Biological Elements Flashcards
(24 cards)
What are elements
Different types of atoms- distinguished by number of protons in nuclei
What are a living things composed of
Carbon (C), Hydrogen (H), Oxygen (O) and Nitrogen (N)
Phosphorus (P) and sulphur (S) also have an important role in biochemistry of cells.
How do atoms connect
With bonds
What are two or more atoms bonded called
Molecules
How does a covalent bond occur
Two atoms share a pair of electrons, electrons used to form bonds are unpaired and present in the outer orbitals of the atoms.
What are the simple rules of bonding (determined by number of unpaired electrons present in the outer orbitals of different elements)
-Carbon atoms can form four bonds with other atoms
-nitrogen atoms can form three bonds with other atoms
-oxygen atoms can form two bonds with other atoms
-hydrogen atoms can form one bond with another atom.
Difference between a cation and anion
-atom loses electron-positive-cation
-atom gains electron-negative-anion
How does ionic bonding happen
-one atom in the pair donates an electron and the other receives it. This forms positive and negative ions that are held together by the attraction of the opposite charges.
What are ions in solute called
Electrolytes
Roles of calcium ions Ca2+ (cation)
-Nerve impulse transmission
-Muscle contraction
Role of sodium ions Na+ (Cation)
-nerve impulse transmission
-kidney function
Role of potassium ions K+. (Cation)
-nerve impulse transmission
-stomatal opening
Role of hydrogen ions H+. (Cation)
-catalysis of reactions
-pH determination
Role of ammonium ions. NH4+. (Cation)
Production of nitrate ions by bacteria
Roles of nitrate ions NO3- (Anion)
Nitrogen supply to plants for amino acid and protein formation
Roles of hydrogen carbonate ions HCO3- (anions)
Involved in the transport of carbon dioxide in the blood
Roles of chloride ions. Cl- (Anions)
Involved in the transport of carbon dioxide in the blood as they are part of the chloride shift to balance positive charges
Roles of phosphate ions PO4. 3- (Anion)
-cell membrane formation
-nucleic acid and ATP formation
Roles of hydroxide ions OH- (Anions)
-catalysis of reactions
-pH determination
Elements in carbohydrates
Carbon, hydrogen and oxygen
Elements in lipids
Carbon, hydrogen and oxygen
Elements in proteins
Carbon, hydrogen, oxygen, nitrogen and sulfur
Elements in Nucleic acids
Carbon, hydrogen, oxygen, nitrogen and phosphorus
What are polymers
Biological molecules are polymers. Polymers are long-chain molecules made up by the linking of multiple individual molecules (called monomers) in a repeating pattern. In carbohydrates the monomers are sugars (saccharides) and in proteins the monomers are amino acids.