Presentation is loading. Please wait.

Presentation is loading. Please wait.

The Chemical Basis of Life

Similar presentations

Presentation on theme: "The Chemical Basis of Life"— Presentation transcript:

1 The Chemical Basis of Life

2 Organic Compounds Compounds containing carbon
(Actually contain carbon, hydrogen, and oxygen) Compounds that come from living things

3 Q1)Give two examples of organic compounds?
Sugar, Starch

4 Inorganic compounds Don’t contain carbon Don’t come from living things
Exceptions: Carbon dioxide, Carbon monoxide

5 Q2) Give 2 examples of inorganic molecules
Water, Salt

6 Unique bonding properties of carbon
Carbon has four electrons in its outer shell Carbon can form 4 covalent bonds Carbon can form complex molecules because of its ability to form 4 bonds at the same time

7 Chemistry of carbon Carbon can form Single covalent bonds
Shares 1 electron with one other atom. Double covalent bonds Shares 2 electrons with one other atom Triple covalent bonds (rare) Shares 3 electrons with one other atom (See examples of these bonds on the bottom of page 49)

8 Functional groups Common parts used molecule building Hydroxyl
-OH Carboxyl -COOH Amino -NH2

9 Monomers Simple building block molecules

10 Polymers Two or more monomers covalently bonded together.
Can be two or two thousand… Allow very large molecules to built with only a few basic parts.

11 Two chemical reactions used
Dehydration Synthesis Covalent bond is formed by the removal of water. Two monomers become joined together.

12 Dehydration Synthesis Reaction

13 Two Chemical Reactions Used
Hydrolysis Separation of two monomers by adding water and breaking the covalent bond

14 Hydrolysis Reaction

15 Carbohydrates Made from glucose molecules (sugars)
Carbohydrates are used by living things as a source of energy.

16 Monosaccharides Simple sugars Have the formula C6H12O6
Mono = one Saccharide = sugar Have the formula C6H12O6 Form rings when in water

17 Some Sample Monosaccharides

18 Q2) Where do people get glucose molecules?
Plants produce glucose during photosynthesis and animals get glucose by eating plants.

19 Disaccharides Di = Two Saccharide = sugar

20 Polysaccharides Two or more monosaccharides joined together by a covalent bond. The bond forms by a Dehydration Synthesis Reaction.

21 Four types of polysaccharides Made of Glucose

22 Starch Energy storage in plants

23 Glycogen Energy storage in plant seeds and short term energy storage in animals (1 day)

24 Cellulose Structural support in plants

25 Starch Vs. Cellulose STARCH CELLULOSE

26 Chitin Used in insect exoskeletons for structural support
Harvested and used as surgical stitches

27 Lipids Fats Oils Waxes Do not dissolve in water!!!

28 Molecules made from lipids
Fats Energy storage in animals and plant seeds A gram of fat stores more than twice as much energy as a gram of a polysaccharide.

29 Phospholipids Used in cell membranes
Separations between inside and outside of cell

30 Waxes Water proof molecules, many uses
Example: Waxy coating on leaves prevents water loss

31 Chemistry of Fats Glycerol 3 fatty acids
Chains of carbons with a carboxyl (acid) group at one end of each fatty acid


33 Two major types of fats Saturated fats – single bonds between carbon atoms Unsaturated fats – double bonds between carbon atoms

34 Q3) Which type of fat is unhealthy?
Saturated fats

35 What is the difference between fats and oils?
Fats are solid at room temperature and oils are liquids at room temperature.

36 Proteins The molecules that do the work inside of the cell.
Proteins are responsible for most of what happens inside of the cell.

37 Functions of a protein Movement Structural support Storage Defense
Regulation of chemical processes

38 What are two examples of things made of protein?
Enzymes (thousands of different types) Speed up chemical reactions Hemoglobin Used in red blood cells to transport oxygen

39 Structure of protein Amino acid The monomer of proteins
There are 20 different amino acids They can make billions of different proteins

40 Peptide Bond Holds these monomers together.
Formed by a dehydration synthesis reaction

41 Polypeptides Many amino acids bonded together making a long chain

42 How proteins are formed
Proteins are complexly folded polypeptide chains There are four levels of protein structure Each level of folding makes the protein more complex.


44 One change can be devastating

45 Stop for today.

46 The function of enzymes
Enzymes are Protein Catalysts Increase the speed of chemical reactions without being used up themselves. NOT CHANGED BY REACTION

47 Substrates The molecule that binds to the enzyme
These are the ones changed in the reaction

48 Enzyme-substrate complex
Active site The space where the substrate fits Lock and key Each enzyme is specific for one substrate!! 


50 Activation Energy Energy needed to get a reaction started.
Bonds are weakened by activation energy New bonds form to make products

51 Activation Energy Enzymes lower a reaction’s activation energy
A lower activation energy makes a reaction happen faster

52 Enzymes Catalysts in the body are enzymes
Enzymes work best at a certain temperature and pH

53 If the temperature or pH changes, the enzyme may not function.
If the bonds that hold the enzyme’s shape are changed, the enzyme will come apart. If this happens, the enzyme will denature.

54 Nucleic Acids Polymers which are used to store genetic information 

55 Nucleotide Monomer of nucleic acids Made from 1 sugar 1 base
1 phosphate


57 Two types of nucleic acids and their uses:
Deoxyribonucleic Acid DNA Stores genetic information and passes it on to the next generation Ribonucleic Acid RNA Takes information and uses it to make proteins

58 The information is stored in bases
The differences in the nucleotides is in the bases. The order of these bases makes up the genetic CODE.

59 DNA Bases There are four bases used in DNA Cytosine (C), Thymine (T) Adenine (A), Guanine (G)

60 RNA Bases There are four bases used in RNA Cytosine (C), Uracil (U)
Adenine (A), Guanine (G) Thymine is replaced by Uracil in RNA

Download ppt "The Chemical Basis of Life"

Similar presentations

Ads by Google