Unit 5b

Question 1

What are the parts of a nucleotide?

Answer 1

phosphate group

5 carbon sugar deoxyribose; pentose

nitrogenous base

Question 2

_________ hold together the nucleotide. But __________ hold the nitrogenous bases together.

Answer 2

covalent bonds, weak hydrogen bonds

Question 3

purines are __________ and are _______________.

pyrimidines are _________ and are __________.

Answer 3

adenine, guanine, structure has two rings

cytosine, thymine, single ring structure

Question 4

The ___________ of DNA is formed by sugar and phosphate groups of each nucleotide.

Answer 4

backbone, sugar phosphate backbone

Question 5

Chargaff’s rule: _____________

Answer 5

percentage of G=C and A=T

Question 6

__________ molecules contain coded information for making proteins. _________ is a long chain of nucleotides.

The three main differences of DNA vs. RNA:
1.
2.
3.

Answer 6

RNA, RNA,

Sugar in RNA is ribose
RNA is single stranded
RNA uses uracil instead of thymine

Question 7

What are the 3 main RNA?

Answer 7

messenger, ribosomal, transfer

Question 8

___________ consists of DNA that is tightly coiled around proteins called _________. The DNA and histone molecules form a beadlike structure called a _____________

Answer 8

chromatin, histones, nucleosome

Question 9

DNA is anti _______. The head of one strand of DNA is _______________. The tail of the other strand is ____________. The phosphate is ______ and the pentose is ____.

Answer 9

parallel, 5’, 3’, 5’, 3’

Question 10

free nucleotides can be added to _________ but NOT the _________. this is important for DNA replication.

Answer 10

3’, 5’

Question 11

DNA helicase _____________
DNA polymerase _____________-
Topoisomerase ____________
DNA primase ________________
DNA ligase _______________.

Answer 11

unravels DNA molecule

adds DNA molecules to the developing DNA strand

stabilizes/organizes the unraveled DNA molecule

adds RNA primer

stitches together Okazaki fragments

Question 12

All chromosomes have a base sequences called __________. DNA replicates in both directions forming ______________

Answer 12

origin of replication (ori), two replication forks

Question 13

______________ uses energy from ATP hydrolysis to unwind the DNA by _____________.

There will be _________ replication bubbles with 2 replication forks each formed during DNA synthesis

Answer 13

DNA helicase, breaking hydrogen bonds between base pairs, multiple

Question 14

DNA primase adds the ____________ that attracts _________. This is required to start DNA replication. This is a short strand of RNA. Then —— begins adding nucleotides to the _________ of the primer.

Answer 14

RNA primer, DNA polymerase, DNA polymerase, 3’

Question 15

DNA polymerase moves along the DNA strands in the ___________ direction but is making a DNA strand that is ____________.

The _______ is pointing in the correct direction for replication

The _______ is in the wrong direction which makes the DNA polymerase move back then go forward.

Synthesis of the —— occurs in small _________ stretches and results in ___________.

The lagging strand needs many _________.

Answer 15

3’ to 5’, 5’ to 3’ , leading, lagging, discontinuous, Okazaki fragments, RNA primers

Question 16

To prevent DNA from shrinking, cells have _________. _________ is active in cells that divide frequently, but inactive in most adult cells. This enzyme extends telomeres.

Answer 16

telomeres, telomerase

Question 17

DNA polymerase ___________ as it goes.

Answer 17

proofread.

Question 18

Two identical DNA molecules are formed each with an old strand and a new strand. This is called __________________.

Answer 18

semi-conservative replication

Question 19

The ________ strand is where a new _______ strand is formed.

Answer 19

template, complementary

Question 20

What does messenger, ribosomal, and transfer RNA do?

Answer 20

carries the instructions for making amino acids into proteins

part of the ribosome

transfers amino acids to the ribosome as it is specified in the messages in the mRNA

Question 21

protein synthesis takes place in two steps: ________________.

Answer 21

transcription, translation

Question 22

DNA cannot leave the nucleus so _________ takes place so that it can be transferred to the ribosome.

Answer 22

transcription

Question 23

what is a promoter?

Answer 23

a REGION of DNA where proteins bind to initiate transcription of that gene. usually before a gene

Question 24

______________ binds to the DNA promoter where transcription is to begin and then ____________ the gene that needs to be copied. Looks for the _______ as a signal. Only the _____________ is used.

Answer 24

RNA polymerase, unwinds, TATA box, template strand

Question 25

_______ is being added during transcription instead of thymine. RNA polymerase uses complementary base paring rules to match RNA nucleotides with the exposed DNA molecules.

Answer 25

uracil

Question 26

RNA is made in the _______ direction but the DNA template is read in the ___________ direction.

Answer 26

5' to 3', 3' to 5'

Question 27

In transcription during initiation - __________ elongation - ________ termination - ________________

Answer 27

DNA unwinds at initiation site RNA polymerase creates antiparallel transcript using RNA nucleotides (no proofreading) specified by a specific DNA base sequence; the DNA is zipped back up

Question 28

RNA polymerase knows when to start and stop because it will only go to __________________.

Answer 28

promoters

Question 29

After transcription __________ takes place. ________ are removed because they are not involved in coding for proteins. __________ are kept because they are involved in protein synthesis.

Answer 29

RNA editing, introns, exons

Question 30

During RNA editing a ________ is added and a _________.

Answer 30

5' cap, 3' tail

Question 31

A codon is _______________.

Answer 31

a three letter word in RNA. This specifies a specific amino acid to be added to the polypeptide

Question 32

AUG is a __________ for protein synthesis

Answer 32

start codon

Question 33

_____________ is the process to read and follow the instructions carried on the mRNA to make a polypeptide.

Answer 33

translation

Question 34

the ________ moves during translation not the mRNA strand. This reads the instructions and makes the polypeptide.

Answer 34

ribosome

Question 35

The mRNA attaches to the ____________. The RIBOSOME reads the mRNA codons in the _________ direction starting at AUG.

Answer 35

ribosome, 5'to3'

Question 36

The large subunit of the ribosome has three tRNA binding sites. ____________ _________ _______

Answer 36

A site - binds with the anticodon P site - where tRNA adds its amino acid to the growing chain E site - where tRNA sites before being released.

Question 37

read notes on translation and transcription

Answer 37

read

Question 38

the amino acid is attached on the _________ and it drops it off to match with each codon. When the stop codon is reached the ribosome releases the competed polypeptide chain.

Answer 38

tRNA

Question 39

Each tRNA also has three unpaired bases which are called ______________. these are complementary to the one mRNA codon

Answer 39

anticodons

Question 40

the polypeptide chain is connected through ____________.

Answer 40

peptide bonds

Question 41

mutations are __________. gene mutations are _____. chromosomal mutations are ________.

Answer 41

changes in the genetic material, changes in a single gene, changes in whole chromosomes

Question 42

________ changes in one or a few nucleotides. _______ are bases changed to another.

Answer 42

point mutations, substitution

Question 43

________ is a shift in the reading frame of the genetic message. _________ is where a base is inserted and a _______ is where a base is deleted.

Answer 43

frameshift, insertion, deletion

Question 44

4 types of chromosomal mutations 1. 2. 3. 4.

Answer 44

deletions duplication inversion translocation

Question 45

deletion is duplication is inversion translocation

Answer 45

loss of all or part of a chromosome produce extra copies of parts of a chromosome reverse the direction of parts of chromosomes part of one chromosome breaks off and attaches to another

Question 46

what is nonsense silent missense missense conservative missense non conservative

Answer 46

convert codon to a stop codon doesn't change the amino acid coded for by the codon change in the amino acid coded for by the codon amino acid is similar/does the same thing as the original amino acid amino acid is completely different

Question 47

_________ helps to limit the impact of mutations. It means information is expressed more than once.

Answer 47

codon redundancy

Question 48

What is the TATA box?

Answer 48

a non-coding DNA sequence; indicates the point at which a genetic sequence can be read and decoded.it is located in the promoter region