3.1 Biological Elements Flashcards
Chapter 3 - Biological Molecules
What are elements?
Different types of atoms
How are elements distinguished?
The number of protons in their atomic nuclei.
What are the four key elements all living things are primarily made of?
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
- Nitrogen (N)
What six elements are the most abundant in biological molecules?
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
- Nitrogen (N)
- Phosphorus (P)
- Sulfur (S)
What other elements also have an important role in biochemistry?
- Sodium (Na)
- Potassium (K)
- Calcium (Ca)
- Iron (Fe)
How do atoms connect with each other?
By forming bonds.
What is a molecule?
When two or more atoms bond together to form a complex.
When does a covalent bond occur?
When two atoms share a pair of electrons, the electrons are unpaired and present in the outer orbitals of the atoms.
What is bonding determined by?
The number of unpaired electrons present in the outer orbitals of different elements.
How many bonds can carbon atoms form with other atoms?
Four.
How many bonds can nitrogen atoms form with other atoms?
Three.
How many bonds can oxygen atoms form with other atoms?
Two.
How many bonds can hydrogen atoms form with other atoms?
One.
Why is life on this planet often referred to as being ‘carbon-based’?
Carbon, which can form four bonds, forms the backbone of most biological molecules.
What is an ion?
An atom or molecule in which the total number of electrons is not equal to the number of protons (like a charged atom).
