Ch 14& 10 cell cycle

Question 1

RNA primase

Answer 1

enzyme that makes RNA primers

Question 2

DNA polymerase

Answer 2

enzyme that makes new DNA strand

Question 3

leading strand

Answer 3

new DNA strand, made in 1 piece

Question 4

lagging strand

Answer 4

new DNA strand made in fragments

Question 5

chromosome

Answer 5

entire double helix of dna

Question 6

chromatids

Answer 6

identical copies of the same chromosome

Question 7

monomers -> polymers

Answer 7

extending of a chain of nucleotides, put in energy and add to the 3’ end.

Question 8

explain the double helix

Answer 8

each strand is 2 nucleic acids held together by a hydrogen bond
-run antiparalell

Question 9

G1 phase (DNA packaging)

Answer 9

https: //www.youtube.com/v/9kQpYdCnU14
- heterochromatin- regions not being transcribed= easier to compact
- euchromatin- cant be packaged as tightly because the code is still needed
- Dna is packaged by being wrapped around histones

Question 10

when are chromosomes visible?

Answer 10

when they are about to divide

Question 11

S Phase

Answer 11

semi-conservative=1 original dna strand in each new chromosome

• Requires
  1. an original dna strand to copy
  2. monomers to make a copy
  3. dna polymerase to do the copying

Question 12

what are two problems with DNA Polymerase

Answer 12

cannot start a new chain of nucleotides-only extend existing chain
-can only extend towards 3’ end

Question 13

prokaryote replication

Answer 13

single circular chromosome
-begins at origin of replication
outside circle replicates at 5’->3’ and inner circle works 5->3 in opposite direction.

Question 14

how does Procaryote cell division work

Answer 14

divide by binary fission

-build new cell inside then create a wall in between (septum) and pinch off at the septum

Question 15

explain eukaryote chromosomes

Answer 15

chromosome number=karyotype
human karyotype= 46
23 pairs

Question 16

explain eukaryotic replication

Answer 16

two linear strands are pulled apart by helicase and proteins are attached that leave them separated. then dna polymerase binds a second strand from 5’->3’
https://www.youtube.com/watch?v=i2kEHnBOA-Q

Question 17

replisomes

Answer 17

enzymes envolved in DNA replication
helicase-pulls dna apart
topolsomerse- ensures dna doesnt get coiled
DNA Polymerase
RNA Primase

Question 18

eukaryote DNA Relication

Answer 18

http://www.youtube.com/v/-mtLXpgjHL0

Question 19

telomerase

Answer 19

http://www.youtube.com/v/AJNoTmWsE0s
since dna is unable to complete on the lagging stand, telomeres come in and input their own code to complete the last part of the lagging strand

Question 20

DNA Repair

Answer 20

error during s phase are possible. although dna polymerase has a proofreading ability it still makes mistakes
specific repair mechanisms- fix only certain damages
-nonspecific= repairs multiple kinds of mutations

Question 21

photorepair

Answer 21

damage by UV light
UV causes adjacent thyamines to detach from adenine and attach to each other instead
-enzyme called photolyase uses remaining light to fix the broken bonds

Question 22

excision repair

Answer 22

excise=take away
3 steps
1. recognize damage
2. remove damaged area
3. resynthesize using exposed template

Question 23

End of s Phase

Answer 23

karyotype is doubled
2 identical verions of the same chromosomes= chromatids
held together by proteins at the centromere
-attach to cytoskeleton at kinetochores

Question 24

how many dna strands are in a chromatid

Answer 24

2

Question 25

after s phase

Answer 25

cell enters g2 phase

• increased number of organelles
• replicate centrioles
• once chromosomes are visible you are in the m phase (mitosis)

Question 26

name the 5 stages of mitosis

Answer 26

1. prophase
2. prometaphase
3. metaphase
4. anaphase
5. telophase
   https: //www.youtube.com/v/cvlpmmvB_m4

Question 27

prophase (mitosis)

Answer 27

1. chromosome becomse slightly visible
2. nuclear membrane starts to break down
3. centrioles move to opposite poles

Question 28

prometaphase

Answer 28

centrioles attach to chromosomes

-chromosomes begin to move to center

Question 29

metaphase

Answer 29

chromosomes align along the center

Question 30

anaphase

Answer 30

chromosomes begin to be pulled apart from the center to opposite poles

Question 31

telophase

Answer 31

nuclear membrane reforms and chromosomes cluster towards opposite poles

Question 32

cytokinesis

Answer 32

cleavage of cell forms into equal halves

line in cell= cytokinesis

Question 33

1. G1/s checkpoint (3 Checkpoints)

Answer 33

the point where the cell decides to divide

-is there enough for 2 cells?

Question 34

2. g2/m checkpoint (3 Checkpoints)

Answer 34

checks to see if there are enough organelles made for replication

Question 35

3. late metaphase checkpoint (3 Checkpoints)

Answer 35

checks to see if all chromosomes are attached to the spindle

Question 36

growth factors

Answer 36

tells cell to increase number of organelles

-overrides checkpoints

Question 37

cancer

Answer 37

uncontrolled growth of cells\

-failure of cell cycle control

Question 38

proto-oncogenes (mutation of this gene causes cancer)

Answer 38

protein that allows regular cell division

-if this mutates the gene is stuck in the on position and continues to make cells

Question 39

tumor-supressor genes (mutation of this gene causes cancer)

Answer 39

these are proteins that inhibit cell division
they also correct mutations, without them tumors will continue to grow
https://www.youtube.com/watch?v=eoWRZbtqB_s

Question 40

cell death

Answer 40

apoptosis= controlled cell division
necrosis= accidental cell death