1. Chapter 6 Section 4: The building Blocks of life Ms Su’ad

2. Organic chemistry
Carbon is an essential element for almost all biological molecules. Life on Earth is considered carbon-based.
Scientists have created an entire branch of chemistry, ‘organic chemistry’ to the study of compounds containing carbon.
Living things on our planet are carbon-based because most of the molecules in them are chains of carbon atoms linked together.

3. Organic Chemistry
Carbon has four electrons in its outer energy level. One carbon atom is able to form 4 covalent bonds with other atoms. These covalent bonds enable the carbon atoms to bond to each other, which makes a variety of important organic compounds.

4. macromolecules
Carbon atoms can be joined to form carbon molecules. Most cells store small carbon compounds that are building blocks for large molecules.
Macromolecules – large molecules that are formed by joining smaller organic molecules together.
The smaller molecules are called monomers.
The larger molecules are called polymers. They are repeating units of monomers and linked together by covalent bonds.

5. Macromolecules

6. Macromolecules
Biological macromolecules are organized into four major categories:
Carbohydrates
Lipids
Proteins
Nucleic Acids

7. Carbohydrates
Carbohydrates – compounds composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1.
The general formula for a carbohydrate is CH20.
Two types of carbohydrates: Simple and Complex
Simple carbohydrates include:
Monosaccharides – carbohydrate simple sugars that play a central role as an energy source for organisms. It is made up of 1 molecule of sugar.
Ex. Glucose and fructose
Disaccharides – also an energy source. They are made of up 2 sugar molecules.
Ex. Sucrose (table sugar) and lactose

8. Carbohydrates Complex Carbohydrates include:
Polysaccharides – longer carbohydrate molecules (100s).
Ex. Glycogen – important energy storage form of glucose that is found in the liver and skeletal muscle.
When the body needs energy between meals or during physical activities, glycogen is broken down into glucose.
Carbohydrates have important functions in biology. In plants, a carbohydrate called cellulose provides structural support in cell walls.
Cellulose is made of chains of glucose linked together into tough fibers, which makes them perfect for structural roles.

9. Carbohydrates

10. lipids
Lipids – molecules made mostly of carbon and hydrogen that make up the fats, oils, and waxes.
The primary function of lipids is to store energy. Organisms need lipids to function properly.
Triglycerides - a fat if it is solid at room temperature and an oil if it is liquid at room temperature. They are stored in the fat cells of the body.

11. LIPIDS
Lipids have fatty acid tails made up of carbon and hydrogen by single or double covalent bonds.
Single bond - saturated fat
Double bond – unsaturated fat
More than one double bond – polyunsaturated fat

12. proteins
Proteins – compound made of small carbon compounds called amino acids. They are a primary building block of living things.
Amino Acids – small compounds that are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur. All amino acids share the same general structure.
Amino acids have a central carbon atom and then 4 covalent bonds around it.
One bond is with hydrogen
One bond with an amino group (-NH2)
One bond with a carboxyl group (-COOH)
One bond with a variable group (-R)
The variable group is what makes each amino acid different because there are 20 different variable groups, and proteins are made of different combinations of all 20 different amino acids.

13. Proteins
Proteins make up about 15% of your total body mass and are involved in nearly every function of your body.
Your muscles, skin, and hair are made up of proteins.
Your cells contain about 10,000 different proteins. They are responsible for transporting substances into, out of, and between cells. They are responsible for communication signals, the speed of chemical reactions, and they control the growth of cells.

14. Nucleic acids
Nucleic Acids – complex macromolecules that store and transmit genetic information. Formed by chains of nucleotides.
Nucleotides – smaller repeating subunits of carbon, nitrogen, oxygen, phosphorus, and hydrogen atoms.
There are 6 major nucleotides, all of which have 3 main units – a phosphate, a nitrogen base, and a ribose sugar.

15. Nucleic Acids

16. Nucleic acids
There are 2 types of nucleic acids found in living organisms: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
DNA contain the sugar deoxyribose.
RNA contain the sugar ribose.
In DNA and RNA, the sugar of one nucleotide bonds to the phosphate of another nucleotide. The nitrogen base that sticks out from the chain is available for hydrogen bonding with other bases in other nucleic acids.

17. DNA and RNA Structure

20. Question?