“Un arquero en el momento que estira todo su cuerpo para atajar la pelota” En esta actividad no solamente es necesaria la materia y la energía. La relación con el medio exterior es vital. En milésimas de segundo ingresa, se procesa y egresa información del cuerpo del arquero.
Entonces, pensando en esta situación, determinen:
1 La señal o estímulo
2 Receptor del estímulo
3 Centro de procesamiento del estímulo y producción de una respuesta
4 Órganos que llevan a cabo la respuesta.

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.