3.1.8 Flashcards
What is an ion?
An atom or group of atoms with an electric charge
What is an ion with a positive charge called?
Cation
What is an ion with a negative charge called?
Anion
What is an inorganic ion?
An ion that doesn’t contain carbon
What is a hydrogen ion?
A proton
What does H+ concentration determine?
pH of solution
Describe the relationship between pH and H+ concentration
Inverse relationship
More H+ ions present= lower pH (more acidic)
Fewer H+ ions present= higher pH (more alkali)
How does the concentration of H+ affect enzyme controlled reactions?
Changes in pH can affect enzyme structure
Can interact with side chains of amino acids
Affects secondary and tertiary structures
Causes enzymes to denature
What is the pH of bodily fluids?
7.4
What are the 2 iron ions?
Iron (II) ions = Fe2+ -> ferrous ions
Iron (III) ions = Fe3+ -> ferric ions
How are iron ions used to transport oxygen?
Haemoglobin is a large protein in red blood cells responsible for transporting oxygen
Made up of 4 polypeptide chains, each containing one Fe2+
This binds to oxygen
How are sodium ions used in the body?
Co transport of glucose and amino acids across cell surface membrane
Na+ is actively transported out of epithelial cells that line the villi
Na+ conc now lower in epithelial cells than lumen of small intestine
Na+ reenters cells (moving down conc gradient) through co transport proteins
Allows glucose and amino acids to enter at same time
How are phosphate ions used in the body?
PO4^3− attaches to other molecules to form phosphate groups - essential component of DNA, RNA and ATP
In DNA and RNA phosphate groups allow nucleotides to join up
In ATP bonds between phosphate groups store energy- can be easily attached or detached to release energy which can be used for cellular processes
Also found in phospholipids- key component of phospholipid bilayer
