Chemistry - Week 1 Flashcards
Organisations of the Human Body - Week 1
What are the parts that make up the Organ System?
- Individual Organs
- Tissue
- Cells
- Organelles
- Macromolecules
- Molecules
- Elements
- Atoms
What are the 5 levels of Structural Organisation of the Human Body (from Basic to Complex)
- Chemical
- Cellular
- Tissue
- Organ
- System
- Organism (The Body)
What is an Element?
Elements make up all matter, both living and inanimate.
The smallest part of an element is an atom, and
An element is made of only one type of atom.
What is an Atom?
An atom is the smallest part of an element that has the characteristics of that element
It consists of three major subunits;
1. Protons
2. Neutrons
3. Electrons
What are the 3 major subunits of an Atom?
- PROTON has a positive electrical charge and is found in the nucleus of the atom.
- NEUTRON is electrically neutral or has no charge, and is also found in the nucleus
- ELECTRON has a negative charge and is found in the electron shell orbiting around the nucleus. These have a role in bonding.
What determines the type of bond an atom will form?
Based on the number of electrons in the outer shell of the atom.
It can get to this by either gaining, losing, or sharing electrons, and depending on which of these it does, determines what type of bond it is.
(An atom ideally wants eight electrons in its outer shell (Octet Rule))
What is a Chemical Bond?
Positive attracts Negative Electrons
Chemical bond is a force or attraction between positive and negative electrical charges.
It keeps two or more atoms closely associated with each other to form a molecule.
As a molecule (after chemical bonding) the physical characteristics are very different from when they were just elements (before chemical bonding).
Example of hydrogen and oxygen - As elements they are both gases, however when they form a molecule through chemical bonds, it turns into a liquid form - water.
What are Ionic Bonds?
Loss or Gain of Electrons
Ionic bonds involves the loss of one or more electrons by one atom, and gain of electrons by another atom.
What is an Ion?
An Ion is when an atom loses or gains one or more electron, its charge changes as the number of protons and electrons are no longer the same.
Cation - If it has a positive charge, or more protons than electrons
Anion - If it has a negative charge, or more electrons than protons
What are Covalent Bonds?
Sharing Electrons
Covalent bonds involve the sharing of electrons between atoms.
Explain how Oxygen forms a Covalent Bond
Oxygen atom has six electrons in its outer shell, and so needs two more electrons to be stable.
To do this it can share two electrons with another oxygen atom, also sharing two electrons. Together they form a molecule of oxygen gas.
Explain how Carbon forms Covalent Bonds?
The element carbon always forms covalent bonds. It can share its electrons with hydrogen, oxygen, nitrogen, or other elements.
It has four electrons to share with other atoms, and when carbons four electrons are shared with four atoms of hydrogen, which each share their one electron, it forms methane gas.
What are Disulfide bonds?
Disulfide bonds are covalent bonds formed between two atoms of sulfur, usually within the same large protein molecule.
These bonds are very important in maintaining the shape of a protein.
Example - Insulin it must have a very specific three-dimensional shape in order to function properly, and regulate blood glucose levels.
What are Hydrogen Bonds?
Opposites attracting
Hydrogen bonds occur when a hydrogen atom shares it’s one electron in a covalent bond with another atom, gaining a slight positive charge. This then might be attracted to an atom with a slight negative charge.
Hydrogen bonds are weak but important in maintaining shape.
It’s especially important in large molecules like DNA, where shape is integral to function.
Example - nitrogen or oxygen.
Hydrogen Bonds are important for the water in our body as it does things like making sure blood flows in a continuous stream in our vessels.
