Discovery Of Dna, Structure, And Replication

Front 1

Chromosomes are made out of ___ and ____

Back 1

protein and nucleotides

Front 2

____ ____ took the first step to answering the question of protein or DNA as the genetic material

Back 2

Frederick Griffith

Front 3

Griffith worked with Streptococcus pneumoniae, a type of bacteria that causes ____ (filling of the lungs with fluid).

Back 3

pneumonia

Front 4

He set up four different experiments using different mice and different strains of the S. pneumoniae. He used an S strain that was virulent, which means it is harmful, and an R strain that did not cause any harm. The S (smooth) strain had ____ and the R (rough) strain does not.

Back 4

an outer coat that protected it from an organism's immune system

Front 5

In the first experiment, S bacteria was used, and the mouse was

Back 5

dead

Front 6

In the second experiment, R bacteria was used, so the mouse was

Back 6

alive

Front 7

In the third experiment, heat-killed S bacteria was used, so the mouse was

Back 7

alive

Front 8

In the fourth experiment, R bacteria + heat-killed S bacteria was used, so the mouse was:

Back 8

dead

Front 9

__________ is the process in which bacteria is changed from one form to another by taking in the genetic material from an outside source.

Back 9

transformation

Front 10

3 ways for bacteria to take in genetic material

Back 10

1. Transformation - uptake of DNA through the cell membrane of bacteria, 2. Transduction - using viral carriers, 3. Conjugation - a tunnel is formed between bacteria to transfer genetic material

Front 11

____, ____, and ____ purified chemicals from the heat-killed S bacteria and isolated the components (ie. protein, DNA, etc.)

Back 11

Avery, McCarty, and MacLeod

Front 12

They injected each of the components into a live _ bacteria to try and transform it into an S bacteria

Back 12

R

Front 13

In 1952, the question of DNA or protein was finally answered by ____ and _____

Back 13

Chase and Hershey

Front 14

They used a _____, a type of virus that only infects and kills bacteria cells. A bacteriophage is only made of DNA and protein.

Back 14

bacteriophage

Front 15

A bacteriophage injects its genetic materia; into a bacteria cell and takes the bacteria cell over. Hershey and Chase determined that if they could find out if the injected material was ___ or _____, they would have answered the question "What is the genetic material?"

Back 15

DNA or protein

Front 16

Hershey and Chase made the phage's protein coat radioactive with __ so they could track the protein throughout the experiment

Back 16

35S with 35 as a superscript

Front 17

Hershey and Chase mixed the bacteria and the ____ together and let the phages infect the bacteria

Back 17

bacteriophages

Front 18

The mixture was then put in a _____ to knock the phages off of the bacteria

Back 18

blender

Front 19

They then placed the mixture into a ____, which psins materials really fast and separates mixtures. The machine separated out the bacteria fro mthe liquid ti was in. If the _____ had the radioactivity, the protein was not the genetic material and if the _____ had the radioactivity, the protein was the genetic material.

Back 19

liquid, protein

Front 20

The ___ was not the genetic material but to make sure it was the DNA they repeated the experiment and made the DNA radioactive with ____

Back 20

protein, 32P with 32 as a superscript

Front 21

____ was the genetic material. Now that it was determined that DNA was the genetic material, the new question was - what did it look like?

Back 21

DNA

Front 22

_____ and ____ discovered the shape of the DNA molecule 0 without this knowledge, we would not have fields such as genetic engineering, gene splicing and other DNA related fields of medicine.

Back 22

Watson and Crick

Front 23

The shape of DNA is known as a ___ ___. It looks much like a twisted ladder. It contains two sides (double) that are twisted together (helix).

Back 23

double helix

Front 24

DNA is made of monomers (sub units) called _____

Back 24

nucleotides

Front 25

A nucleotide consists of 3 parts

Back 25

1. a phosphate, 2. a sugar molecule - deoxiribose, 3. a nitrogenous base (1 of 4 possibilities- A, T, C, or G)

Front 26

DNA stands for

Back 26

deoxiribonucleic acid - the deoxirobse refers to the sugar in the nucleotide.

Front 27

There are 4 different types of nucleotides because there are 4 different types of

Back 27

bases

Front 28

The bases are

Back 28

A (Adenine), G (Guanine), T (Thymine), and C (Cytosine).

Front 29

Adenine and Guanine are made of 2 carbon rings are known as ____

Back 29

purines

Front 30

Thymine and Cytosine are made of 1 carbon ring and are known as ______

Back 30

pyrimidines

Front 31

The bases bond with each other in the _______ _____ of the DNA and make up the "rungs" of the ladder

Back 31

hydrogen bonds

Front 32

A only bonds with

Back 32

T

Front 33

G only bonds with

Back 33

C

Front 34

The matching of the bases is called ____. One strand of the DNA "complements" or matches with the other side of the DNA strand. A complements T and C complements G

Back 34

complementation

Front 35

The phosphate of one nucleotide is bonded to the ____ of the other nucleotide below it. The bases are attached to the deoxyribose sugar

Back 35

sugar

Front 36

The bases of the two nucleotides are bonded together down the middle of the molecule by weak _____ bonds

Back 36

hydrogen

Front 37

Cytosine and Guanine are bonded by _ hydrogen bonds and thymine and adenine are bonded by _ hydrogen bonds

Back 37

3, 2

Front 38

The phosphates and sugars make up the ______ of the DNA ladder and the bases make up the ______ of the ladder

Back 38

backbone, rungs

Front 39

The DNA molecule is _____. This means that the sugar-phosphate backbones run in opposite directions. This is due to the chemical bonds and arrangement of the molecules

Back 39

antiparallel

Front 40

Due to this antiparallel structure, the DNA molecule has a 3' (three prime) and 5' (five prime) end. 3' and 5' refer to the carbon number on the _______.

Back 40

deoxiribose

Front 41

The 3' end is bonded to a _____ group (OH) and the 5' end is bonded to a phosphate.

Back 41

hydroxyl

Front 42

While ____ and ____ are accredited with the structure of DNA, they used many other scientist's research to do it

Back 42

Watson and Crick

Front 43

______ took pictures of DNA using a process known as _____ ___. The pictures helped Watson and Crick discover the double helical shape of DNA.

Back 43

Franklin, X-ray crystallography

Front 44

______, a British scientist, worked closely with Franklin in taking x-rays of DNA.

Back 44

Wilkins

Front 45

During the S phase of interphase, DNA undergoes _____, which means that is making a copy of itself

Back 45

replication

Front 46

The reason for replication is so that the resulting _____ cells will have the same amount and type of DNA. If cells do not have the correct amount or type of DNA, they will not function properly.

Back 46

daughter cells

Front 47

In DNA replication, the DNA strand _______ or separates and new strands of DNA are made. The type of replication is called ________ replication because half of the old strand is in each of the new strands of DNA.

Back 47

unzips, semi-conservative

Front 48

When DNA replication was being discovered, scientists were not sure if DNA replicated in a ____ model, _____ model, or a _____ model

Back 48

conservative, semi-conservative, or dispersive

Front 49

Conservative model

Back 49

the parental double helix remains intact and a second, all-new copy is made

Front 50

Semi-conservative model

Back 50

the two strands of the parental molecule separate, and each functions as a template for synthesis of a new complementary strand.

Front 51

Dispersive model

Back 51

each strand of both daughter molecules contains a mixture of old and newly synthesized parts

Front 52

Steps to DNA Replication are coming up

Back 52

there are three steps

Front 53

1. The enzyme ____ unwinds (unzips) the parent strand and the ____ bonds are broken. The unzipped DNA serves as a template or pattern to the new strand being formed. Without this template, the DNA would not be exactly the same

Back 53

helicase unzips yer GENES!!!!!

Front 54

2. The helicase recognizes where to start DNA replication on a DNA strand due to the ____ ___ ____ - a specific DNA sequence that helicase recognizes and attaches to the DNA at that point.

Back 54

origin of replication

Front 55

3. The enzyme ____ (DNA polymerase) attaches free floating nucleotides to the template to make the new strand of DNA. The DNA polymerase moves up the strand and makes the complementary strand

Back 55

polymerase

Front 56

4. The enzyme ____ ____ bonds with the ____ fragments together by filling in the phosphate-sugar backbone.

Back 56

DNA Ligase, Okazaki

Front 57

5. ____, such as ____, "proofread" the DNA to make sure there are no mismatching of bases or damaged DNA. If there is a problem, these enzymes will remedy the situation by cutting out the damaged DNA or matching up the correct base. Although these measures are in place, they do not always work and mutations may arise.

Back 57

enzymes, nuclease

Front 58

6. The end product is two _____ pieces of DNA that will each go into a daughter cell after cell division has completed.

Back 58

separate

Front 59

DNA polymerase can only add nucleotides to the __ end of a DNA molecule - never the 5' end, so a DNA only elongates from 5' to 3'.

Back 59

3'

Front 60

The strand of DNA that is made from the 5' to 3' is called the _____ strand. The leading strand is a continuous piece of DNA.

Back 60

leading

Front 61

The DNA strand made from the 3' to 5' is called the _____ strand. This strand is made of pieces of DNA called _____ ______. Those are pieces of DNA that are made from 5' to 3'.

Back 61

lagging, Okazaki fragments