Monday October 26th, 2009

reproduction

sexual vs asexual
good bad good bad
recombinatio slow no need 2 cells no variability
survival expensive quick no mutation
need 2 cells easy
rostore apolation

Sexual reproduction need haploid cells and a crossing over.
Crossing over is needed for variability of gens


We saw some videos were they explain the types of sexual and asexual reproduction

Types of sexual reprodduction
internal
external

Types of asexual reproduction
Binary fission
iw a division in two parts wich each have the potential to grow to the size of the original cell


Budding
the two resulting cells are not equal size


Fragmentation or Clonal Fragmentation
(reproduction or cloning) a organism is split into fragments. Each fragment develop into mature ,
fully grown individuals that are a clone of the original organism.
the mothers cells are very important in this reproduction.


Spores genesis
the type of reproduction that the fungi family use. Is by spores; the spores go out of the mashroom (in this case).
It can be male or female spores and mashrooms; and then this mashrooms trough female or male spores. This
female or male spores need the opposite spore to build a diploid mashroom.


Regeneration
is said to regenerate a lost or damaged part if the part regrows so the original function is restored.


Partenogenesis
this is ffound in female where growth and development of embryos occurs with out fertilization by a male.


Hermaphrodistism
is only in animals and plants; they have both male and female reproductive organs, only one works correctly.

Intersex
is only in humans; they have both male and female reproductive organs, only one works correctly.

Marla Lopez

Monday October 19th, 2009

So this Monday 19th of October =)... We keep watching a little of mitosis, but also we started with meiosis. so this is :

Here is a video of the 4 Steps of mitosis: http://www.youtube.com/watch?v=2WwIKdyBN_s

1. Prophase: the DNA condense to cromosomes
2. Metaphase: the Cromosomes get in the spindles
3. Anaphase: while the cromosomes are on the spindle... they separate to both poles
4. Telophase: the cell divides into 2

Here is other video in which there are many cells doing mitosis in real time =O: http://www.youtube.com/watch?v=m73i1Zk8EA0

So here are some specification about mitosis:

-It happens in EVERY cell EXCEPT on sperm and ovum/ova
-The mitosis happens for reproduction
-It happens all the time... but mostly at GROWTH


These are the similarities between the mitosis and meiosis:


MITOSIS V.S. MEIOSIS
- Division -Division
- mother/daughter - mother/daughter
-all cells except Sexual cells - ONLY sexual cells
- 2 daughters (46 cromosomes) - 4 daughters (23 cromosomes)
- Diploid (genetic info.) -Haploid (genetic info)

Heres a video

http://www.johnkyrk.com/meiosis.html

Juan Pablo Campos

(Liga del ultimo video enviada por Fernando Lopez)

Friday, october 16th, 2009

Monday October 5th, 2009

Today we talked about the functions of the ribosomes.
Ribosomes are organelles of the cell that are in charge of a process called Translation.


DNA|RNA
A |A
T |U
C |C
G |G

There is a process in which some enzymes make a copy of DNA but is called RNA.
As you can see in the table above, RNA does not have the letter T, so it is the only change that occurs (T becomes U).

In DNA the letters in one strand will always be connected to another certain letter on the other strand:

A will always be with T & C will always be with G.

Example of a possible DNA structure:
C----G
G----C
C----G
T----A
A----T
T----A
G----C
A----T
C----G
C----G
G----C
A----T

RNA is a copy of only 1 strand (and replacing all T's with U's). So the copy of the DNA example would be:
DNA| RNA
G | G
C | C
G | G
A | A
T | U
A | A
C | C
T | U
G | G
G | G
C | C
T | U

Now what a ribosome would do with this RNA is divide it into groups of 3 letters:
GCGAUACUGGCU=
GCG - AUA - CUG - GCU

Now each group of three letters is called a codon.
Each codon is an Aminoacid, and has a name (the name of each codon is not important for us to memorize, the teacher
will give us a table with the names).
The names of the codons from the example would be:
GCG: alanina
AUA: soleucina
CUG: leucina
GCU: alanina

Now that each part of the RNA is a codon (group of aminoacids) it is a protein that can be used.

BRIEFLY:
RNA: copy of ONE strand of the DNA, but instead of T's has U's.
Ribosomes: converts the RNA into aminoacid chains that conform a protein (Translation).
DNA: has two strands (chains of letters), but only one will be used for the RNA copy.
Proteins: chains of aminoacids
A is to T as G is to C

Luz Garduño

last class we saw how RNA is transform into proteins so basically is a very simple process basically i tell these example and told it to martha and she understand:

imagine that you are in a candy shop and the RNA is the code for example PTP is a pulparindo TTU is a tootsie and BGB is a bubblegum so the RNA is kind of a list with the codes and you are the ribosome's for example in the list you have PTPBGBTTUTTUPTPBGBBGB so what you make is separate the initials in three and get the candies so you got basically a nice basket with a pulpariando then a bubblegum, tootsie,pulparindo,bubblegum,bubblegum, and that kind of linear basket is the protein.

AMINOACID:what makes up a three letter codons

CODON: a 3 letter group like a worg PTP

PROTEIN:a chain of codons

but so these posible can be possible you need kind of to"codify" those messages by finding theryre complementary letter here are the complementary letters for ATCG

A=T

T=A

C=G

G=C

But cause DNA does not has T its change into a U

Naneth Lopez Argil

The RNA copies the DNA Information. It gets to the Rough. E.R. (where the Ribosomes are) and the ribosomes, by the Translation Method, Translate the RNA and make it a Protein. Here is a more detail explanation http://nobelprize.org/educational_games/medicine/dna/index.html

A segment of RNA its at least one protein... those big chains of DNA that RNA copies... it know where to stop copying because of the Determination codes... are to determine where a chain ends. =)

http://nobelprize.org/educational_games/medicine/dna/b/replication/index.html
http://nobelprize.org/educational_games/medicine/dna/b/replication/replication.html
these are more info. of the Replicacion of DNA

And here is info of the genetic codes
http://nobelprize.org/educational_games/medicine/gene-code/about.html


Here is a video of RNA... its cool =) and understandable
http://www.youtube.com/watch?v=Ml0OqAUzEXU

Juan Pablo Campos

Friday, october 2nd, 2009

last Friday we talked about:
♣ the cell membrane: is the part of the cell that separates the cell of the outside, it controls the movement of the material that goes in or goes out. the cell membrane is a two-layered structure made up by lipids, proteins and carbohydrates. extra: also have the quality to be "selectively permeable", this means that it select what passes through it freely or just a slight or nothing at all.

♠the structure and functions of the organelles of the cell and how they work together, this is called the endoplasmatic system, the endomembrane system has a chemical structure (made up of phospholipids) different to the mitochondria. the main labor in here is to produce proteins.

organelles
the nucleus is the organelle that store inside of it the DNA.the DNA is like the blueprints of the cell, it tells to the cell what things it need to have, produce and all the information that it need to function. DNA can´t get out of the nucleus, so a copy of it, called RNA, is made. the RNA goes to the "rough endoplasmatic reticulum"
nucleus
in this picture it can be see a double membrane nuclear envelope (we didn´t saw it in class, i don´t thing it is important)

the endoplasmatic reticulum is together with the nucleus, this organelle is divided into two, the rough endoplasmatic reticulum (R.E.R) and the smooth endoplasmatic reticulum (S.E.R). in the R.E.R are located the ribosomes that translate the RNA that lays in there.
endoplasmatic reticulum
in this picture you can saw how close it is to the nucleus, also the R.E.R and the S.E.R, the little dots in the R.E.R are called ribosomes, the ribosomes are sites of protein synthesis in the cell. then it passes through S.E.R to get details and glucose.

the Golgi apparatus storage and packs the proteins together so they can be send to the part of the cell that requires them and in different amounts.
Golgi apparatus

the cilia and the flagella are made up of proteins their function is the cell´s movement, they usually are a few flagella on a cell but they are a lot of cilia that work in group opposite to flagella.
cilia and flagella structure
if you cut a cilia or a flagella, you can observe that their structure have 9 pairs of tubs, each tube push the next to him, with this movements between them, is the way the cell moves around, also they have to simple tubs in the center. this microtubules are composed of a protein named tubulin.








a question to ponder (reflexionar):

"why do have to eat proteins if we are capable to produce them?"
because we can produce some amino acids but not all of them
in total there are 20 aminoacids; in them are 8 aminoacids called "essential aminoacids", this ones we can´t produce them,
a way to get them easily is eating egg, because the yolk contains the 20 aminoacids


"the fabric analogy":

if you didn´t understand you can consider this analogy:

first, imagine a fabric from the outside, the only thing you can see is the wall, this wall is the cell membrane in our analogy, this fabric is divided in departments, every different department have a mission to accomplish, each department is an organelle, the director of the fabric, who directs everything from his office is the nucleus, this president of our fabric know everything, of course is his fabric, have all the ideas, the budged, the blueprints in his laptop (all the information: DNA) so, to let know his employees what they need to do, he send some memos(RNA) from his office, this is how every organelle knows what to do. in the production room (R.E.R) made ribosomes as the memo said, from here the ribosomes are send to put some details (S.E.R) later all that was produced pass to the quality inspection(Golgi apparatus), the boss whats to know if everything have a high quality standard. so in the Golgi apparatus the deficient product (lysosomes) can be sent back to the S.E.R or R.E.R even to the nucleus, because is a cycle system, the good product is packed and storage and when it is needed go out of fabric vesicles.

important concepts:
>cell: The basic structural and functional unit in people and all living things.
http://www.medterms.com/script/main/art.asp?articlekey=2661

>tissue:part of an organism consisting of an aggregate of cells having a similar structure and function
wordnetweb.princeton.edu/perl/webwn

>system: a group of organs that work together to perform a specific function. Biology The study of life Prentice Hall Schraer and Stoltze Page. 101

>chemical structure: A chemical structure includes molecular geometry, electronic structure, and crystal structure of a chemical compound
http://en.wikipedia.org/wiki/Chemical_structure

>organelles:is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid membrane.
en.wikipedia.org/wiki/Organelle

• nucleus: a part of the cell containing DNA and RNA and responsible for growth and reproductionwordnetweb.princeton.edu/perl/webwn
• RER: The "rough" appearance of the rough endoplasmic reticulum (RER) results from the presence of ribosomes that are bound to the cytosolic side of the endoplasmic reticulum membrane. The presence of ribosomes on the RER indicates that it is involved in protein synthesis.http://academic.brooklyn.cuny.edu/biology/bio4fv/page/rougher.htm
• SER: The smooth endoplasmic reticulum (SER) has no such bound ribosomes and is not involved in protein synthesis. However, the SER is involved in cholesterol metabolism, membrane synthesis, detoxification, Ca++ storage along with other cellular processes.http://academic.brooklyn.cuny.edu/biology/bio4fv/page/rougher.htm
• vesicle: Small membrane-bound spaces in most plant and animal cells that transport macromolecules into and out of the cell and carry materials between organelles in the cell. www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookglossV.html
  
• golgi bodies: serve as processing, packing and storage center for the products released form the cell. Biology The study of life Prentice Hall Schraer and Stoltze Page. 86
• mitochondria: round or slipper-shaped organelles that release the energy in food molecules for us by the cell. it is surronded by a double membrane. Biology The study of life Prentice Hall Schraer and Stoltze Page. 86
  

>endoplasmatic system: Membrane system within the cytoplasm of a eukaryotic cell, important in the synthesis of proteins and lipids. The ER usually makes up more than half the membrane of the cell and is continuous with the outer membrane of the nuclear envelope. There are two distinct regions of ER: the rough ER, or RER (so called because of the protein-synthesizing ribosomes attached to it), and the smooth ER (SER), which is not associated with ribosomes and is involved in the synthesis of lipids and the detoxification of some toxic chemicals.
http://encyclopedia2.thefreedictionary.com/Endoplasmatic+reticulum

>cilia: which is a hair-like structure that moves in a waving motion. Cilia are used for motility in some one-celled organisms and for moving particles or fluids in certain cells of more advanced organisms.http://score.dnr.sc.gov/deep.php?subject=10
>flagella: long whip-like tail protruding from the surface of a cell that propels the cell, acting as a locomotive device.www.dnr.state.md.us/Bay/cblife/glossary.html
>lysosome: An organelle found in all types of animal cells which contains a large range of digestive enzymes capable of splitting most biological macromolecules en.wiktionary.org/wiki/lysosome
>protein: A molecule composed of amino acids linked together in a particular order specified by a gene's DNA sequence. Proteins perform a wide variety of functions in the cell; these include serving as enzymes, structural components, or signaling molecules.
www.hhmi.org/genetictrail/glossary.html

Juana Montoya