chp 12

Question 1

griffith

Answer 1

• mice experiment

- concluded that dna can transfer from dead to alive things

Question 2

avery

Answer 2

• identified what transformed the dna

- confirmed that when s strain died dna was released

Question 3

hershey & chase

Answer 3

• used radioactive labeling to trace the dna and protein

- concluded that viral dna was injected into the cell

Question 4

chargaff

Answer 4

said guanine goes with cytosine and adenine goes with thymine

Question 5

nucleotide

Answer 5

• adenine
• guanine
• cytosine
• thymine

Question 6

purines

Answer 6

adenine and guanine

Question 7

pyrimidines

Answer 7

cytosine and thymine

Question 8

watson & crick

Answer 8

• made double helix model
  1. two outside strands of deoxyribose and phosphate
  2. thymine and adenine and cytosine and guanine pair together

Question 9

x-ray diffraction

Answer 9

helped discover that dna was actually double helix

Question 10

dna orientation

Answer 10

top strand is 5’ to 3’, bottom strand is opposite direction so 3’ to 5’

Question 11

chromosome structure

Answer 11

dna coils around histones to make chromatin

Question 12

dna replication

Answer 12

• occurs in eukaryotic nucleus

- happens before mitosis/myosis

Question 13

key enzymes in replication

Answer 13

• helicase “unzipper”
• primase “initializer”
• dna polymerase “builder”
• ligase “gluer”

Question 14

helicase

Answer 14

unzips the double helix structure

Question 15

primase

Answer 15

makes RNA primer for dna polymerase

Question 16

dna polymerase

Answer 16

builds new strand in 5’ to 3’

Question 17

ligase

Answer 17

glues everything together at the end of replication

Question 18

semiconservative replication

Answer 18

one strand of parental dna serves as a template and one strand of new dna so that the cell can still function

Question 19

unwinding

Answer 19

helicase is responsible for unwinding the double helix

- primase adds a short segment of RNA primer on each dna strand

Question 20

base pairing

Answer 20

dna polymerase adds appropriate nucleotides by adding to the 3’ end of the new dna strand

Question 21

leading strand

Answer 21

first strand that is stretched as the dna unwinds, other strand is lagging

Question 22

lagging strand

Answer 22

elongates away from the replication fork and is synthesized into small fragments called okazaki fragments

Question 23

joining

Answer 23

da polymerase removes the rna primer and fills in the place with dna nucleotides
- ligase links 2 sections

Question 24

eukaryotic replication vs prokaryotic replication

Answer 24

e: dna unwinds as dna is replicated
p: circular dna strand is opened at one origin of replication

Question 25

rna

Answer 25

single stranded

-contains sugar ribose and the base uracil instead of thymine

Question 26

messenger rna (mRNA)

Answer 26

-long strands of rna nucloetides that are formed complementary to the strand DNA

Question 27

ribosomal rna (rRNA)

Answer 27

-associates with proteins to form ribosomes in the cytoplasm

Question 28

transfer rna (tRNA)

Answer 28

• smaller segments of rna nucleotides that transport amino acids to the ribosomes

Question 29

transcription

Answer 29

dna code is transferred to rna in the nucleus

Question 30

introns

Answer 30

intervening sequences in rna processing

Question 31

exons

Answer 31

remaining pieces of dna that serve as the coding sequences

Question 32

codon

Answer 32

3 base code in dna/rna

Question 33

translation

Answer 33

tRNA molecules act as interpreters of the mRNA codon sequence

Question 34

anticodon

Answer 34

3 base coding sequence in the middle of th folded strand

Question 35

one gene one enzyme

Answer 35

one gene codes for one peptide

- genes are chemicals

Question 36

prokaryote gene regulation

Answer 36

-ability of an organism to control which genes are transcribed in response to the environment

Question 37

operon

Answer 37

a section of dna that contains the genes for the proteins needed for a specific metabolic pathway

Question 38

4 things needed for prokaryotic gene regulation

Answer 38

1. operator
2. promoter
3. regulatory gene
4. genes coding for proteins

Question 39

eukaryotic gene regulation

Answer 39

regulates transcription

Question 40

gene mutation

Answer 40

-permanent change that occurs in a cells dna

Question 41

types of mutation

Answer 41

• point mutation
• insertion
• deletion

Question 42

causes of mutations

Answer 42

• spontaneous
• chemicals and radiation can damage dna
• high-energy forms of radiation (x-rays, gamma rays) are higly mutagenic