AP Literature & Composition WEEK 4: SEPTEMBER 21 ST - SEPTEMBER 25TH.
WEEK 4: Composition of Cells
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Transcript of WEEK 4: Composition of Cells
WEEK 4: Composition of CellsLEARNING OUTCOMESBy the end of this week, you should be
able to:Develop a knowledge and understanding of
the composition of cells.Describe the major groups of organic and
inorganic substances including carbohydrates, proteins, lipids, nucleic acids, water, minerals, vitamins.
Describe the general role of these substances in cell structure and function.
Chapter 3 Glossary Metabolism Catabolism Anabolism Water Cohesive Hydrogen bonds Hydrophilic Hydrophobic Monomers Polymers
Carbohydrates Monosaccharide Polysaccharide Lipids Trigylcerides Phospholipids Nucleic acids – DNA,
RNA Proteins Enzymes Minerals Vitamins
Organic Compounds Organic compounds all contain the
element carbon. They usually also contain hydrogen
and oxygen in varying quantities. They are often large molecules
(polymers), and are made of smaller sub-units (monomers) bonded together in various ways.
They all contain the elements C (______), H (________) and O (_______).
Nitrogen (N) and sulphur (S) are common in amino acids and nucleotides.
carbon hydrogenoxygen
Carbon
Oxygen
Hydrogen
Sulfur
Nitrogen
Organic Compounds
MONOMER POLYMER EXAMPLES
Monosaccharides (e.g. glucose) Polysaccharides Starch, glycogen,
cellulose
Fatty acids and glycerol Lipids Fats, oils, waxes
Amino acids Proteins (polypeptides)
Enzymes, hormones, structural proteins
Nucleotides Nucleic acidsDeoxyribonucleic acid
(DNA), ribonucleic acid (RNA)
Water Water is the predominant ______ in living
organisms. Water molecules are highly _______.
1. Draw and label a water molecule.2. Add a couple more water molecules to your
diagram and illustrate how they stick together.
solvent
cohesive
Carbohydrates The different properties of carbohydrates
relate to the way the glucose monomers have been linked together.
1. Copy table 3.3 from page 56 in your textbook.
Proteins Proteins contain nitrogen as well as C, H and O. There are 20 naturally occurring amino acids which
make up the many different types of proteins. Amino acids join together with a peptide bond. Two amino acids bonded together are called a
dipeptide. More than two amino acids bonded together are
called polypeptides.
1. Draw a polypeptide.2. Label a peptide bond and amino acid monomer.
Lipids Important in animals as they
contain about twice as much energy as polysaccharides.
Hydrophobic. Triglycerides are a common form
– they have one glycerol molecule and three fatty acid tails.
Phospholipids are the main constituent of plasma membranes. They have a phosphate group attached to the glycerol and two fatty acid tails.
Biological Roles of Lipids
Fat absorbs shocks. Organs that are prone to bumps and shocks (e.g. kidneys) are cushioned with a relatively thick layer of fat.
Phospholipids form the structural framework of
cellular membranes, e.g. the plasma membrane (above).
Lipids are concentrated sources of energy and
can be broken down (through fatty acid
oxidation in the mitochondria) to provide
fuel for aerobic respiration
Mitochondrion (false color TEM)
Waxes and oils, when secreted on to surfaces
provide waterproofing in plants and animals.
Biological Roles of Lipids
Lipids are a source of metabolic water. During respiration, stored
lipids are metabolized for energy, producing water and
carbon dioxide.
Fat absorbs shocks. Organs that are prone to bumps and shocks (e.g. kidneys) are cushioned with a relatively thick
layer of fat.
The white fat tissue (arrows) is visible in this
ox kidney
Stored lipids provide insulation in extreme
environments. Increased body fat levels in winter reduce heat losses to the
environment.
Nucleic Acids1. Draw Figure 3.12 from page 59 of your
textbook.2. Label the parts.3. Write down three differences between DNA
and RNA.