1. Biology 140 Chapter 2 Notes

2. Biochemistry Matter- substance which occupies space
Composes all living and nonliving things
Mass- amount of matter in an object
Weight-

3. Elements An element- Based on number of subatomic particles
92 naturally occurring elements
organized into the periodic table
Based on number of subatomic particles

4. Common Elements

5. Atoms Central nucleus Electrons Composed of atoms
Atom- smallest functional unit of an element
Atomic structure
Central nucleus
Protons -
Neutrons -
Electrons

6. Atom Diagram

7. Figure 2.1
140 Notes ICC Ms. Jacobson

8. Figure 2.2
140 Notes ICC Ms. Jacobson

9. Periodic table of the elements
Fig. 2.1
140 Notes ICC Ms. Jacobson

10. Molecules and compounds
Definitions
Molecule-
Compound- a molecule composed of atoms of 2 or more different elements
Ions and ionic bonds
An atom which has lost or gained electrons in a chemical reaction
Electrostatic interaction between a positive ion (cation) and a negative ion (anion) is called an ionic bond

11. Figure 2.3
140 Notes ICC Ms. Jacobson

12. Molecules and compounds, cont’d.
Covalent bonds
Each atom contributes one electron to the shared pair
More than one pair of electrons can be shared
Double covalent bond- 2 pairs shared
Triple covalent bond-3 pairs shared

13. Figure 2.4 Covalent Bonding
140 Notes ICC Ms. Jacobson

14. Hydrogen Bonds Figure 2.5a

15. Dissociation
When Ions dissolve in water, they form electrolytes and the water molecules

16. Figure 2.7
140 Notes ICC Ms. Jacobson

17. Chemical Reactions
Metabolism-All of the chemical reactions that occur in cells which
Reactants are the substances that participate in chemical reactions
Products-
Types of reactions
Synthesis- combining two or more reactants
140 Notes ICC Ms. Jacobson

18. Types of chemical reactions
Ex. ADP + P → ATP
Adenosine Diphosphate + phosphate becomes Adenosine Triphosphate
Decomposition Reactions-
Ex. ATP → ADP + P
140 Notes ICC Ms. Jacobson

19. Figure 2.8
140 Notes ICC Ms. Jacobson

20. Types of Reactions
Exchange Reactions- Elements from each of the reactants rearrange themselves as follows
CO2 + H2O → H+ + HCO3-
Energy- the capacity to do work
Potential-
Kinetic-
Mechanical-
Chemical-

21. Rate of Chemical Reactions
Properties of the Reactants
Concentrations
Temperature
Catalysts
Enzymes

22. Carbohydrates General structure Functions
Ratio of hydrogen atoms to oxygen atoms
is 2:1
Characteristic atomic grouping of H-C-OH
Functions
Principal energy source for cells
Structural components
140 Notes ICC Ms. Jacobson

23. Simple carbohydrates
Simple carbohydrates-monosaccharides and dissaccharides
Monosaccharides are simple sugars such as glucose (blood sugar), fructose, and lactose
Dissaccharides are 2 monosaccharides bonded together- an example is sucrose
(glucose+fructose)

24. Synthesizing a new disaccharide

25. Complex Carbohydrates
Polysaccharides- Carbohydrates made up of long chains of simple sugars
Cellulose
Structural carbohydrate in plants
“fiber”
Indigestible by human enzymes
Starches and glycogen
Quick energy storage
Starches are long chains of glucose
Glycogen is “animal starch”, composed of long chains of glucose in animal cells

26. Glycogen

27. Glycogen structure

28. Lipids General characteristics
Extremely diverse group including fats, oils, steroids, waxes, phospholipids
Common characteristic- nonpolar molecules which are insoluble in water
Contain more calories of energy per gram so are ideal energy storage molecules
Also function as structural components, insulation, cushioning of organs, and hormones

29. Lipids cont. Fats and oils
Oils tend to be liquid at room temperature and are usually of plant origin
Fats tend to be solid at room temperature and are usually of animal origin
Fats are often called triglycerides, as they are composed of one glycerol and 3 fatty acids
Fats are important in energy storage and insulation

30. Figure 2.12

31. Lipids cont.
Saturated and unsaturated fatty acids
Saturated have no double bonds between carbon atoms, and tend to be more solid at room temperature
Unsaturated have at least one double bond between carbons
Polyunsaturated have multiple double bonds- the more polyunsaturated the fatty acids, the more liquid the fat will be at room temperature

32. Figure 2.13

33. Lipids cont. Phospholipids Steroids
Attached phosphate gives “polarity”
Has a hydrophilic head and two hydrophobic tails
Important components of membranes
Steroids
“Skeleton” of 4 carbon rings
Cholesterol is a steroid which functions in membrane structure and hormone synthesis

34. Figure 2.14

35. Protein General characteristics
An amino acid has a central carbon atom with a carboxyl group (COOH) at one end and an amino group at the other (NH2)
Peptides
Bonds between amino acids are called peptide bonds

36. Fig. 2.24
140 Notes ICC Ms. Jacobson

37. Protein Organization
The shape of a protein molecule is critical to its function
Primary- shape held together by bonds between r groups chain of amino acids linked by peptide bonds
Secondary-coiling or folding of the primary structure to form a helix or a pleated sheet
Tertiary-

38. Figure 2.16
140 Notes ICC Ms. Jacobson

39. Proteins and Enzymes Proteins Enzymes
Denaturation- change the tertiary shape so the proteins do not function anymore Ex. Fried egg pH
Enzymes
Increase rate of chemical reactions by
the energy need to start a chemical reaction

40. Figure 2.17

41. Enzymes
Lock and Key-
The reaction is sped up because the enzyme and reactant are brought so close together
140 Notes ICC Ms. Jacobson

42. Figure 2.18
140 Notes ICC Ms. Jacobson

43. Nucleic Acids Two types- DNA and RNA Polymers of nucleotides
DNA- codes for the order of amino acids needed to make proteins
Ex. Hard drive
RNA-functions in synthesis of protein Ex. Flash drive
Polymers of nucleotides
Nucleotides are composed of a
140 Notes ICC Ms. Jacobson

44. Figure 2.20
140 Notes ICC Ms. Jacobson

45. Figure 2.19
140 Notes ICC Ms. Jacobson

46. Table 2.3