Chapter 2 Cell Structure and Function
Lesson 1: Cells and Life (pages 42 – 48)
Basic Cell Substances
• What is a macromolecule?
o Large organic molecules that form when smaller
molecules are joined together.
o Many times made up of repeating subunits.
Basic Cell Substances
• Water:
o Essential to all life
o Makes up 70 percent of a
cell’s volume.
o Surrounds and insulates
cells to help maintain
homeostasis.
o Dissolves substances so
they can move in and out
of the cell.
Basic Cell Substances
• Water
o The chemical
properties of water
help it to dissolve
substances.
Positive end
Negative end
Basic Cell Substances
• Water
o The negative and positive ends
help water dissolve substances
such as salt.
https://www.youtube.com/watch?v=EBfGcTAJF4o
Basic Cell Substances
• Why is it important for cells to have
substances dissolved in water?
o Large Molecules – such as glucose - need to be dissolved
(in liquid form) in order to pass in and out of the cell.
Water
Glucose
Oxygen
Carbon Dioxide
Basic Cell Substances
• Four Basic Macromolecules that
make up living cells.
o Carbohydrate
o Protein
o Lipids
o Nucleic Acids
Macromolecules
Macromolecule
Description
Nucleic Acid
Macromolecules made
up of long chains of
nucleotides.
Protein
Macromolecules made
up of long chains of
amino acids.
Lipid
Carbohydrate
Examples
DNA or
RNA
amylase,
keratin
A large macromolecule cholesterol,
that does not dissolve phospholipids,
in water.
vitamin A
A macromolecule made
up of one simple sugar, sugar (fruit)
or a long chain of
and starches
sugars molecules
(bread)
Major role in living things
-Contain genetic information
that is passed from parent to
offspring.
-help cells communicate
-transport substances
-break down nutrients
-provide structural support
-help form protective barriers
-major part of cell membrane
-energy storage
-help cells communicate
-structural support
-energy storage
-help cells communicate
Carbohydrates
• Sugars and starches are both examples of
carbohydrates.
• What is the relationship between a sugar and a
starch?
Glucose (sugar)
Starch
Nucleic Acids
• Nucleic Acids - such as DNA and RNA are made up of repeating units called
Nucleotides.
Proteins
• Proteins are made up of repeating units
called amino acids.
Lipids
• Large macromolecules that are not soluble in
water.
• This inability to dissolve in water allows lipids
to form protective barriers in cells.
Lipids are the major
component in cell
membranes