1. Chapter 2.3
Carbon Compounds

2. THINK ABOUT IT
In the early 1800s, many chemists called the compounds created by organisms “organic,” believing they were fundamentally different from compounds in nonliving things.
We now understand that the principles governing the chemistry of living and nonliving things are the same, but the term “organic chemistry” is still around.
Today, organic chemistry means the study of compounds that contain bonds between carbon atoms, while inorganic chemistry is the study of all other compounds.

3. A. Chemistry of Carbon
Carbon atoms have four valence electrons, allowing them to form strong covalent bonds with many other elements, including hydrogen, oxygen, phosphorus, sulfur, and nitrogen.
Living organisms are made up of organic molecules that consist of carbon and these other elements.

5. B. Macromolecules The four major groups are: carbohydrates lipids
Many of the organic compounds in living cells are macromolecules, or “giant biomolecules,” made from thousands of smaller molecules.
The four major groups are:
carbohydrates
lipids
proteins
nucleic acids

6. Macromolecules
The smaller units, or monomers, join together to form polymers.
The monomers in a polymer, which are large molecules, may be identical or different.

7. 1. Carbohydrates
Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1 : 2 : 1.
The breakdown of sugars, such as glucose, supplies immediate energy for cell activities.

8. a. Simple Sugars Single sugars are also known as monosaccharides.
Besides glucose, they include galactose, which is a component of milk, and fructose, which is found in many fruits.
Table sugar, sucrose, is an example of a disaccharide, a double sugar.

9. b. Complex Carbohydrates
3 or more monosaccharides bonded together are known as polysaccharides.
Many animals store excess sugar in the muscles as glycogen.
Plants use starch to store excess sugar. Found in grains, pasta, & potatoes.
Building blocks (or monomers) are monosaccharides.

11. 2. Lipids
Lipids are made mostly from carbon and hydrogen atoms and are generally not soluble in water.
One group of examples include fats, oils, and waxes.
Lipids can be used to store backup energy. Which contains more energy, fats or carbs?
- it’s fats! 1g fat = 9 cal & 1g carb = 4 cal
Another example is steroids. Some, such as hormones, serve as chemical messengers.

12. Lipids
Many lipids are formed when building blocks like a glycerol molecule combines with compounds called fatty acids.

13. Lipids
Some lipids are important parts of biological membranes and function as waterproof coverings.
Phospholipids contain hydrophobic tails to repel water

15. 3. Protein
Proteins contain atoms of nitrogen as well as carbon, hydrogen, and oxygen.
Proteins are polymers of molecules called amino acids
Perform many functions, such as catalyzing biochemical reactions (controlling their speed), transporting substances into or out of cells, and helping to fight disease.

16. Protein
Covalent bonds called peptide bonds link its building blocks, amino acids together to form a polypeptide.
A protein is a functional molecule built from one or more polypeptides.

17. Protein
Proteins have a primary structure of an amino acid sequence within a polypeptide.
Then, polypeptide chains get twisted and folded. For example, the protein shown, hemoglobin, is found in red blood cells.

19. 4. Nucleic Acids
Nucleic acids store and transmit hereditary, or genetic, information.
Contain the elements H, O, N, C, and
phosphorus (P).
Nucleic acids are polymers assembled from monomers (or building blocks) known as nucleotides.

20. Nucleic Acids
There are two examples of nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).
RNA contains the sugar ribose and DNA contains the sugar deoxyribose.

22. Protein More than 20 different amino acids are found in nature.
Amino acids differ from each other in a side chain called the R-group, which have a range of different properties.
More than 20 different amino acids are found in nature.
This variety results in proteins being among the most diverse macromolecules.

23. Macromolecules
Biochemists sort the macromolecules found in living things into groups based on their chemical composition.
Most are formed by a process known as polymerization (or dehydration synthesis), in which large compounds are built by joining smaller ones together.