Science is based on observations
A scientific community is made up of a group of people that study science, they usually work for universities, organizations, and private sector companies, scientists share their observations to compare notes.
Scientists keep track of things like:
Climate patterns, how many animals are in a habitat, habitat destruction, whether or not the same disease is in various parts of the world, whether or not something is alive, and much more.
How to know if SOMETHING is alive?
Sometimes it is not so clear, NASA has been working on missions to Mars for decades to see if there is life on Mars. The first spacecraft to land in Mars was Viking Lander 1, this happened July 20,1976.
What are signs of life?
The robots that have been sent to Mars to look for signs of life have arms that collect samples of possible signs of life.
Here are the five functional traits of living beings:
Living beings grow through cell division, single celled organisms grow in cell size.
Living beings produce new organisms by having the organs needed to reproduce, they usually produce genetically similar organisms that are not completely identical.
The maintenance of a relatively constant internal environment. Living organisms maintain a balanced temperature, ph, sugar and salt level, and water balance, we have many organs that help us maintain homeostasis.
Sense and respond to stimuli:
Living organisms move in response to what is happening, they might move away from the sun or towards the sun, they might move towards a food source or away from a predator.
Obtain and use energy:
Living beings consume food, or sunlight in the case of plants. They process the energy through metabolism where chemical reactions turn the energy into a usable form. Living being consume energy to power their daily activities.
PROCESS of Science
Scientists work in teams to analyze the samples that are collected by the missions to Mars:
A lot of the data analysis happens right there in Mars, a machine checks samples to see if there is oxygen or carbon dioxide (what we breathe out), the information is sent to NASA for analysis.
This is how we learn what elements are in the soil, an element is a chemically pure substance that cannot be chemically broken down, each element is made of a single type of atom, an atom is the smallest unit of an element.
The elements are organized in the periodic table
How small is an atom?
Nasa COntinues to look for life on mars
Looking for the molecules of life
A molecule is a group of Atoms that are bonded together
The main elements in biological molecules:
Carbon, Hydrogen, Nitrogen, Oxygen, and Sulphur
Carbohydrates: made of carbon, hydrogen, oxygen
Are the main source of food, sugars, starches
There are monosaccharides and polysaccharides
Lipids: made of carbon, hydrogen, oxygen, phosphorous, sulphur
Are fats, they are hydrophobic which means they repel water
Proteins: carbon, hydrogen, oxygen, nitrogen, sometimes sulphur
Are in all living organisms, they are made of chains of amino acids, there are 21 amino acids
Nucleic acids: carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Store and transmit genetic information, they are in DNA and RNA
Here are some examples of atoms bonding and forming molecules
Carbon forms covalent bonds, this involves sharing of electron pairs between atoms, carbon has four electrons that can form bonds so it can form multiple covalent bonds and be part of large molecules.
Macromolecules are large molecules:
âcarbohydrates, lipid, proteins, and nucleic acids.
âNucleic acids are made of nucleotide subunits that are linked
RNA and DNA are nucleic acids
The nucleotide subunits are ATCG:
Adenine, Thymine, Cytosine, and Guanine, RNA has Uracil while DNA does not
âDNA is a double helix while RNA is a single strand
These structures contain instructions to build proteins and molecules that make up living organisms
Now we can see DNA with an electron microscope
Author: Jazmin Gannon
A place to grow