Cell Cycle Control and Cancer

Monday January 28^th

What do you think would happen if a cell moved right into the Synthesis phase without making sure that G1 correctly occurred?

To answer this you needed to look and see what happens during the G1 phase.  During G1 the cell is growing and building more organelles.  If the cell just flew through to the S-phase there could be the chance that the cell had not grown large enough or built enough organelles to continue with the cell cycle.

What would happen if the cell did not properly go through the S phase and moved into G2 then mitosis?

For this questions we need to look at what is happening during the S phase.  During the S phase DNA is being replicated.  If the cell did not make sure that happened properly the cell may not have made a full copy of the DNA or the newly replicated DNA may be damaged and that will the be passed on to the daughter cell.

The Eukaryotic cell cycle takes MUCH longer than the prokaryotic cell cycle.  What are TWO reasons this may be?

Let's think about the differences between eukaryotic and prokaryotic cells.  The MAIN difference between eukaryotic and prokaryotic cells is the presence of a nucleus in eukaryotic cells.  Therefore, eukaryotic cells must perform mitosis and prokaryotic cells do not.  A second reason is that Eukaryotic cells have a LOT more DNA than prokaryotic cells and DNA replication would take much longer.

Tuesday January 29th we then got into notes about the cell cycle and how it was controlled.  below I have included some of the information we wrote down.

Thursday January 31^st

Cancer is defined the by Uncontrolled division of cells.

Ultimately what is the cause of cancer? (ALL cancer) Mutations in the DNA

Metaphase and Anaphase questions

Wednesday January 23rd

During Mitosis what do you think would be the result if Metaphase was skipped and the cell went straight into Anaphase? 

  The chromosomes would not separate equally and each of the resulting Nuclei would have different DNA.

I look under a microscope and notice a group of cells. Some cells have a nucleus that looks very “messy” with no defined structures.  There is one cell though that has very distinct structures forming within the nucleus.  What are these structures, what is so important about them being visible now, what stage of mitosis could we infer it is in?

 The Structures are Chromosomes, what is 

important about them being visible now is that 

they have condensed (this marks the beginning of

 mitosis) therefore this would be a cell in 

prophase

What about the “messy” cells – what stage of

 the cell cycle are they in?

 The other cells around would be in interphase. 

 At this time the DNA is uncoiled and looks just 

like a "blob".

Mitosis Notes

DNA Replication Notes

DNA Structure Notes

Daily Question Catch Up

Well, last week was a BLUR and I just realized I never added any of our daily questions or rundowns on here.  So here at least of the daily questions from last week and in another post I will place the note as well.  We are still in this land of Cell cycle, DNA, DNA Replication so there is a LOT of new information that seems very scattered but we are STARTING to put this all together!!  You guys are holding on strong - keep it up!

Monday January 14^th

Which Cell provides the most efficient surface-area to volume ratio and WHY?

 The smallest cell here would be the most efficient.  WHY??  Because of the three cells shown here it has the HIGHEST surface area to volume ratio.  Why is this important?  The more surface area there is, the faster a cell can obtain nutrients and release waste.  This is a KEY factor in cell size.  (And why cells cannot just grow infinitely large) 

Before a cell can divide what must the cell make a copy of?

ALL of the chromosomes (in human cells that would be 46 chromosomes)

Draw out what a duplicated chromosome would look like labeling the different parts.  Then describe how the two sides are related.

 The chromatids are EXACT copies of each other (same exact DNA on each side)

Tuesday January 15^th

DNA is made up of nucleotides.  What are the three parts that make up a nucleotide?

 

Of these, which two make up the backbone?  The Sugar (deoxyribose) and the phosphate group.

Which make up the “code” that writes our instructions?

 The nucleotide bases

There are 4 different “codes” in DNA, what are they and how do they pair up?

 Adenine, Guanine, Cytosine, Thymine

A pairs with T

C Pairs with G

(G Created All Things)

During the Cell cycle – when is this DNA replicated?

The S phase (Synthesis Phase)

Wednesday January 16^th

If given the following DNA Sequence, what would the complementary strand look like?

GCCTAAGCG

CGGATTCGC

In EACH one of our cells, how many of these nucleotides are there? (Recall from yesterday’s video) 6 BILLION

Thursday January 17^th

DNA replication is said to be semi-conservative.  Once DNA replication is completed how are the two resulting DNA molecules related to each other.

Each DNA molecule has one "original" or "Template" strand and one "new" Strand (See above how that works)

There are two “worker” molecules that perform DNA replication.  What are these two molecules and what type of organic molecule are they? DNA Helicase which "unzips" the DNA and DNA Polymerase which adds new nucleotides (again, reference the image above) These are Enzymes which are a type of Protein

Tuesday January 22^nd

In each of our cells, how many chromosomes are there? 46

These chromosomes are made up of both DNA AND Protein

Before a cell divides what MUST happen to the single chromosomes? It must replicate (to form sister chromatids) - see picture below

Then the cell goes through a process known as Mitosis which is the division of which part of the cell? The nucleus

Cell Reproduction and DNA - Back to the grindstone

On Monday i had you guys take some notes about the structure of DNA.  After your midterm you got some background information about cellular reproduction and today we started to merge the two together with the following daily questions.

Thursday January 10^th

About how many cells does your body make EVERY day?????? 2 Trillion

Where do these cells come from? Pre-existing Cells

What limits the size in which cells can get? The Surface Area to Volume Ratio and the DNA 

BEFORE a cell divides, what MUST happen first?? All the "equipment" a cell needs to function needs to copy (including the DNA)

What does DNA stand for? Deoxyribonucleic acid.

 

Of all the three parts of the nucleotides found in DNA, Which has 4 different options and ultimately writes the “code” for DNA - The nucleotide bases (adenine, guanine, cytosine, thymine)

After that we discussed the first couple pages of your reading guide using the online book.  Remember, you always have access to this from edline.  Here again is the info you need to access it. 

Use any of the following user names To access the online book go to http://my.hrw.com ALL passwords arebiology Usernames: bbiology20

cbiology19

dbiology1

ebiology8

fbiology7

gbiology9

hbiology28

ibiology3

jbiology7

kbiology3

lbiology6

mbiology16

nbiology3

obiology5

pbiology5

rbiology5

sbiology79

tbiology7

vbiology2

wbiology2

ybiology1

zbiology1