BIO 101 Flashcards
What is all matter composed of
What is the Bohr model?
Protons have a
positive charge (defined as +1 unit of charge)
Electrons have a
negative charge (defined as -1 unit of charge)
Neutrons have
zero charge
What is the mass of protons, neutrons, electrons?
● Mass of one proton or one neutron = atomic mass unit (amu) or 1 dalton, or 1.7 × 10–24 grams.
● Mass of one electron = 9 × 10–28— (0.0005 Da) , usually ignored
What is an element?
It is a pure substance containing only one kind of atom
● Elements are arranged in the periodic table.
● Elements in the same vertical columns have similar properties.
About 98% of the mass of most living organisms is composed of these six elements:
- carbon
- hydrogen
- nitrogen
- oxygen
- phosphorus
- sulfur
How do I find the number of protons?
The number of protons in the nucleus of an atom is called its atomic number: the atoms of a particular element all have the same number of protons. the atoms of different elements have different numbers of protons.
Atomic number is the 1st line in the element square on the periodic table.
What is a mass number?
It is the sum of the numbers of protons and neutrons present in the nucleus of an atom.
What are Isotopes?
Isotopes are versions of the same element. They have the same number of protons and electrons as the element but different mass numbers and number of neutrons. See picture 1
What are radioisotopes?
They are radioactive isotopes. They are unstable, they give off energy in the form of alpha, beta, and gamma radiation from the nucleus.
What determines how atoms will interact?
The number of electrons in the outermost shell of a particular atom determines how atoms will interact.
What describes the location of electrons in an atom?
Orbitals.
What is a chemical bond?
attractive force that links atoms together to form molecules. There are several different kinds such as :
● Covalent bonds, Ionic bonds, and Hydrogen bonds.
What are Covalent bonds?
What are Ionic bonds?
What are Hydrogen bonds?
What is Electronegativity?
Electronegativity is a measure of an atom’s ability to attract shared electrons to itself. On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group. It depends on the number of positive charges (protons) and the distance between the nucleus and electrons.
What four molecules are characteristic of living things?
- Proteins
- Carbohydrates
- Lipids
- Nucleic acids
What are monomers? And polymers? And how are they connected?
Monomers are small molecules, mostly organic, that can join with other similar molecules to form very large molecules, or polymers. A polymer is any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, which are multiples of simpler chemical units called monomers. Polymers make up many of the materials in living organisms and are the basis of many minerals and man-made materials.