Nice writing!  I wrote my suggestions below.  In general, you may want to keep an eye on when and when not to use the word "the" before a noun.

Cardiac Metabolism.

Our body obtains its energy from food. Through the digestive process, food is degraded and the body can obtains carbohydrates, fatty acids, and other relevant nutrients. As a perfect machine, in the body each organ in the body has a specific function, but not all needs the same amount of energy. In this sense;, the heart, brain and kidney are the organs metabolically most important.

In our body, the heart is the one responsible of for pumping blood throughout the body,.  With this movement, blood can transport nutrients and to remove waste from each organ and mainly, each cell. That cardiac activity justifies the high energetic requirement. Interestingly, the heart only needs energy to the relaxation process. [Do you mean the heart only needs energy while its relaxing? Consider re-phrasing the sentence]

During the cardiac metabolic metabolism, the heart uses lactic acid, carbohydrates, and fatty acids. Interestingly, 60-70 % 60-70% of cardiac energy is obtained from fatty acid and 30-40% from carbohydrates. In specific conditions like prolonged fasting [or you could say "a prolonged fast"], the heart uses in higher proportion fatty acids in higher proportion and can use lactic acid.

Although in under normal conditions, the heart has a set of enzymes necessary to process fatty acids. In metabolic diseases such as metabolic syndrome and diabetes, some metabolic enzymes has alterations in their expression or activity, situations that can exacerbate alterations in the heart.


Saludos desde México.

Obviously, you are a great writer already, so I will just make some minor style suggestions.  Also, I can tell that you read a lot in English.  You follow the conventions of English writing very well.  However, I would suggest that you glance at the conventions for starting quotations in a sentence.  Look in a novel and notice how they rarely start with ":", but instead start with either "," or nothing at all.

In the morning

The beginning of amorning in a working day on a workday is a special moment. First, I have a cup of coffee. It's a pleasure. When I feel more awake, I come in the children's bedroom and wake up them them up. The room is dark, a few a bit of light is coming through the window, and the mess is all over all the floor. Every day I say to my children with a sweet voice: "Good morning, children! It's time to wake up!" John, my youngest child, is always sleeping deeply and he complains: "Please dad, let me a few more..." He is a little stubborn, but he's a happy and nice boy too. I answer him: "Come on little boy, we don't want to be late at school!" Mary, my oldest child, is usually half asleep and she is the first to dress her. She is a clever and nice girl.

We have together the breakfast breakfast together and leave our house at a quarter to nine. The school opens at nine o'clock and I don't like my children are to be late. At the door of the school, we kiss and say to each other: "I love you, have a good day! Bye, bye!"

It's a good manner way to begin a fantastic day!

I live in Utah, USA, and I went on a vacation to NY for about one week.  It is a truly amazing city.  The whole city is alive, even at 3:00 in the morning.  I would also love to learn French and go to France.

Your post is perfect.  I only changed it to show some punctuation suggestions.  Here is how I would organize the sentences:

These are my plans to my future.

I'm from Colombia, and I'd like to visit NY and France.  For that reason, I'm studying English.  After that, I'll study French. With this page, I'd like to make friends and practice.

Welcome!  Felicitaciones por empezar!

Here are some suggestions:

Hello!, Everyone!!!

For muy me it is a pleausere pleasure have been to be here and i hope to improve my english!!!

Thanks new friends!

See you soon!

I'm glad to hear that you're watching TV and the news a lot.  Those are great ways to pick up how English is spoken.

RIGHT NOW

Hi, good evening

I am enthusiast (you could say "enthused", but "excited" sounds more natural) for my entry here every day. Today went was a normal day, I went at the cher church (you can just say "church" or "my church" without adding "the" before it)
I ate my lunch in the house from my ex-roommate. I ate spaghetti with chicken, the lunch was delicious.

Now I am watching tv TV, news in Cnn CNN, and I am practicing my english listening to the news.

I want to write more words but i am learning every day.

Good Night.

Here is are some suggestions for English.  They have widely varying sounds, but they're all great: The White Stripes, Arctic Monkeys, Van Morrisson, Ben Kweller, Bob Dylan, The Who, Sublime, Tracy Chapman, No Doubt

You will thank me later.  Happy listening!

Me encanta Julieta Venegas!