IBDP CORE>TOPIC 3.1>CHEMICAL ELEMENTS AND WATER
ASSESSMENT STATEMENT3.1.1 State that the most frequently occurring chemical elements in living things are carbon, hydrogen, oxygen and nitrogen.
3.1.2 State that a variety of other elements are needed by living organisms, including sulfur, calcium, phosphorus, iron and sodium. 3.1.3 State one role for each of the elements mentioned in 3.1.2. 3.1.4 Draw and label a diagram showing the structure of water molecules to show their polarity and hydrogen bond formation. 3.1.5 Outline the thermal, cohesive and solvent properties of water. 3.1.6 Explain the relationship between the properties of water and its uses in living organisms as a coolant, medium for metabolic reactions and transport medium. |
ANIMATIONS
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Introduction to Biochemistry
DAY 1
Watch the videos and answer the following questions.
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Create a word document for the chapter and answer these questions-
1. What do you mean by chemistry of life?
2. What are biologically important elements? Why are they called so?
3. Name four main biological elements.
3. State the role of each biologically important element.
1. What do you mean by chemistry of life?
2. What are biologically important elements? Why are they called so?
3. Name four main biological elements.
3. State the role of each biologically important element.
Role of elements
Sulphur (S): Found in certain amino acids (cysteine and methionine), allowing proteins to form disulphide bonds
Calcium (Ca): Found in bones and teeth, also involved in neurotransmitter release in synapses
Phosphorus (P): Component of nucleic acids and cell membranes
Iron (Fe): Found in haemoglobin (animals), allowing for oxygen transport
Sodium (Na): Involved in the generation of nerve impulses in neurons.
Calcium (Ca): Found in bones and teeth, also involved in neurotransmitter release in synapses
Phosphorus (P): Component of nucleic acids and cell membranes
Iron (Fe): Found in haemoglobin (animals), allowing for oxygen transport
Sodium (Na): Involved in the generation of nerve impulses in neurons.
DAY 2
WATER STATION LAB
You will be working in pairs. You will need a camera/smartphone for clicking pictures for the document to be submitted.
Watch the videos before coming for the lab.
In the lab-
There are 10 water stations showing various properties of water.
You have to identify the properties of each station and state how the property is significant for living organism.
You will be working in pairs. You will need a camera/smartphone for clicking pictures for the document to be submitted.
Watch the videos before coming for the lab.
In the lab-
There are 10 water stations showing various properties of water.
You have to identify the properties of each station and state how the property is significant for living organism.
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STRUCTURE OF WATER MOLECULE
3.1.5 Outline the thermal, cohesive and solvent properties of water.
Thermal properties-
Thermal capacity of water is high; therefore fluids containing water can carry away much heat;
The latent heat of vaporisation of water is high; water released onto the surface (sweat / saliva) carries away much heat by evaporation;
Cohesive properties-
Water molecules are strongly cohesive (they tend to stick to one another)
Water molecules will also tend to stick to other molecules that are charged or polar (adhesion)
Hydrogen bonds between water molecules make them cohesive/stick together; this gives water a high surface tension / explains how water rises up xylem
Solvent properties-
Water molecules are polar; this makes water a good solvent.
Water can dissolve many organic and inorganic substances that contain electronegative atoms.
This occurs because the polar attraction of large quantities of water molecules can sufficiently weaken intramolecular forces (such as ionic bonds) and result in the dissociation of the atoms.
Thermal capacity of water is high; therefore fluids containing water can carry away much heat;
The latent heat of vaporisation of water is high; water released onto the surface (sweat / saliva) carries away much heat by evaporation;
Cohesive properties-
Water molecules are strongly cohesive (they tend to stick to one another)
Water molecules will also tend to stick to other molecules that are charged or polar (adhesion)
Hydrogen bonds between water molecules make them cohesive/stick together; this gives water a high surface tension / explains how water rises up xylem
Solvent properties-
Water molecules are polar; this makes water a good solvent.
Water can dissolve many organic and inorganic substances that contain electronegative atoms.
This occurs because the polar attraction of large quantities of water molecules can sufficiently weaken intramolecular forces (such as ionic bonds) and result in the dissociation of the atoms.
3.1.6 Explain the relationship between the properties of water and its uses in living organisms as a coolant, medium for metabolic reactions and transport medium.
Acts as a coolant
Thermal capacity of water is high; therefore fluids containing water can carry away much heat;
The latent heat of vaporisation of water is high; water released onto the surface (sweating and panting in animals and transpiration in plants) carries away much heat by evaporation;
As a transport medium;water dissolves many substances; (this facilitates metabolic reactions)
Water remains liquid over much of the range of the Earth’s temperatures; as a fluid, water is used as a medium to transport biological materials; e.g. blood / lymph / other suitable example;
Water can transport heat; water currents disperse larval forms of marine species / sperm / eggs; water as a habitat;
Water is densest at 4°C / water freezes at the surface first; water bodies are thermally stable;
Water is transparent / light sensitive receptors can operate under water;
Water has a high surface tension / some animals can walk / live on the surface film;
Thermal capacity of water is high; therefore fluids containing water can carry away much heat;
The latent heat of vaporisation of water is high; water released onto the surface (sweating and panting in animals and transpiration in plants) carries away much heat by evaporation;
As a transport medium;water dissolves many substances; (this facilitates metabolic reactions)
Water remains liquid over much of the range of the Earth’s temperatures; as a fluid, water is used as a medium to transport biological materials; e.g. blood / lymph / other suitable example;
Water can transport heat; water currents disperse larval forms of marine species / sperm / eggs; water as a habitat;
Water is densest at 4°C / water freezes at the surface first; water bodies are thermally stable;
Water is transparent / light sensitive receptors can operate under water;
Water has a high surface tension / some animals can walk / live on the surface film;