1. Chemistry and Biomolecules

2. Chemical Reactions
Bonds between atoms are built and broken causing substances to combine and recombine as different molecules during chemical reactions.
All of the chemical reactions within a cell are referred to as the cell’s metabolism.

3. The Role of Carbon
The carbon atom has four electrons available for bonding in its outer energy level.
When two carbons bond, they can form a single, double or triple bond (sharing 1, 2, or 3 electrons)
Carbons can form short chains, long chains, branched chains, or rings

4. Functional Groups -Give a family of molecules distinctive properties.
Hydroxyl -OH Organic compounds containing these groups are called alcohols. They are polar.
Carboxyl Group -COOH They release H+ in water and are referred to as organic acids.
Amines -NH2 They accept hydrogen ions from acids. (act as bases).
PO4 Phosphate group Used as the transfer of energy between organic molecules.

5. Organic Compounds
Organic compounds are any compound that contain carbon-hydrogen bonds.
There are four types of organic compounds necessary for life
Carbohydrates
Lipids
Proteins
Nucleic Acids

6. Carbohydrate Structure
Carbohydrates contain: Carbon, Hydrogen, and Oxygen
Structures:
Monosaccharides – 1 ring (simple sugars)
Glucose (cell’s primary source of energy)
Disaccharides – 2 rings
Sucrose (table sugar)
Polysaccharides – 3 or more rings (complex carbohydrates)
Amylose (component of starch)
Cellulose (structural carbohydrate in plants)

7. Role of Carbohydrates In Plants In Animals
Carbohydrates are synthesized during the process of photosynthesis
The plants then:
Use them as a source of energy
Store them in the cells.
In Animals
Carbohydrates are consumed as sugars, starches, and fiber
When complex carbohydrates are consumed, digestion breaks the bonds between the larger carbohydrate molecules so that individual simple sugars can be absorbed into the bloodstream through the walls of the intestines.
The bloodstream carries the simple sugars to cells throughout the body where they cross into the cells through the cell membrane.
Once inside the cells, simple sugars are used as fuel in the process of cellular respiration, releasing energy which is stored as ATP.
If an organism has a greater supply of carbohydrates than needed for its energy requirements, the extra energy is converted to fats and stored by the body.

8. Carbohydrates Functions Energy Source Energy Storage (short term)
Glucose in cells is the primary source of energy fuel for cellular respiration
Energy Storage (short term)
Glycogen in the liver of animals
Starch in the structures of plants
Structural Support
Cellulose forms cell walls in plants
Also an important source of fiber for animals to stimulate the digestive system

9. Lipids
Like carbohydrates, Lipids also contain Carbon, Hydrogen, and Oxygen
A triglyceride is a lipid made up of
a glycerol
three fatty acids
The high number of C-H bonds makes lipids very energy rich.
glycerol
three fatty acids

10. Role of Lipids
Fats are important to organisms for energy when carbohydrates are scarce, but when there is no shortage of food, stored fat accumulates.
When fats are consumed, the molecules are broken down during digestion so that individual glycerol and fatty acid molecules are absorbed into the bloodstream through the walls of the intestines.
The blood stream carries the glycerol and fatty acid molecules to cells throughout the body where the molecules cross into the cells through the cell membrane.
Once inside the cell, glycerols and fatty acids are stored for later use or used as fuel for cellular respiration if there are no carbohydrates available.
The process of cellular respiration releases the energy that is held in the chemical bonds of the glycerol and fatty acid molecules.

11. Lipids Functions Sources Energy Storage (long-term)
Animals in colder climates will store more fats to use as insulation as well as energy to keep warm
Stored fats are also used to cushion vital organs
Cellular Membrane Structure
A major component of the cell membrane is the phospholipid
Building Vitamins and Hormones
These help regulate our metabolism
Steroids ex.- cholesterol
Sources
Can be found in oils, meats, and nuts
steroid

12. More on Lipids Lipids include:
Fats (solids), oils (liquids), and waxes.
They are nonpolar
Saturated fatty acid: every carbon is joined by a single bond.
Unsaturated fatty acid: some carbons are joined by double bonds
Polyunsaturated fatty acids: several double bonds

13. Proteins
Proteins contain Carbon, Hydrogen, Oxygen, and Nitrogen and sometimes Sulfur
The building blocks of proteins are amino acids
There are 20 different amino acids
12 amino acids are made in the human body
Humans need to consume the other 8 amino acids from sources such as nuts, beans, or meat.

14. Role of Proteins
Proteins are more important as a source of building blocks than as a source of energy. Proteins can function as an energy source only if there is a shortage of carbohydrates or lipids.
Because of their structures, proteins serve different functions.
Structural proteins are used for support such as connective tissue and keratin that forms hair and finger nails.
Transport proteins transport many substances throughout the body such as hemoglobin which transports oxygen from the lungs to the other parts of the body to be used by cells in cellular respiration.
Hormone proteins coordinate body activities such as insulin which regulates the amount of sugar in the blood.
Contractile proteins help control movement such as proteins in the muscles which help control contraction.
Enzymatic proteins accelerate the speed of chemical reactions such as digestive enzymes which break down food in the digestive tract.

15. Nucleic Acids
Nucleotides are made up of Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus
Nucleic Acids are long chains of nucleotides
Nucleotides are made up of three parts
Five carbon sugar
Phosphate
Nitrogen base

16. Nucleic Acids Function Store information
DNA – holds genetic code for an organism
RNA – makes a copy of DNA in order to make a protein

17. Calorie Comparison
Energy stored in organic molecules determines the caloric value
Lipids have the greatest chemical bond energy over carbohydrates and proteins
This can be seen in their calorie comparisons
Proteins 4 calories per gram
Lipids 9 calories per gram
Carbohydrates 4 calories per gram