AIM: WHAT ARE BIOMOLECULES? DO NOW : DEFINE WHAT A MOLECULE IS
AND GIVE AN EXAMPLE OF ONE.
Slide 2
Cells are made of biomolecules which are build from smaller
organic molecules containing 3 main chemical elements: carbon,
oxygen, and hydrogen (plus lots of other elements) An organic
molecule is any molecule containing Carbon (C) and Hydrogen (H)
elements combined with any other chemical elements. Examples :
Glucose (C 6 H 12 O 6 ) is organic, H 2 O is not organic, CO2
(carbon dioxide) is not organic.C H O
Slide 3
Chemical reactions inside cells join together small organic
molecules (monomers/building blocks) to form large molecules
(polymers/macromolecules/biomolecules) by a process called
dehydration synthesis. The 4 main macromolecules in cells are
Carbohydrates, Lipids, Proteins, and Nucleic Acids.
Slide 4
Carbohydrates Are made from simple organic molecules called
sugars Scientific name for sugar is saccharide. Major source of
energy. Most organisms break down glucose to release chemical
energy from it. Can provide structural support for some organisms.
Cell walls of plants are made cellulose (carbohydrate). Shells of
crabs and lobsters are made of chitin (carbohydrate)
Slide 5
Cell recognition -In complex organisms cells recognize
neighboring cells by carbohydrate molecules on the cell membranes.
One sugar molecule is called monosaccharide, two sugar molecules
linked together form a disaccharide molecule. Three or more sugar
molecules linked together form polysaccharide. All carbohydrates
consist of C, H, and O combined in a very specific ratio : 1:2:1
(Means that for every atom of Carbon there are twice as many
Hydrogen atoms and the same number of Oxygen atoms)
Slide 6
Common monosaccharide glucose (made by plants during
photosynthesis process) Common disaccharides sucrose (table sugar)
and lactose ( milk sugar that some people have intolerance to)
Common polysaccharides : Starch found in plants and consists of
hundreds of glucose molecules bonded together. We obtain starch
from the foods we eat and break it down during digestion into
glucose molecules. Glycogen found in animals. Extra glucose
molecules are assembled together for storage in a form of a
glycogen molecules.
Slide 7
Slide 8
Identify the following as mono-,di-, or polysaccharides: 1. 2.
3.
Slide 9
Lipids Group includes fats, waxes, steroids, and phospholipids
Main function is to store energy( can do it more efficiently than
carbohydrates) and control water movement (repel water) Consist of
long chains of carbon atoms bound to hydrogen atoms Built from
simpler molecules of fatty acids and Glycerol Examples of lipids
are oils, butter, cholesterol, ear wax.
Slide 10
Lipids are insoluble in water. What does this tell you about
some properties of those molecules ?
Slide 11
Slide 12
Proteins Provide structure and support, enable movement, aid in
transportation, and assist in chemical reactions Made of amino
acids ( building blocks) All amino acids have N atoms together with
C, O, and H. The body needs 20 amino acids to build all the
proteins it needs. Most of the amino acids we obtain from the food
we eat when we digest proteins.
Slide 13
The amino acids are linked together by peptide bonds This is
why proteins can be called polypeptides (if they have more then two
peptide bonds) or dipeptides ( if they contain two bonds) Examples
of proteins : Keratin (found in hair and nails) Hemoglobin ( found
in our blood, helps transport oxygen molecules)
Slide 14
Enzymes Large group of molecules which belongs to the protein
group Major function is to increase the rate of chemical reactions.
Called Catalysts (speed up reactions) Hold molecules close together
and in correct orientation speeding up their possibility of a
chemical reaction. Chemical Reactions A reactant the substance that
is changed A product a new substance that is formed Every chemical
reaction requires a minimum amount of kinetic energy. This amount
of energy is called Activation Energy. Chemical reactions can occur
only when the activation energy is available and the correct atoms
are aligned.
Slide 15
Name the reactants and the product in this reaction.
