Inorganic ions

Question 1

What is a ion?

Answer 1

An atom or group of atoms that has an electric charge.

Question 2

What is a ion with a positive charge called ?

Answer 2

A cation

Question 3

What is an ion with a negative charge called ?

Answer 3

a anion

Question 4

What is a inorganic ion ?

Answer 4

A ion which does not contain carbon (there are a few exceptions to this rule ).

Question 5

Where are inorganic ions found ?

Answer 5

In solutions ,in the cytoplasm of cells and the body fluids of organisms

Question 6

How is a Ion’s role decided and what does its role determine ?

Answer 6

-its properties
-where its found in high or low concentrations but The concentration of certain ions can fluctuate and can be used in cell signalling and neuronal transmission

Question 7

what are hydrogen Ions ?

Answer 7

H+ (essentially protons )

Question 8

What does the concentration of H+ ions determine?

Answer 8

the pH

Question 9

Explain the relationship between H+ ions concentration and pH

Answer 9

There is an inverse relationship between the pH value and the hydrogen ion concentration
-The more H+ ions present, the lower the pH (the more acidic the solution)
-The fewer H+ ions present, the higher the pH (the more alkaline the solution

Question 10

What is the concentration of H+ ions important for and why ?

Answer 10

enzyme-controlled reactions, which are all affected by pH

Question 11

what are the issues with enzyme controlled reactions having a too low or high pH ,give an example ?

Answer 11

-The fluids in the body normally have a pH value of approximately 7.4

-The maintenance of this normal pH is essential for many of the metabolic processes that take place within cells

-Changes in pH can affect enzyme structure

For example, abnormal levels of hydrogen ions can interact with the side-chains of amino acids and change the secondary and tertiary structures of the proteins that make up enzymes
This can cause denaturation of enzymes

Question 12

WHat are the two versions of Iron atoms and what are they known as ?

Answer 12

-oxidation states
-Iron (II) ions, also known as ferrous ions (Fe2+)
-Iron (III) ions, also known as ferric ions (Fe3+)

Question 13

what do iron ions do that is important ?

Question 14

what is haemoglobin and Myoglobin ?

Answer 14

-Haemoglobin is the large protein in red blood cells that is responsible for transporting oxygen around the body

-Haemoglobin is made up of four polypeptide chains that each contain one Fe2+

-This Fe2+ is a key component in haemoglobin as it binds to oxygen

-When Oxygen is bound Fe2+ temporarily becomes a Fe3+ ion until oxygen is released

-Myoglobin in muscles functions in a similar way (it is an oxygen-binding protein) but is only made up of one polypeptide chain (containing one Fe2+)

Question 15

what is a sodium ion ?

Answer 15

Na+

Question 16

Why are Na+ ions important and explain this in terms of Villi ?

Answer 16

-Na+ is required for the transport of glucose and amino acids across cell-surface membranes (e.g. in the small intestine)
-Glucose and amino acid molecules can only enter cells (through carrier proteins) alongside Na+
-This process is known as co-transport
First, Na+ is actively transported out of the epithelial cells that line the villi

The Na+ concentration inside the epithelial cells is now lower than the Na+ concentration in the lumen of the small intestine

Na+ now re-enters the cells (moving down the concentration gradient) through co-transport proteins on the surface membrane of the epithelial cells, allowing glucose and amino acids to enter at the same time

Na+ is also required for the transmission of nerve impulses

Question 17

what are phosphate ions ?

Answer 17

PO43-

Question 18

what do phosphate ions do ?

Answer 18

attaches to other molecules to form phosphate groups

Question 19

what are phosphate groups a component of ?

Answer 19

essential component of DNA, RNA and ATP

Question 20

In DNA and RNA, the phosphate groups allow ….

Answer 20

individual nucleotides to join up (to form polynucleotides)

Question 21

why are phosphate groups a essential component in ATP?

Answer 21

In ATP, the bonds between phosphate groups store energy

These phosphate groups can be easily attached or detached

When the bonds between phosphate groups are broken, they release a large amount of energy, which can be used for cellular processes

Question 22

where are phosphates found ?

Answer 22

Phosphates are also found in phospholipids, which are key components of the phospholipid bilayer of cell membranes

Question 23

what is a calcium ion?

Answer 23

Ca2+

Question 24

give a detailed description of why Ca+ is important ?

Answer 24

Ca2+ is essential in the movement of organisms:
In synapses, calcium ions regulate the transmission of impulses from neurone to neurone

Ca2+ also stimulates muscle contraction
When an impulse reaches a muscle fibre, Ca2+ is released from the sarcoplasmic reticulum
This Ca2+ binds to troponin C, removing the tropomyosin from myosin-binding sites on actin
This allows actin-myosin cross-bridges to form when the muscle fibre contracts

Ca2+ can also help to regulate protein channels, which affects the permeability of cell membranes

Many enzymes are activated by Ca2+, making these ions key regulators in many biological reactions

The presence of Ca2+ is also necessary for the formation of blood clots (it is known as a clotting factor)