chemical elements and water n.
Skip this Video
Loading SlideShow in 5 Seconds..
Chemical Elements and Water PowerPoint Presentation
Download Presentation
Chemical Elements and Water

Loading in 2 Seconds...

play fullscreen
1 / 33

Chemical Elements and Water - PowerPoint PPT Presentation

  • Uploaded on

Chemical Elements and Water. Sections 3-1 & 3-2 & IB Topic 3.1. Many elements occur frequently in living organisms or are of use in metabolic processes. The most frequently occurring elements in living organisms are…?.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Chemical Elements and Water' - azia

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chemical elements and water

Chemical Elements and Water

Sections 3-1 & 3-2 & IB Topic 3.1


Many elements occur frequently in living organisms or are of use in metabolic processes.

The most frequently occurring elements in living organisms are…?


Can you explain what

these symbols are?

What is this?

What are these




An unreactive (stable) atom has a full outer electron shell. The inner shell is ‘full’ with two electrons. Subsequent shells are ‘full’ with eight electrons.

Inner shell = 2

(full). Outer shell = 1

(not full – lose one!)

Inner shell = 2 full outer shell = 7 (not full – gain one!)



More electrons

Than protons

So negative ANION

e- moves


More protons

Than electrons

So positive Cation


Carbon and hydrogen are the foundation of organic molecules – molecules found in living things.

The pH of a solution is a measure of the activity of dissolved H+ ions. A low pH (1- 6) signifies a high concentration of H+ ions. A high pH (8 – 14) signifies low H+ concentration.


A proton gradient in use.


Oxygen in respiration


Oxygen is also used in oxidation reactions: Oxygen is put in. For example, breaking phosphate from ATP to release energy in tissues.


Important nitrogen compounds:

  • Nitrogen: N2
  • Ammonium: NH4+
  • Nitrates: NO3-
  • Nitrites: NO2-
  • Urea: (NH2)2CO


Iron is an important micronutrient in living things.


Iron is often a limiting factor in plant productivity. Experiments of iron seeding can have dramatic effects, such as this phytoplankton bloom seen in the Baltic sea.


Calcium is an essential mineral in many species.

Horseshoe crab


Sulfur is found in some amino acids.

The ‘R’ group

Is the variable

  • It is also a reactant for chemosynthetic bacteria (chemoautotrophs) found in deep sea vents. These bacteria produce organic molecules from hydrogen sulphide, carbon dioxide and oxygen.

Where does the CO2 and O2 come from? Even though light is not directly part of the process, does chemosynthesis still reply on sunlight to an extent?


A ‘black smoker’ hydrothermal vent


Blood plasma

This is an example of active transport.

Cell Cytoplasm


Let’s start out with this animation

on the properties of water.


Cohesive properties of water

  • A single hydrogen bond is not very strong. A large number of hydrogen bonds are very strong. Each water molecule bonds with four others in a tetrahedral arrangement.

Cohesive properties of water

Can you do this?

Cohesion forms droplets. Surface tension keeps them spherical. Adhesion sticks them to the leaf.


Thermal properties of water

Water has a high specific heat capacity. This means that it takes a lot of energy for the temperature of water to change states. This is because there are so many H-bonds.

This all means that the temperature of water remains relatively stable. Most organisms are adapted to a narrow range of conditions. The slow heating and cooling of water are ideal for these organisms – there is less risk of extreme changes. Water moderates temperature changes.


Water as a coolant

It takes a lot of energy for water to change temperature. This means that it will heat or cool more slowly than air or land. So animals can use mud or water to cool off on a hot day.


Water as a coolant

Water makes up 70% of the body, including he blood. Because it is resistant to temperature change, cooler blood from some parts of the body can be circulated to other parts, cooling them down.


Solvent properties of water

Polar attractions cause water molecules to surround and isolate the solute molecules.


Solvent properties of water

Click on the link to try out another animation!


Water as a medium for metabolic reactions:

All metabolic reactions (reactions in living things) occur in solution meaning the reactants are dissolved.

Click to

See animation

What is a metabolic reaction?


Water as a medium for metabolic reactions:


Floating of Ice on Liquid Water

  • Ice floats in liquid water because hydrogen bonds in ice are more “ordered,” making ice less dense
figure 3 6

Figure 3.6

Hydrogen bond

Liquid water:

Hydrogen bonds

break and re-form


Hydrogen bonds

are stable


Water as a transport medium

Water is a good solvent (yup.. still saying that!): it dissolves nutrients, gases, and waste products. These can be carried in the circulatory system of animals, through xylem and phloem in vascular plants or through the water in soil or aquatic habitats.

Water can transport molecules across membranes in diffusion, as well as within the cell or interstitial (between-cell fluid).