Download Macromolecules

Macromolecules
(Building Blocks of Cell Organelles, Cells and You!)
The 4 major types of chemicals that make up our cell parts are carbohydrates, lipids, proteins and
nucleic acids. In this activity, you will research using the grade 11 text or the internet and build models
of simple macromolecules using ball and stick kits.
Ball & Stick Kits
Carbohydrates:
Yellow = Hydrogen
Red = Oxygen
Black = Carbon
Blue (3 holes) = N
1. A monosaccharide is the simplest form of a carbohydrate. It is called the subunit. Build it.
a. Give examples of monosaccharides.
Glucose, fructose, galactose
b. How do cells use monosaccharides?
As energy (mostly)
c. Describe in words and show using your model how 2 subunits link together to form
disaccharides. What is this chemical process called?
Dehydration synthesis/condensation:
2. Monosaccharides and disaccharides are stored in cells in longer chains called polysaccharides,
possibly due to the dangers of high levels of sugars or to allow the cells to pull in more sugar
passively. Give 3 examples of polysaccharides and their uses in cells.
Starch: Energy storage in plants
Cellulose: Cell wall construction material in plants and some fungi
Glycogen: Energy storage in animals
Lipids:
1. The “subunit” of lipids is a fatty acid. Build a small chain fatty acid. In your notes, illustrate the
two types of fatty acids.
2. Make some notes on how dietary fatty acids affect health.
Unsaturated fatty acids (mostly found in fish, fruit and vegetables) are easier to
break down, and help the body deal with extra cholesterol compared to saturated
fats (mostly found in meat, chicken and dairy products) in our bodies.
Cholesterol is type of fat that can build up in blood vessels and cause
atherosclerosis (plaques that harden and narrow vessels), which can lead to heart
attacks.
Etc.
3. Fatty acids can be attached (through dehydration synthesis) to different chemicals to perform
different functions in the cell. Find two different types of lipids and record their function and the
chemical that the fatty acids are attached to.
Phospholipids: Phosphate + 2 fatty acids: component of membranes in cells
Triglycerides: Glycerol + 3 fatty acids: energy source
Sterols: Ring structure + fatty acid: often used to make hormones
4. How is a fatty acid as a subunit in a lipid different from a monosaccharide as a subunit in a
carbohydrate?
A fatty acid is not attached to other fatty acids, but to a completely different
molecule, whereas monosaccharides connect to each other.
Proteins:
1. The subunit of the protein is an amino acid. Illustrate and build a general amino acid.
2. How many different amino acids exist? Identify where they differ.
20. At the R-group.
3. Show your partner how two amino acids form a peptide bond. What type of chemical reaction is
this?
Dehydration synthesis/condensation
4. Looking at an overall protein, would you say that amino acids more closely resemble
monosaccharides in carbohydrates or fatty acids in lipids? Explain.
You might argue either:
Carbohydrates because amino acids connect directly to each other with no
other molecule in between.
OR Fatty acids because they are not ring structures.
5. Describe the functions of proteins.
Proteins speed up chemical reactions (enzymes) making it possible for life to exist.
Proteins are involved in cell division and repair. Proteins can be used for energy
(last choice after sugars and lipids)
Nucleic Acids:
1. The subunit of a nucleic acid is a nucleotide. Identify the 3 parts of the nucleotide.
2. There are 5 different nucleotides. Name each and describe where they differ in their structure.
Guanine, Adenine, Thymine, Cytosine and Uracil. They differ in their Nitrogenous
base: Guanine and Adenine have a 2ring base (and are called Purines), while
Cytosine, Uracil and Thymine have a 1-ring base (and are called Pyrimidines).
3. There are 3 common types of nucleic acid. Name them and state their functions.
Deoxyribonucleic acid: control of cell activity (instructions to make and control
proteins)
Ribonucleic acid: instructions to make proteins (and ribosomes)
ATP: energy storage molecule for endothermic reactions in the cell.