Transcript 3.3 teacher Notes

Objectives
• What are the chemicals of life made from?
• What is the role of carbohydrates in cells?
• What do lipids do?
• What determines the function of proteins?
• What do nucleic acids do?
Section 3.3:
Carbon Compounds
Building Blocks of Cells
• The parts of a cell are made up of large,
complex molecules, often called biomolecules.
• Large, complex biomolecules are built from a
few smaller, simpler, repeating units arranged
in an extremely precise way.
• The basic unit of most biomolecules contain
atoms of carbon. Carbon atoms can form
covalent bonds with as many as four other
atoms.
Carbon
Bonding
Carbohydrates
• Carbohydrates are
molecules made of
sugars.
• A sugar contains carbon,
hydrogen, and oxygen
in a ratio of 1:2:1.
• Glucose is a common
sugar found in grape
juice.
Carbohydrates
• Glucose is a monosaccharide, or “single sugar.”
• Two sugars can be linked to make a disaccharide.
• Many sugars can be linked to make a
polysaccharide.
• Monosaccharides and disaccharides are considered
simple carbohydrates. Polysaccharides are
considered complex carbohydrates.
Checkpoint
• What are biomolecules and what are they made up of?
• What is the basic component of biomolecules?
– What type of bonds do they form and up to how many can they form?
• What are carbohydrates made up of?
– And what are these made up of?
• Place the following sugars in order of smallest to largest
sugars: polysaccharide, monosaccharide and disaccharide.
– Which ones are considered simple and complex?
Carbohydrates
• Cells use carbohydrates for
– sources of energy
– structural materials
– cellular identification
• Carbohydrates are a major source of energy
for many organisms, including humans.
Carbohydrates
• Chitin and cellulose are complex carbohydrates
that provide support.
• Chitin is found in the shells of insects and the cell
walls of mushrooms.
• Cellulose is found in the cell walls of plants.
• In a complex organism, cells recognize neighboring
cells by the short, branched chains of varying sugar
units on their outer surface.
Carbohydrates
Lipids
• Lipids are another class of biomolecules, which
includes fats, phospholipids, steroids, and
waxes.
• Lipids consist of chains of carbon atoms bonded
to each other and to hydrogen atoms.
– This structure makes lipids repel water.
• The main functions of lipids include storing
energy and controlling water molecules.
Lipids
• The main purpose of fats is to store energy.
• Fats can store energy even more efficiently than
carbohydrates.
• The cell’s boundary is made of phospholipids. The
structure of cell membranes depends on how this
molecule interacts with water.
• Waxes, found on the surfaces of plants and aquatic
bird feathers, help prevent evaporation of water
from the cells of the organism.
Checkpoint
Carbohydrates
• What are 3 cellular uses for carbohydrates?
• What are 2 examples of complex carbohydrates and
where are they found?
Lipids
• What are some examples of lipids?
• What do lipids consist of?
• What is 2 functions of Lipids?
• Where are waxes found and what is their function?
Proteins
• Proteins are chains of amino acids that twist and
fold into certain shapes that determine what the
proteins do.
• There are many types of proteins that perform many
types of functions.
• Proteins may be involved in
–
–
–
–
–
–
Structure
Support
Movement
Communication
Transportation
carrying out chemical reactions
Proteins
Amino Acids
• A protein is a molecule made up of amino acids,
building blocks that link to form proteins.
• Every amino acid has an amino group and a
carboxyl group.
– Units of amino acids can form links called peptide
bonds.
• The side group gives an amino acid its unique
properties.
– Twenty different amino acids are found in proteins.
Checkpoint
• What are proteins made up of?
• What determines their function?
• List several activities that proteins may be involved
in.
• What are the 3 parts that make up an amino acid?
– What is the name of the bonds that form in between
amino acids?
– How many different types are there?
Nucleic Acids
• A nucleic acid is a long chain of nucleotide units.
• A nucleotide is a molecule made up of three parts:
– a sugar
– a base
– a phosphate group.
• Nucleotides of deoxyribonucleic acid, or DNA,
contain the sugar deoxyribose.
• Nucleotides of ribonucleic acid, or RNA, contain the
sugar ribose.
Nucleic Acids
Hereditary Information
• DNA molecules act as “instructions” for the
processes of an organism’s life.
• DNA consists of two strands of nucleotides that
spiral around each other.
• RNA also interacts with DNA to help decode the
information.
• Nucleic acids store and transmit hereditary
information.
Nucleic Acids
Energy Carriers
• Some single nucleotides have other important
roles.
• Adenosine triphosphate, or ATP, is a nucleotide
that has three phosphate groups and supplies
energy to cells.
• Energy is released in the reaction that breaks off
the third phosphate group.
• Other single nucleotides transfer electrons or
hydrogen atoms for other life processes.
Checkpoint
• Nucleic acids are made up of?
– These are made up of
• 2 examples of nucleic acids are?
– What is the difference between these two?
• What is the job of DNA and what does it look like?
• What is the function of nucleic acids?
• What is the example of a nucleic acid that stores energy?
– How is energy released?
Summary
• Large, complex biomolecules are built from a
few smaller, simpler, repeating units arranged in
an extremely precise way.
• Cells use carbohydrates for sources of energy,
structural materials, and cellular identification.
• The main functions of lipids include storing
energy and controlling water movement
Summary
• Proteins are chains of amino acids that
twist and fold into shapes that determine
what the protein does.
• Nucleic acids store and transmit hereditary
information.