1. Biological Molecules & Water
Unit 4: Cells
Biological Molecules & Water

2. The Major Chemical Elements in Cells
Carbon C Atomic # 6
Hydrogen H Atomic # 1
Nitrogen N Atomic # 7
Oxygen O Atomic # 8
Phosphorus P Atomic # 15
Sulfur S Atomic # 16

3. Water The single most abundant compound found in living things.
One of the few compounds that are liquid at the temperature found over much of the Earth’s surface.
Expands as it freezes. Ice is less dense than water.

5. This means it is neutral.
pH Scale
Section 2-2
Oven cleaner
Bleach
Ammonia solution
Pure water has a pH of 7.
This means it is neutral.
Increasingly Basic
Soap
Sea water
Human blood
Neutral
Pure water
Milk
Normal
rainfall
Acid rain
Tomato
juice
Increasingly Acidic
Lemon juice
Stomach acid

6. Water is a universal solvent.
Figure 2-9 NaCI Solution
Section 2-2
Water is a universal solvent.
Cl-
Cl-
Na+
Na+
Water
Water

7. Water H2O A water molecule is polar.
It is a neutral molecule (10 protons and 10 electrons).
A water molecule is polar.
there is an uneven distribution of electrons between the oxygen and the hydrogen atoms.

8. Water is cohesive. Water is Adhesive
Cohesion is an attraction
between molecules of the same substance.
Water is Adhesive
Adhesion is an attraction between molecules of different substances.

10. Organic Macromolecules
Formed by a process known as polymerization.
Large compounds are built by joining smaller ones together.
Monomers = smaller units
Polymers = joined together
monomers.

12. Carbohydrates http://streaming. teachertube. com/viewVideo. php
Living things use carbohydrates as their main source of energy.
Made of carbon, hydrogen, and oxygen usually in a 1:2:1 ratio.
Monosaccharide
A single sugar molecule.
Glucose, galactose, and fructose.
Polysaccharides
Large macromolecules formed from monosaccharides.
Many animals store glycogen.
Plant use plant starch and cellulose.

14. Figure 2-13 A Starch
Section 2-3
Starch
Glucose

15. Lipids http://www.teachertube.com/viewVideo.php?video_id=43703
Lipids can be used to store energy.
important part of membranes and waterproof coverings.
Generally not soluble in water.
Made mostly from carbon and hydrogen.
Common categories are fats, oils, and waxes.

16. Lipids
Saturated – the fatty acids contain the maximum possible number of hydrogen atoms.
Unsaturated – The fatty acid contains at least one carbon to carbon double bond.
Polyunsaturated means that it contains more than one double bond.

17. Nucleic Acids http://www. teachertube. com/viewVideo. php
Nucleic acids store and transmit heredity, or genetic information.
Contain hydrogen, oxygen, nitrogen, carbon, and phosphorus.

18. Polymers assembled from nucleotides.
Nucleotides consist of three parts: a 5-carbon sugar, a phosphate group, and a nitrogenous base
There are two types of nucleic acids.
Ribonucleic Acid (RNA)
Deoxyribonucleic Acid (DNA)

19. Proteins http://www.teachertube.com/viewVideo.php?video_id=43704
Protein Functions:
control the rate of reactions
regulate cell processes.
form bones and muscles.
transport substances into or out of the cell.
fight disease.

20. Proteins Alanine Serine Contain nitrogen, carbon,
hydrogen, and oxygen.
Polymers of amino acids.
igure 2-16 Amino Acids
Proteins
Section 2-3
Amino group
Carboxyl group
General structure
Alanine
Serine

21. Figure 2-17 A Protein
Section 2-3
Amino
acids

22. Proteins have 4 levels of Organization
1st level is the sequence of amino acids in the protein chain,
2nd level is the amino acids can be twisted within the chain.
3rd level is the chain
itself may be folded.
4th level is if a protein has
more than one chain, each
chain has a specific
arrangement.