Microbiology: The Genetics Of Microorganisms

Front 1

Who discovered the structure of DNA?

Back 1

James Watson and Frances Crick

Front 2

How long would the DNA molecule be in a bacterial chromosome measure if it were stretched out?

Back 2

1 mm (1000 time longer than the cell itself)

Front 3

The molecule is a string of______that are building blocks hooked together like a pearl necklace?

Back 3

deoxyribonucleotide (nucleotide for short)

Front 4

Each individual nucleotide consists of 3 smaller components. What are they?

Back 4

1. A molecule of deoxyribose
2. A molecule of phosphate
3. A Nucleoside base (base)

Front 5

List the 4 kinds of nucleoside bases.

Back 5

1. adenine (A)
2. guanine (G)
3. cytosine (C)
4. thymine (T)

Front 6

What is the term for the "linking together" of nucleotides?

Back 6

Polymerization

Front 7

What forms the long part of the DNA strand?

Back 7

deoxyribose and phosphate portions

Front 8

What forms the short part of the DNA strand?

Back 8

nucleoside bases
A,G,C,T

Front 9

Single strand of DNA

Back 9

ssDNA

Front 10

Where does a single strand of DNA occur?

Back 10

In some viruses

Front 11

double strand of DNA

Back 11

dsDNA

Front 12

What are the 2 strands in a dsDNA held together by?

Back 12

They are held together by hydrogen bonds that form between pairs of nucleoside bases.

Front 13

What shape is the dsDNA?

Back 13

A double helix

Front 14

Hydrogen bonds connect Adenine to...?

Back 14

Thymine

Front 15

Hydrogen bonds connect Guanine to...?

Back 15

Cytosine

Front 16

Hydrogen bonds connect Thymine to...?

Back 16

Adenine

Front 17

Hydrogen bonds connect Cytosine to...?

Back 17

Guanine

Front 18

The critically important feature of DNA structure is__________________________.

Back 18

The way the two strands are held together by hydrogen bonds between As and Ts and Gs and Cs

Front 19

What are the two kinds of reactions for DNA?

Back 19

Replication and Gene Expression

Front 20

Replication

Back 20

DNA molecule is precisely duplicated and accurate copies are passed on to progeny cells

Front 21

Gene Expression

Back 21

The process by which the information stored in DNA is used to tell the cell what to do.

Front 22

What two things are determined by gene expression?

Back 22

Which kinds of RNA and Protein molecules are made.

Front 23

The two steps of gene expression are called...

Back 23

Transcription and Translation

Front 24

The first stage of Replication is______

Back 24

Separating the double into two single strands.

Front 25

The lineup of free nucleotides is_______, to the lineup of bases in the DNA strand. ie. G-C, A-T

Back 25

Complementary

Front 26

Nucleotides that contain a single phosphate group.

Back 26

nucleoside monophosphates

Front 27

Free nucleotides contain 3 phosphate groups that are called______.

Back 27

nucleoside triphosphates.

Front 28

Whate are the activated forms of DNA building blocks?

Back 28

Nucleoside triphosphates

Front 29

What is a pyrophosphate?

Back 29

two phosphates joined together?

Front 30

How is a pyrophosphate formed?

Back 30

As nucleotied triphosphates are polymerized to make a new strand of DNA, a pyrophosphate is split off each one of them.

Front 31

The points of separation in the replication bubble are called_______?

Back 31

Replication Forks or replisomes.

Front 32

The old strands act as________ for forming the new strands

Back 32

Templates

Front 33

Because the new double helices are composed of one new and one old or conserved strand, the process is called__________.

Back 33

Semi-conservative replication

Front 34

The bubble that initiates replication of the circular bacterial chromosome forms at a genetically specified point on the chromosome called the_______.

Back 34

Origin

Front 35

The point where the 2 replication forks eventually meet.

Back 35

Terminus

Front 36

The enzymes in a replication fork form a loose complex called the________.

Back 36

Replication Apparatus

Front 37

What 3 functions does the replication apparatus perform?

Back 37

1. Separating the strands of the old dsDNA
2. Synthesizing two new single strands
3. Moving the replication fork

Front 38

What two functions does the DNA helicase enzyme perform during replication?

Back 38

1. Separating the stands of old double helix.
2. Moves the replication fork

Front 39

What keepsthe exposed single strands of DNA separate during replication?

Back 39

single-strand binding proteins (SSBP)

Front 40

What enzyme synthesizes the two new single strands by joining the nucleoside triphosphates paired with the exposed bases on the single strands?

Back 40

DNA polymerase III

Front 41

The two strands of DNA in a double helix run in opposite directions. So they are ___________.

Back 41

Antiparallel

Front 42

Any strand of DNA has direction called___________ because of the way its deoxyribose units are joined together.

Back 42

Polarity

Front 43

What does Antiparallel mean?

Back 43

It means that the two single strands in any double helix are aligned in opposite directions. The 3' end of one strand is next to the 5' end of the other.

Front 44

A strand of DNA that is being lengthened by Polymerase III is called a __________.

Back 44

Primer

Front 45

Can DNA polymerase III move in many directions?

Back 45

No it can only move in one direction.

Front 46

Because DNA strands are antiparallel and because DNA polymerase III can only move in one direction, only one of the two strands at the replication fork can be extended continuously in the same direction that the replication fork is moving. This strand is called the ___________.

Back 46

Leading strand

Front 47

The other strand that doesn't move with the polymerase III is called the ___________.

Back 47

Lagging strand

Front 48

What direction must the lagging strand be replicated?

Back 48

In the opposite direction to the forks movement.

Front 49

How is the lagging strand replicated?

Back 49

It's done by synthesizing short pieces of DNA as DNA polymerase III moves away from the fork.

Front 50

What three enzymes are needed to replicate the lagging strand?

Back 50

1. Primase
2. DNA plymerase I
3. DNA Ligase