Check out how far this Leatherback Sea Turtle has traveled!

TOPP or Tagging of Pacific Predators tags various animals within the Pacific Ocean with satellite tags, some of whom are critically endangered, to study different characteristics of their lifestyle like their migratory patterns, what habitats they use, or for sea turtles, nesting sites.  This turtle here is a Leatherback, the world's most endangered sea turtle, who was tagged by TOPP researchers and followed. Check out the other animals TOPP tags and follows at: http://www.topp.org/

Get This Widget!TOPP.org

Darwin's Theory of Evolution - Simplified

When it comes to learning about evolution in class, your teacher may tell you A LOT about Charles Darwin, maybe even a little too much...

Although your teacher may quiz you on some random facts about Darwin's life, for instance what was the name of the ship he sailed on (FYI she was called the Beagle), here are the fundamental principles of Darwin's Theory of Evolution you should know:

~ All life is related and we all descended from one common ancestor. 

~ Organisms have evolved from this ancestor through a process called Natural Selection. 

~ Natural Selection refers to the ability of some organisms to outcompete others within a specific environment due to their "possession" of a particular trait. 

~ Because the organisms with a particular trait survived, they produce more offspring than those without. The organisms that survived and reproduced are said to have adapted to the environment their living in. 

Natural Selection leads to adaptation to a specific environment by "selecting" organisms with specific traits suitable for a particular environment 

~ In order for Natural Selection to occur, these 3 conditions must be met:

  1) There must be genetic variation in a population (genetic variation creates different physical traits) 

  2) The variation must be heritable (can be passed on to the offspring)

  3) There must be differential reproductive success ( those with specific traits favored by the environment produce more offspring than those without the favorable trait) 

Lastly it's important to know that Natural Selection is NOT the only form of evolutionary change. 4 other mechanisms can also drive evolution. These are...

~ 1) Genetic Drift: causes traits within a population to change randomly.

   2) Gene Flow: causes traits to enter or leave a population due to organisms entering or leaving a population (emigration and immigration) 

   3) Mutation: modifies traits within a population by introducing new alleles (an allele is a version of a gene --> remember that each "trait" is produced from a specific gene in our DNA)

   4) Non-random mating.  

Hope this helps!

Perfect valentine to give while studying evolution! 

Tutor Review

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Great Place to Visit for a Spectacular View of the Pacific

Montana De Oro is a beautiful California State Park located 6 miles southwest of Morro Bay.  - very close to San Luis Obispo and Cal Poly where I went to college.  

ATP

What is ATP? Why is it considered energy? I thought we ate FOOD for energy?


ATP stands for Adenosine Triphosphate. Here's what the chemical structure looks like..

ATP generally consists of 3 negatively charged phosphate groups, an adenine (a purine nitrogenous base, just like in your DNA) and a ribose (a type of sugar monomer). 


ATP carries a special form of energy within the 3 phosphate groups called potential energy. Because each phosphate is negatively charged, and negative charges repel each other, energy is stored within the bonds of these 3 phosphates. Think of what might happen when a phosphate group is broken off. Do you think it would be a favorable reaction? Of course it would be! Those negative phosphate groups do NOT like being grouped together, thus if one phosphate is broken off, making Adenosine Diphosphate (ADP), the negative charges left can spread out more, repelling each other less. 


When a phosphate group is broken off ATP, making ADP, about 7.3 kilocalories (kcal) of energy per mole of ATP is released. What is this energy used for? Pretty much for all cellular functions! For instance, ATP can be used to move molecules, pump ions, even help a cell in moving itself. Imagine a sperm cell, that flagella needs a LOT of ATP in order to continue to whip back and forth. 


But if we use ATP for energy, why is it said that we eat food for energy? We need food in order to make ATP. Glucose, a sugar monomer, is the most favorable molecule to make ATP in a cell. ATP is made from glucose in a process called cellular respiration. However, if glucose is not available (perhaps you haven't eaten any carbohydrates in awhile) then other major molecules from food can be used to make ATP as well - like lipids (fats) or if your body is desperate, proteins. 

Cellular Respiration and Photosynthesis - The BIG Picture

Most likely on your finals your teachers will ask you to compare photosynthesis and cellular respiration. How DO they compare??

First write out their chemical formulas:

Cellular Respiration: C6H12O6 (glucose)+6O2 --> 6H20+6CO2+ATP

We breath in Oxygen and break down glucose (a sugar monomer) to provide our cells with energy in the form of ATP while breathing out Carbon Dioxide as a byproduct 

Photosynthesis: 6CO2+6H20+Sunlight --> C6H1206(glucose)+6O2

Plants take in Carbon Dioxide and use sunlight to convert six of them into a glucose molecule, giving off oxygen as a byproduct  

Do you see how the reactants (the left side of the equation) of one formula is pretty close to the products (the right side of the equation) of the other formula?  

Cellular Respiration and Photosynthesis are opposite chemical reactions! 

Now lets compare these two in several contexts.. 

In terms of the atmosphere...

- Photosynthesis INCREASES Oxygen concentration and DECREASES Carbon Dioxide concentration

- Cellular Respiration DECREASES Oxygen concentration and INCREASES Carbon Dioxide concentration 

In terms of an Anabolic or Catabolic reaction..

(An Anabolic reaction is a chemical reactions that BUILDS UP a molecule, where as a Catabolic reaction is a chemical reaction that BREAKS DOWN a molecule)

- Photosynthesis is a Anabolic reaction (builds a glucose molecule)

- Cellular Respiration is a Catabolic reaction (breaks down a glucose molecule to make ATP)

In terms of an Endothermic or Exothermic reaction..

(An Endothermic reaction requires energy to occur, where as an Exothermic reaction gives off energy)

-Photosynthesis is an Endothermic reaction as it requires energy from sunlight to occur

-Cellular Respiration is an Exothermic reaction as the product is ATP (energy)

By writing the chemical formula for both these reactions at the top of your paper, the answer for these questions will be right there! Keep referring back to them to look and see what molecules remain on the "reactants" side and the "products" side. 

Now here's a question for ya..

Ancient earth had very low levels of Oxygen in the atmosphere but very high levels of Carbon Dioxide. How do you think Oxygen concentration increased so lifeforms like humans could live on earth??

It's That Time of Year Again..

FINALS WEEK!

For all of you that have a biology final coming up, good luck! If you need extra help studying I'm here as well. 

Here's a breakdown of major topics you'll most likely be quizzed on for your biology finals..

- Cells and their organelles (What do plant cells have that animal cells do not?)

- Macromolecules: Proteins, Carbohydrates (sugars), Nucleic Acids, Lipids

- DNA: Structure, function, how it replicates

- Meiosis vs Mitosis

- Genetics: Who is Gregor Mendel? How do you make a punnet square and what does it tell you?

- How proteins are made: Transcription and Translation

- Evolution: Darwin who? 

- Photosynthesis vs Cellular Respiration 

- Plants and the Human body  

Carbon Fixation

What's one of the main concepts of photosynthesis? Carbon fixation!


Carbon fixation is when atmospheric Carbon in the form of Carbon Dioxide is converted into the tissues of plants in the form of glucose (through photosynthesis) and stored as either starch or cellulose. Carbon fixation "fixes" atmospheric Carbon into a more useful biological form.


If it weren't for photosynthesis and Carbon fixation, a lot of the Carbon on earth would be stuck in the atmosphere!


Now here's a question for ya...


If plants take in Carbon in the form of Carbon Dioxide and convert it to glucose, how is Carbon then released back out into the atmosphere??  

SPONCH?

Need a quick and easy way of remembering the most common elements in living organisms? 

Remember the word : SPONCH - S(Sulfur) P(Phosphorus) O(Oxygen) N(Nitrogen) C(Carbon) H(Hydrogen)

Better yet, SPONCH also tells ya which elements are the most common by reading it backwards (beginning with Hydrogen as most common, next to Carbon and so on)