bio unit 6

Question 1

codons

Question 2

monomer of DNA

Answer 2

nucleotide

Question 3

polymer of DNA

Answer 3

DNA double helix

Question 4

3 parts of nucleotide

Answer 4

deoxyribose sugar, phosphate group, nitrogenous base (adenine, thymine, cytosine, guanine)

Question 5

sugar phosphate backbone

Answer 5

made up of phosphate and deoxyribose sugars bonded together with covalent bonds, P bonds to 3’ carbon of preceding nucleotide

Question 6

dna replication

Answer 6

genetic information is copied, occurs before cell division, allows complete transfer of genome from 1 gene to the next

Question 7

dna rep is semiconservative

Answer 7

results in DNA molecule containing 1 original strand and 1 newly synthesized compliment

Question 8

5’ end

Answer 8

phosphate terminus

Question 9

3’ end

Answer 9

hydroxyl terminus

Question 10

antiparallel

Answer 10

the two strands in DNA run antiparallel to each other

Question 11

5’-3’ direction

Answer 11

nucleotides can only be added when a growing strand is in this direction

Question 12

leading strand

Answer 12

the strand that will be synthesized continuously

Question 13

lagging strand

Answer 13

the strand that will be synthesized discontinuously (in fragments)

Question 14

helicase

Answer 14

unwinds the DNA strand

Question 15

topoisomerase

Answer 15

relaxes the supercoil at the replication fork

Question 16

replication fork

Answer 16

the location where the 2 strands are separated

Question 17

DNA polymerase

Answer 17

synthesizes new strands, requires RNA primers to initiate synthesis, attaches to the 3’ end of the template strand, builds strands in a 5’-3’ direction

Question 18

ligase

Answer 18

joins DNA fragments on the lagging strand

Question 19

4 steps of transcription

Answer 19

1. initiation
2. elongation
3. termination
4. mRNA processing

Question 20

transcription

Answer 20

DNA-RNA

Question 21

initiation

Answer 21

RNA poly binds to the promoter sequence on the template strand

Question 22

promoter sequence

Answer 22

specific series of nucleotides that are upstream from a gene

Question 23

template strand

Answer 23

coding strand of DNA, aligned for growing mRNA from 3’ end

Question 24

elongation

Answer 24

RNA poly matches the complementary RNA nucleotides to each DNA nitrogenous base to create pre-mRNA

Question 25

termination

Answer 25

RNA poly reaches the termination sequence on the template strand. RNA poly releases pre-mRNA + the DNA

Question 26

mRNA processing

Answer 26

a spliceosome removes introns + splices together the exons. this mature mRNA has a 5' cap + a poly-A tail added for stability and processing

Question 27

introns

Answer 27

junk RNA, exists during RNA processing, not included in mature mRNA, DON'T code for amino acids

Question 28

pre-mRNA

Answer 28

rna with introns and extrons. junk RNA has not been removed

Question 29

mature mRNA

Answer 29

introns have been removed. extrons plus 5' cap and poly-A tail for stability

Question 30

steps of translation

Answer 30

1. initiation 2. elongation 3. termination

Question 31

initiation of translation

Answer 31

5' of mrna binds to the ribosome, this pairs tRNA to mRNA codons, starting with AUG

Question 32

start codon

Answer 32

AUG

Question 33

elongation of translation

Answer 33

tRNA continues to pair w/ mRNA codons, amino acid chain is transferred onto amino acid of each incoming tRNA

Question 34

termination of translation

Answer 34

ribosome reaches stop codon, this releases the amino acid chain and the mRNA.

Question 35

mRNA

Answer 35

carries genetic info from DNA to the ribosomes

Question 36

codon

Answer 36

3 based sequence found on mRNA

Question 37

tRNA

Answer 37

helps create specific polypeptide sequence on ribosomes

Question 38

anti-codon

Answer 38

3 based sequence on tRNA

Question 39

rRNA

Answer 39

functional units of ribosomes responsible for protein assembly

Question 40

extrons

Answer 40

dif. exons are connected in mature mRNA transcript

Question 41

alternative splicing

Answer 41

splicing introns + connects retained exons in a mature mRNA transcript

Question 42

primary transcript

Answer 42

many different exons

Question 43

gene expression

Answer 43

the process by which instruc

Question 44

regulatory sequences

Answer 44

stretches of DNA that interact w/ proteins, can be used to inhibit/promote protein synthesis (locks)

Question 45

regulatory proteins

Answer 45

assist w/ promoting/inhibiting protein synthesis (aka keys)

Question 46

epigenetic changes

Answer 46

can effect gene expression, involve reversible modifications of DNA/histones

Question 47

histones

Answer 47

proteins used to wrap DNA around

Question 48

tissues

Answer 48

groups of cells w/ the same function

Question 49

phenotype of a cell

Answer 49

determined by combo of genes that are expressed

Question 50

cell differentiation

Answer 50

cells w/in the same organism having dif. phenotypes

Question 51

transcription factors

Answer 51

proteins that promote/inhibit transcription of a gene

Question 52

operons

Answer 52

closely linked genes that produce a single mRNA molecule during transcription

Question 53

operator

Answer 53

sequence that either inhibits/promotes transcription by binding w/ regulatory proteins

Question 54

regulatory genes

Answer 54

can control the expression of all the genes at the same time

Question 55

lac operon

Answer 55

inducible system, usually turned off

Question 56

inducers

Answer 56

molecules that can bind to the reg. protein + cause it to change shape

Question 57

causes of mutations

Answer 57

radiation, random errors

Question 58

radiation

Answer 58

UV rays, X rays, chemicals

Question 59

gene/DNA mutations

Answer 59

substitution/point mutations, deletion, insertion, chromosome

Question 60

substitution/point mutations

Answer 60

swap 1 nucleotide is removal

Question 61

deletion

Answer 61

a nucleotide is removed

Question 62

insertion

Answer 62

a nucleotide is added

Question 63

chromosome

Answer 63

extra, missing, or translocated chromosome

Question 64

protein mutations

Answer 64

missense, nonsense, frame shift, silent mutation

Question 65

missense

Answer 65

a single A.A. changes

Question 66

nonsense

Answer 66

early stop codon, incomplete protein

Question 67

frame shift

Answer 67

change every AA after ins/del

Question 68

silent mutation

Answer 68

no change, in AA seq.

Question 69

promoters

Answer 69

DNA seq. upstream of the transcription start site