Chapter 7 Biology

Front 1

In 1928 Griffith discovered the concept of transformation-refers to the bacterial pickup of of external_____ from the environment.

Back 1

DNA

Front 2

R is for because it lacks a capsule? mouse injected with harmless R________.

Back 2

rough, lives

Front 3

S stands for smooth because it has capsule and causes what? mouse injected with pathogenic___ dies.

Back 3

infection, S

Front 4

Heat killed ___ inactivated the bacterial capsule, mouse injected with inactive___ lives.

Back 4

S

Front 5

Mixing R w/ heat killed____. Mouse injected with heat killed S and live R dies! A substance has found in S was transferred to R. R strain is transferred from harmless into______. It was DNA that transferred.

Back 5

S, Pathogenic

Front 6

From Griffith experiments Macleod and McCarthy, wanted to know what the transferring agents were. So, they used protease - protein killing proteins to kill all active proteins. The scientists concluded that______ was the transforming agent.

Back 6

DNA

Front 7

Alfred Hershey and Martha Case used a________(a virus that infects bacteria). This complex virus is composed of only proteins and______. The DNA is found inside a capspid which is made of protein. look up on you tube of Alfred Hershey Martha Case

Back 7

bacteriophage, DNA

Front 8

Watson, Crick, Wilkins, Franklin elucidated the DNA 's structure and were awarded the Nobel prize.______ a woman died before she could be presented it.

Back 8

Franklin

Front 9

DNA is a double helix made of two strands of______ which are: adenine, thymine, guanine, and, citosine. Each nucleotide is composed of a________ (5 carbon sugar, phosphate group and, nitrogenous base.

Back 9

nucleotides, deoxyribose

Front 10

The DNA structure shows the bases on the inside of the helix and -_____-____-groups on the outside. Both strands of DNA are complementary. This means that if there's an A on one strand there is a___ on the other strand and that if there's a G on one strand, there's a___ on the other strand. This finding was also confirmed by Erwin Chargaff.

Back 10

sugar phosphate, T, C

Front 11

Chargaff studied DNA samples from different organisms and found that in all of his samples the amount of A was always equal to the amount of T_________ and that the amount of C was always equal to the amount of G nucleotides. We call this now the ______-_______ rules: The base A hydrogen bonds with T and C hydrogen bonds with G.

Back 11

nucleotides, base pairing

Front 12

Both strands of DNA are _________. This means that the strands are oriented in__________directions based on the numbering of carbon atoms of the_______ (3' and 5'). One chain ends in 3' carbon, the other ends in 5' carbon. We can also say that one strand runs 5'-__' while the other one runs 3'-__'.

Back 12

antiparallel, opposite, sugar, 3, 5

Front 13

Radioactive sulfur was used to label the DNA of the bacteriophages.T/F

Back 13

False

Front 14

In __________, the cell copies the information on the DNA and makes a molecule of RNA(another type of_____ ___; this RNA will be called the messenger RNA or simply mRNA because it carries out the_______ from the DNA in order to build a protein). This process takes place in the_______ of an eukaryotic cell.

Back 14

transcription, nucleic acid, message,nucleus

Front 15

Cells build proteins based on the information present on the DNA in two major steps: _________ and_________.

Back 15

transcription, translation

Front 16

In _______, the information present on the mRNA is used to build a_______. Because proteins are built on ________ and ribosomes are found outside of the nucleus, we will say that translation takes place in the________of the cell.

Back 16

translation, protein, ribosomes, cytoplasm

Front 17

3 types of RNA: 1.______? (mRNA) is the one that carries the information or code from the DNA that is specific to build a protein. This is the type of RNA that is made during__________.

Back 17

messenger RNA, transcription

Front 18

3 types of RNA: 2.____? (rRNA) combines with proteins to form a _________, which are the cellular structures where protein synthesis takes place.

Back 18

ribosomal RNA, ribosome

Front 19

_______? (tRNA) carries amino acid to the ribosomes. Remember that proteins are polymers of amino acids so if the cell is going to build a protein, it will need the building blocks (i.e.________ _____) to do that.

Back 19

transport RNA, amino acids

Front 20

Stage 1 of transcription (initiation) : During initiation, the enzyme RNA polymerase binds to the ______ (a special region found at the beginning of a gene). Upon binding, RNA polymerase unwinds the DNA exposing the DNA_________strand.

Back 20

promoter, template

Front 21

2nd stage of transcription (elongation): During _______, RNA polymerase starts building the mRNA in the 5' to 3' direction. To do that, RNA polymerase scans the 3' – 5' strand of the DNA. The mRNA contains U (_____) instead of T (thymine). The resulting mRNA molecules runs in the 5'-3' direction.

Back 21

elongation, uracil

Front 22

third stage of transcription:(termination) During termination, RNA polymerase reaches the _______ sequence found at the end of the gene which signals the end of transcription . DNA reforms the double helix and________ is finished.

Back 22

terminator, transcription

Front 23

(note for transcription) Please note that while DNA replication takes place on the entire molecule of DNA, the process of_______ only takes place on the genes that need to be turned on for the synthesis of_______.

Back 23

transcription, proteins

Front 24

(1st modification to mRNA) The first modification is the addition of a "cap" to the 5' end of the mRNA. The "cap" is a modified__nucleotide. This helps the mRNA to exit the nucleus and direct it to the________.

Back 24

G, ribosome

Front 25

The second modification to the pre-mRNA is the addition of a poly__ tail to the 3' end. This process usually adds 100-200 A_________ and its function is to protect the mRNA from_________.

Back 25

A, nucleotides, degradation

Front 26

The third modification of the mRNA is the removal of the _____ (which are intervening non-coding sequences; exonsare the coding sequences). The process of removing the introns is called ________.

Back 26

introns, splicing

Front 27

After a mature mRNA has gone under all three stage and they are fully met it exits the nucleus and goes where?

Back 27

to the ribosomes.

Front 28

the 5 cap helps mRNA exit the nucleus. T/F

Back 28

t

Front 29

mRNA carries what

Back 29

the DNA information

Front 30

this is an important component to ribosomes

Back 30

rRNA

Front 31

carries amino acids to ribosomes

Back 31

tRNA

Front 32

This is the process by which cells build a protein (polymer of amino acids) from the information present on the mRNA produced during transcription?

Back 32

Translation

Front 33

This process takes place in the cytoplasm, specifically in theribosomes.

Back 33

translation

Front 34

The mRNA is read in sets of 3 letters (a_______) which could specify an amino acid. The genetic code lists the 64 codons that could be found on the________ strand. Only 61 specify for amino acids while 3 codons are designated_______ codons.

Back 34

codon, mRNA, STOP

Front 35

The codon AUG is the_____ codon and also specify for an amino acid (Met). Note that most amino acids are specified by one or more_______.

Back 35

start, codon

Front 36

The mRNA produced from transcription is read in sets of 3 letters in the 5'-3' direction. Every 3 letters of the mRNA represents a ______.

Back 36

codon.

Front 37

The tRNA brings the specific amino acid to the ribosome by pairing its _____--- (a set of 3 letters on the tRNA) to the mRNA codon. The amino acid is attached to the tRNA at the amino acid attachment site (a site opposite to the_________).

Back 37

anticodon- for both blanks

Front 38

Amino acids are built together to form a protein. A ____ bond holds two amino acids together.

Back 38

peptide

Front 39

a tRNA an anticodon loop at the top and, an acceptor stem where the what attaches?

Back 39

ribosomes

Front 40

ribosomes are composed of two subunits one small and one large. both are made of proteins and what else?

Back 40

tRNA.

Front 41

In _______, the mRNA start codon (AUG) binds to small ribosomal subunit and the first tRNA anticodon binds to the first______ codon. 1st step of translation.

Back 41

initiation, mRNA

Front 42

In_______, the large ribosomal subunit attaches to the complex so that translation can start. The tRNA corresponding to the second codon attaches to the ribosomes and a covalent (_______) bond forms between adjacent amino acids. The ribosome then releases the empty first tRNA that does not longer contains its amino acid attached to the_____. The ribosome shifts down one codon allowing the third tRNA to bind. This process continues in which the polypeptide or protein grows one______acid at a time 2nd step of translation.

Back 42

elongation, peptide, stem, amino

Front 43

In _______, a stop codon (one of three possible three stop codons) is reached. The new polypeptide or protein is released. The two ribosomal subunits disassemble. After translation, the polypeptide produced must fold into its preferred_________ ._________ that do not fold correctly can be the cause of certain diseases, such as Alzheimer's disease and mad cow disease. 3rd step of translation.

Back 43

termination, conformation, proteins

Front 44

UUU is the amino acid code for?

Back 44

phenylalanine

Front 45

the start codon is?

Back 45

AUG

Front 46

how many stop codons are there?

Back 46

3

Front 47

A _______ is a change in the cell's DNA sequence. It is caused by errors during DNA synthesis or by external______such as chemical, X ray, UV light, among others.

Back 47

mutation, mutagens

Front 48

A point mutation or____-pair substitution results when one letter on the DNA is substituted for another. Amino acids can change. (we call this a________

mutation and this may cause a disease or disorder such as the case of sickle cell anemia).

Back 48

base, missense

Front 49

Change on the DNA might not have an effect on the final amino acid_____ (due to the fact that many amino acids are coded by more than one codon). When this happens we call it a _______ mutation. When the mutation places a STOP codon, the protein is not fully made and is called a _______ mutation.

Back 49

output, silent, nonsense

Front 50

Chemicals that damage DNA are called?

Back 50

mutagens

Front 51

What is a mutation that can take place on the sperm or, egg and can be passed on to future generations?

Back 51

germline mutations

Front 52

These types of mutations don't take place on reproductive organs and, can't be passed on to future generations?

Back 52

somatic mutations

Front 53

what type of mutation can have the worst effect on cells?

Back 53

frameshift mutation

Front 54

An ______ is a cluster of related genes in addition to a promoter and an operator.

Back 54

operon

Front 55

If lactose is absent from e. coli a protein called_________, binds to the operator region of the lacoperon. When the repressor is bound to the operator, transcription of the three genes is_______ because RNA Polymerase cannot go past the promoter during transcription.

Back 55

repressor, blocked

Front 56

When lactose is______, it binds to the repressor. When lactose is bound to the repressor, the repressor cannot longer bind to the operator and RNA Polymerase can perform_________.

Back 56

present, transcription

Front 57

how many genes are in the lac operon

Back 57

3

Front 58

transcription factors are found in what kind of cells?

Back 58

eukaryotic

Front 59

Transcription factors bind to the promoter or to another region called an _______. Binding of transcription factors enable RNA Polymerase to perform_________.

Back 59

enhancer, transcription

Front 60

Cells build proteins based on the information present on the DNA in two major steps: _________ and_________.

Back 60

transcription, translation