1.3.8 + 9 Minerals & Water

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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.

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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.

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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

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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.

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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 _________

cell wallsthe pigment

chlorophyllproteins

ATP, DNA

Plants absorb minerals through their roots

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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.

bones and teethhaemoglobin

osmotic balance water content

In the food they eat

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Minerals SummaryThey 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 fluidsSodium balances water content in cells

1.3.9 Water

Importance of Water to Organisms

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Need to know (Water)

Five good reasons why water is important for organisms.

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The three states of water

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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.

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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

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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

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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 …

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Learning check

What are the chemical properties of water?

• Universal solvent …

• Medium for metabolism …

• Reactant in chemical reactions …

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ENDWith thanks to the PDST biology support team for

the excellent 2011 resources DVD