1. Unit 4- Biochemistry, Energy, & Enzymes
4a- Chemistry + Carbon Compounds

2. Chemistry Review What makes an atom stable?
8 valence electrons; full outer energy level, or shell
What can an atom do to become stable?
Form bonds with other atoms

3. Chemistry Review Two types of bonds?
Ionic Bonds: attraction of oppositely charged ions
Covalent Bonds: form by sharing electrons; causes the outer energy levels to overlap

4. Chemistry Review
Bonds between atoms are built and broken causing substances to combine and recombine as different molecules during chemical reactions.
Essential functions of a cell involve chemical reactions that take place between many different types of molecules
All of the chemical reactions within a cell are referred to as the cell’s metabolism.

5. Building Blocks of Cells
Living things are organized…
All organisms are composed of organic molecules
Organic Molecules- contain carbon atoms

6. The Role of Carbon A carbon atom has 4 electrons in its valence shell.
Carbon can form covalent bonds with as many as 4 other atoms.
Can also bond with other carbon atoms to form a single, double or triple bond (sharing 1, 2, or 3 electrons)
Allows carbons to form straight chains, branched chains, or rings
Tendency of carbon to bond with itself results in enormous variety of organic compounds

7. Large Carbon Molecules (Biomolecules, Macromolecules)
Most organic molecules are made of smaller units (monomers) that bond to form larger molecules (polymers)
Energy is stored in the bonds that link these units together
The amount of energy varies with the type of molecule formed.
Polymer: a molecule that consists of repeated, linked units.
Units may be identical or structurally related
Lipids are not polymers, carbs, proteins, Nacids are
Polymer- identical units- like a metal watch wristband, or similar- like the beads that make up a multicolored necklace

8. Large Carbon Compounds
Example: Starches are complex carbohydrates formed by long chains of simple sugars, like glucose
Glucose= monomer; Starch= polymer
Different functional groups

9. Molecules of Life
There are four types of organic compounds necessary for life (aka biomolecules)
Carbohydrates
Lipids
Proteins
Nucleic Acids

10. Carbohydrate Structure
Contain: Carbon, Hydrogen, & 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)
Simple sugars can bond together to make larger, more complex carbohydrate molecules

11. Role of Carbohydrates In Plants
Carbohydrates are synthesized during the process of photosynthesis
The plants then:
Use them as a source of energy
Store them in the cells.
Carbs are important as an energy source for all organisms

12. Role of Carbohydrates In Animals
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
Once inside the cells, they are used as fuel in the process of cellular respiration, releasing energy that 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.

13. Functions of Carbohydrates
Energy Source
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
An important source of fiber for animals to stimulate the digestive system
The C, H, & O that make up carbohydrates serve as raw materials for the synthesis of other small organic molecules, such as amino acids & fatty acids.
Our bodies cant breakdown cellulose into individual sugars. Helps move food along by stimulating contractions of the smooth muscles that form walls of digestive organs

14. Lipids Contain: Carbon, Hydrogen, & Oxygen
Includes fats (triglycerides), phospholipids, steroids, & waxes
A triglyceride is a lipid made up of a glycerol & 3 fatty acids
The high number of C-H bonds makes lipids very energy rich.
glycerol
three fatty acids

15. Role of Lipids
Fats
Important to organisms for energy when carbohydrates are scarce, but when there is no shortage of food, stored fat accumulates.
Functions:
providing long-term energy storage
cushioning of vital organs
insulation for the body
Fats are insoluble in water.

16. Role of Lipids Phospholipids Steroids Waxes
Major component of cell membranes.
Steroids
Can serve as raw materials necessary for the production of some vitamins, some hormones, and cholesterol
Waxes
Lipids that form waterproof coatings for plants and animals
Phospholipid- hydrophilic phosphate head, hydrophobic fatty acid tail

17. Proteins Proteins are molecules composed of chains of amino acids
Contain: Carbon, Hydrogen, Oxygen, & Nitrogen & sometimes Sulfur
20 different amino acids
10 amino acids are made in the human body
Humans need to consume the other 10 amino acids from sources such as nuts, beans, or meat.
Failure to obtain enough of even 1 of the 10 essential AA’s results in degradation of the body’s proteins.
20 standard amino acids= encoded directly by codons in genetic code
Body doesn’t store excess AA’s like it does fat and starch—AA’s must be in food everyday
If the essentials arent included in our diet it can lead to organ damage & failure due to not being able to maintain and repair. Also will break down bodys proteins, like muscle, to obtain the one AA that is needed

18. Protein Structure Two amino acids bond to form a dipeptide.
This covalent bond is called a peptide bond
Polypeptide: long chain of amino acids
Proteins are composed of one or more polypeptides.
The sequence of amino acids determines the proteins shape & function.
~100,000 different proteins in the human body
Proteins are involved in almost every function in the human body

19. Role of Proteins
Proteins are the major structural & functional material of body cells. (workhorse molecules)
Because of the variety of shapes & structures of protein molecules, proteins have a wide variety of functions
Involved in almost every function in the human body
Functions:
Structural proteins- used for support such as connective tissue & keratin that forms hair & finger nails.
Transport proteins- move many substances throughout the body
Example: hemoglobin transports oxygen from the lungs to the other parts of the body to be used by cells in cellular respiration.

20. Hormone proteins- coordinate body activities
Example: insulin regulates the amount of sugar in the blood.
Contractile proteins- help control movement
Example: proteins in the muscles which help control contraction.
Enzymatic proteins- accelerate the speed of chemical reactions
Example: digestive enzymes break down food in the digestive tract.

21. Nucleic Acids Nucleic Acids are long chains of nucleotides
Nucleotides contain: Carbon, Hydrogen, Oxygen, Nitrogen, & Phosphorus
Nucleotides are made up of three parts
Five carbon sugar
Phosphate group
Nitrogen base

22. Function of Nucleic Acids
Carry and transmit genetic information
Two Types:
DNA – holds genetic code for an organism
RNA – makes a copy of DNA in order to make a protein

23. Calorie Comparison
Energy stored in organic molecules determines the caloric value
Lipids have the greatest chemical bond energy over carbohydrates & proteins
Calorie comparisons:
Proteins 4 Calories per gram
Lipids 9 Calories per gram
Carbohydrates 4 Calories per gram