1. Biochemistry of Cells

2. Uses of Organic Molecules
Americans consume an average of 140 pounds of sugar per person per year
Cellulose, found in plant cell walls, is the most abundant organic compound on Earth

3. Uses of Organic Molecules
A typical cell in your body has about 2 meters of DNA
A typical cow produces over 200 pounds of methane gas each year

4. Water Water is used in most reactions in the body
About percent of an organism is water
Water is used in most reactions in the body
Water is called the universal solvent

5. Water Properties
Polarity
Cohesiveness
Adhesiveness
Surface Tension

6. Properties of Water Polarity
Hydrogens and oxygen that make up a water molecule do not share electrons equally.
-the molecule has a slightly positive side and a slightly negative side (even though over all it is a neutral molecule)
-this makes the water molecule a POLAR MOLECULE
-this is why water
can dissolve so
many substances

7. Properties of Water Hydrogen Bonds
-Weak bonds that hold water molecules together (gives water a high heat capacity)
Cohesion
-Attractive force between two like particles
-Allows for surface tension of water
Adhesion
-Attractive force between two unlike substance (cohesion+adhesion=capillarity)

8. Carbon-based Molecules
Although a cell is mostly water, the rest of the cell consists mostly of carbon-based molecules
Organic chemistry is the study of carbon compounds

9. Carbon is a Versatile Atom
It has four electrons in an outer shell that holds eight
Carbon can share its electrons with other atoms to form up to four covalent bonds

10. Hydrocarbons The simplest carbon compounds …
Contain only carbon & hydrogen atoms

11. Carbon can use its bonds to::
Attach to other carbons
Form an endless diversity of carbon skeletons

12. The hydrocarbons of fat molecules provide energy for our bodies
Large Hydrocarbons:
Are the main molecules in the gasoline we burn in our cars
The hydrocarbons of fat molecules provide energy for our bodies

13. Shape of Organic Molecules
Each type of organic molecule has a unique three-dimensional shape
The shape determines its function in an organism

14. Functional Groups are:
Groups of atoms that give properties to the compounds to which they attach
Lost Electrons
Gained Electrons

15. Giant Molecules - Polymers
Large molecules are called polymers
Polymers are built from smaller molecules called monomers
Biologists call them macromolecules

16. Examples of Polymers
Proteins
Lipids
Carbohydrates
Nucleic Acids

17. This process joins two sugar monomers to make a double sugar
Linking Monomers
Cells link monomers by a process called dehydration synthesis (removing a molecule of water)
Remove H
H2O Forms
Remove OH
This process joins two sugar monomers to make a double sugar

18. Breaking Down Polymers
Cells break down macromolecules by a process called hydrolysis (adding a molecule of water)
Water added to split a double sugar

19. Macromolecules in Organisms
There are four categories of large molecules in cells:
Carbohydrates
Lipids
Proteins
Nucleic Acids

20. Carbohydrates Carbohydrates include:
Small sugar molecules in soft drinks
Long starch molecules in pasta and potatoes

21. Monosaccharides: Called simple sugar
Monomer of Carbohydrates
Called simple sugar
Include glucose, fructose, & galactose
Have the same chemical makeup, but different structural formulas C6H12O6
*isomers*

22. Monosaccharides Glucose is found in sports drinks
Fructose is found in fruits
Honey contains both glucose & fructose
Galactose is called “milk sugar”

23. Disaccharides A disaccharide is a double sugar
They’re made by joining two monosaccharides
Involves removing a water molecule (dehydration)

24. Common disaccharides include:
Sucrose (table sugar) glucose + fructose
Lactose (Milk Sugar) galactose + glucose
Maltose (Grain sugar) 2 glucose molecules

25. Polysaccharides Complex carbohydrates
Composed of many sugar monomers linked together
Polymers of monosaccharide chains

26. Examples of Polysaccharides
Starch
-A polysaccharide in plants, stored for energy (Potatoes and grains)
Glycogen
-A polysaccharide in animals, how animals store excess sugar, similar in structure to starch
Cellulose
-The most abundant organic
compound on Earth, major component of wood

27. Lipids Lipids are hydrophobic –”water fearing” Do NOT mix with water
Includes fats, waxes, steroids, & oils
FAT MOLECULE

28. Function of Lipids
Fats store energy, help to insulate the body, cushion and protect organs and protect plants from evaporation

29. Types of Fatty Acids
Unsaturated fatty acids have less than the maximum number of hydrogens bonded to the carbons (a double bond between carbons)
Saturated fatty acids have the maximum number of hydrogens bonded to the carbons (all single bonds between carbons)

30. Types of Fatty Acids Single Bonds in Carbon chain
Double bond in carbon chain

31. Triglyceride Monomer of lipids
Composed of Glycerol & 3 fatty acid chains
Glycerol forms the “backbone” of the fat
Organic Alcohol

32. Triglyceride
Fatty Acid Chains
Glycerol

33. Fats in Organisms
Most animal fats have a high proportion of saturated fatty acids & exist as solids at room temperature (butter, margarine, shortening)

34. Fats in Organisms
Most plant oils tend to be low in saturated fatty acids & exist as liquids at room temperature (oils)

35. Steroids
The carbon skeleton of steroids is bent to form 4 fused rings
Cholesterol
Cholesterol is the “base steroid” from which your body produces other steroids
Estrogen
Testosterone
Estrogen & testosterone are also steroids

36. Synthetic Anabolic Steroids
They are variants of testosterone
Some athletes use them to build up their muscles quickly
They can pose serious health risks

37. Proteins Proteins are polymers made of monomers called amino acids
All proteins are made of 20 different amino acids linked in different orders
Proteins are used to build cells, act as hormones & enzymes, and do much of the work in a cell

38. Four Types of Proteins
Storage
Structural
Contractile
Transport

39. 20 Amino Acid Monomers

40. Structure of Amino Acids
group
Carboxyl
group
Amino acids have a central carbon with 4 things bonded to it:
R group
1.Amino group -NH3
2.Carboxyl group -COOH
3.Hydrogen -H
Side groups
4.Side group -R
Serine-hydrophillic
Leucine -hydrophobic

41. Linking Amino Acids Cells link amino acids together to make proteins
(dehydration synthesis)
Dehydration Synthesis
Peptide bonds form to hold the amino acids together
Peptide Bond

42. Proteins as Enzymes
Many proteins act as biological catalysts or enzymes
Thousands of different enzymes exist in the body
Enzymes control the rate of chemical reactions by weakening bonds, thus lowering the amount of activation energy needed for the reaction

43. Activation Energy Diagram

44. Enzymes Enzymes are globular proteins.
Their folded conformation creates an area known as the active site.
The nature and arrangement of amino acids in the active site make it specific for only one type of substrate.

45. Enzyme + Substrate = Product

46. Factors effecting enzymes:
Temperature - Most human enzymes operate at 35-40OC. At lower temperatures, allosteric changes cannot occur. At higher temperatures, proteins (enzymes) can be denatured.
pH - Charged areas of an enzyme can be effected by [H+, OH-], thus reducing their action in high or low pH.
Activation Energy: As amount of substrate decreases, the rate of enzyme activity will decrease also

47. Primary Protein Structure
The primary structure is the specific sequence of amino acids in a protein
Amino Acid

48. Protein Structures Hydrogen bond Pleated sheet Polypeptide
(single subunit)
Amino acid
(a) Primary structure
Hydrogen bond
Alpha helix
(b) Secondary structure
(c) Tertiary structure
(d) Quaternary structure

49. Denaturating Proteins
Changes in temperature & pH can denature (unfold) a protein so it no longer works
Cooking denatures protein in eggs
Milk protein separates into curds & whey when it denatures

50. Changing Amino Acid Sequence
Substitution of one amino acid for another in hemoglobin causes sickle-cell disease 2 1 3 6 4 5
(a) Normal red blood cell
Normal hemoglobin 2 1 3 6 4 5
(b) Sickled red blood cell
Sickle-cell hemoglobin

51. Nucleic Acids Polymer that stores hereditary information
Contains information for making all the body’s proteins
Two types exist --- DNA & RNA
Monomer is the nucleotide

52. Nucleic Acids Nucleotide is made of 3 things
Nitrogenous base
(A,G,C, or T)
Nucleotide is made of 3 things
-a sugar, a phosphate group and a nitrogen base
Phosphate
group
Sugar
(deoxyribose)
Phosphate
Sugar
Base
Nucleotide

53. Bases Each DNA nucleotide has one of the following bases: Adenine (A)
Thymine (T)
Cytosine (C)
Adenine (A)
Guanine (G)
Thymine (T)
Cytosine (C)
Adenine (A)
Guanine (G)

54. DNA
Two strands of DNA join together to form a double helix

55. RNA – Ribonucleic Acid Contains a different sugar -Ribose sugar
Single strand
Nitrogenous base
(A,G,C, or U)
Uracil
It has the base uracil (U) instead of thymine (T)
Phosphate
group
Sugar (ribose)

56. Summary of Key Concepts

57. Macromolecules

58. Macromolecules