Chemical Compounds in Cells and The Cell in its
Environment
Slide 2
Elements and Compounds What is an element? An element is any
substance that cannot be broken down into simpler substances The
smallest unit of an element is an atom. All living things include
carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. What is
a compound? A compound is made up of two or more elements. Carbon
dioxide is a compound. What elements make up carbon dioxide? Carbon
and oxygen
Slide 3
Organic and Inorganic Compounds o Organic compounds contain
carbon, inorganic compounds do not. o Carbohydrates, lipids,
proteins and nucleic acids all contain carbon. o These are common
compounds in the food we eat.
Slide 4
Organic Compounds Carbohydrates- energy rich Sugars are
produced during the food making process in plants Fruits and some
vegetables have high sugar content Lipids- energy rich Fats, oils
and waxes are lipids Cell membranes are made of lipids
Slide 5
More Organic Compounds What do birds feather, a spiders web and
your finger nail have in common? They are all made of protein.
Proteins are made up of amino acids There are 20 common ones that
combine to form thousands of different proteins. Much of the
structure and many of the organelles of cells are made up of
proteins.
Slide 6
Water Most chemical reactions within cells could not take place
without water. Water helps cells keep their size and shape. Water
helps keep the temperature of the cell from changing rapidly.
Slide 7
The Cell in Its Environment The cell membrane separates the
cell from the outside environment. The cell membrane is selectively
permeable. This means some substances can pass through while others
cannot.
Slide 8
Diffusion Diffusion is the main method by which molecules move
across the cell membrane. In diffusion, molecules ALWAYS move from
an area of higher concentration to an area of lower
concentration.
Slide 9
Osmosis Osmosis is the diffusion of water through a
semipermeable membrane. Cells depend on osmosis because, they
cannot function properly without water. Why cant people drink large
amounts of salt water?
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Active Transport Passive transport if the movement of dissolved
material through the cell membrane without using cellular energy
(high to low). Active transport requires cellular energy (low to
high). This can be done in 2 ways. Transport proteins pick-up
method Engulfing
