nucleotides to an

Back 19

DNA polymerases can only add new nucleotides to an existing 3’-hydroxyl group

Front 20

DNA can only be synthesised in one direction

Back 20

5’ to 3’.

Front 21

Both strands are synthesised in the 5’ to 3’ direction.

BUT WHAT DIFFERS BETWEEN EACH STRAND

Back 21

leading strand is synthesised continuously whereas the lagging strand is synthesised in short pieces termed Okazaki fragments

Front 22

DEFINE

TRANSCRIPTION

TRANSLATION

Back 22

Transcription – the synthesis of RNA from a DNA template
Translation – the synthesis of Proteins using RNA

Front 23

NAME TEH PERCENTAGE OF EACH TYPE OF RNA IN E.COLI

Back 23

Front 24

Transcription mechanism of the chain-elongation process catalysed bY

SHOW HOW THIS IS DONE

Back 24

Transcription mechanism of the chain-elongation process catalysed by RNA polymerase

Front 25

Transcription is Initiated at

Back 25

Transcription is Initiated at Promoter Sites on the DNA Template

Front 26

WHERE ARE PROMOTER SEQUENCES LOCATED

Back 26

Promoter sequences are located just upstream of the transcription start site

Front 27

RNA synthesis is carried out by


REQUIREMENTS

Back 27

RNA synthesis is carried out by RNA polymerases

RNA polymerases require a template but do NOT require a primer in order to initiate RNA synthesis

Front 28

RNA polymerase unwinds about

Back 28

RNA polymerase unwinds about 17 base pairs of template DNA

Front 29

NAME 4 FEATURES IN THE TRANSCRIPTION BUBBLE AND WHAT IT CONSISTS OF

Back 29

Front 30

DESCRIBE WHAT HAPPENS INSIDE IT

Back 30

Duplex DNA is unwound at the forward end of the RNA polymerase and rewound at its rear end. The RNA-DNA hybrid rotates during elongation

Front 31

Some genes terminate transcription via

Back 31

Some genes terminate transcription via stable stem-loop structures followed by a series of uracil (U) residues

Front 32

WHAT IS THE SECOND METHOD OF TRANSCRIPTION TERMINATION

WHAT IS IT

Back 32

rho DEPENDENT TERMINATION

The Rho protein is an ATP-dependant helicase that binds the nascent RNA chain and pulls it away from RNA polymerase and the DNA template

Front 33

WHY IS THE CODING STRAND CALLED WHAT IT IS

Back 33

The other strand of DNA (black) is called the coding strand as it contains the same sequence as the mRNA except for thymine (T) in place of uracil (U).

Front 34

WHAT HAPPENS FOLLOWING TRANSCRIPTION TO MRNA

Back 34

Following transcription the mRNA is used as a template for protein synthesis via translation.

Front 35

THE LAGGING STRAND IS SYNTHESISED IN

Back 35

The lagging strand is synthesised in discontinuous sections from RNA primers