1.3.8 + 9 Minerals & Water

Need to know (Minerals) Minerals required in small amounts Minerals used in three ways Form part of rigid body structures Form soft body tissues Function in cellular and body fluids State the requirements & use of any 2 minerals in plants. State the requirements & use of any 2 minerals in animals.

Minerals What are minerals? They are salts formed from the earth’s rocks. These mineral salts then dissolve in water and are absorbed by plants. Animals get their minerals by eating plants or other animals that contain them. NB Minerals are required by organisms in very small amounts.

Minerals and Plants Plants absorb minerals through their roots. They use: Calcium (Ca) to make cell walls Magnesium (Mg) to make the pigment chlorophyll Nitrates (N) to make proteins Phosphates (P) to make ATP, DNA

Minerals and Animals Animals get their minerals in the food they eat. They use Calcium (Ca) to make bones and teeth Iron (Fe) to make the pigment haemoglobin Sodium (Na) for the regulation of the osmotic balance (water content) of cells and the blood.

Learning check How do plants get their minerals? _________________________________ Plants use: Calcium (Ca) to make ________ Magnesium (Mg) to make _________ _________ Nitrates (N) to make ______ Phosphates (P) to make _________ Plants absorb minerals through their roots cell walls the pigment chlorophyll proteins ATP, DNA

Learning check How do animals get their minerals? ________________ Animals use: Calcium (Ca) to make ____________ Iron (Fe) to make the pigment __________ Sodium (Na) for the regulation of the _____________ (___________) of cells and the blood. In the food they eat bones and teeth haemoglobin osmotic balance water content

Minerals Summary They are required to: Form part of rigid body tissues Calcium in bones and cell walls Form certain pigments Iron is needed to make haemoglobin – the red pigment of blood Magnesium is needed to make chlorophyll – the green pigment in plants Regulate body fluids Sodium balances water content in cells

Importance of Water to Organisms

Need to know (Water) Five good reasons why water is important for organisms.

The three states of water

Water Cells and body fluids are made up of 70% to 95% Water Water has physical and chemical properties that have important effects on organisms.

Physical properties of water It is slow to heat up and cool down – kept at a fairly steady temperature – helps to keep a constant rate of metabolism. A good absorber of energy. It absorbs a lot of heat as it evaporates, so sweating and transpiration cools animals and plants. This helps to keep temperature steady. Participates in the movement of dissolved material in and out of cells. Controls cell shape. Strong adhesive and cohesive properties – transpiration

Chemical properties of water It is a universal solvent for transporting substances in blood or in plants The medium for metabolism i.e. chemical reactions take place in it within cells It is a reactant/product in chemical reactions e.g. photosynthesis, respiration and digestion

Learning check What are the physical properties of water? It is slow to heat up and cool down … A good absorber of energy … Movement of material … Cell shape …

Learning check What are the chemical properties of water? Universal solvent … Medium for metabolism … Reactant in chemical reactions …

END With thanks to the PDST biology support team for the excellent 2011 resources DVD