The Chemistry of Living Cells

1
The Chemistry of Living Cells

• Water and Organic Macromolecules

2
Water

• Water is a molecule that is essential to life as
  we know it here on Earth. It is a component of
  all living things and serves many functions.
  Water has many unique properties due to the
  nature of its molecular composition.

3
Water Molecule Polar Structureand Hydrogen
Bonding
Covalent bonds between hydrogen and oxygen
Positively charged hydrogen end
Due to the positively charged and negatively
charged regions on each molecule, the positive
region of one molecule becomes attracted to the
negatively charged region of another molecule
forming Hydrogen Bonds. The molecules stick
together.
Hydrogen Bonds
Negatively charged oxygen end
4
Important Properties of Water

• WATER STORES HEAT It requires much heat energy
  to raise the temperature of water one degree
  Celsius. Important in regulating the temperature
  of living things. It requires a long period of
  time for water to gain or lose heat energy.
  Important in regulating temperature, important to
  aquatic organisms.
• WATER IS A POWERFUL SOLVENT Many materials
  organic and inorganic will dissolve in water.
  Important in the role as a transport medium for
  living things. Animal blood and the sap of plants
  are primarily composed of water with other
  materials dissolved in it.
• WATER CLINGS TO ITSELF AND OTHER MOLECULES Water
  molecules due to their polar nature tend to stick
  to other substances. This property along with
  cohesion is responsible for capillary action and
  the formation of a meniscus in a glass tube.

5
Carbohydrates

• All carbohydrates are composed of carbon,
  hydrogen, and oxygen in a 121 empirical ratio.
  
• The general empirical formula for a carbohydrate
  is CH2O.
• If a carbohydrate has 5 carbons atoms,
  what would be its empirical formula?
• If a carbohydrate has 12 hydrogen atoms
  present, what would be its empirical formula?
• Most carbohydrates end with the suffix -ose

• C5H10O5

C6H12O6
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Functions of Carbohydrates

• Provide energy source
• Provide energy storage
• Structural Building Material

7
Lipids

• Lipids are complex molecules composed of carbon,
  hydrogen, and oxygen.
• Most lipids are non-polar and are hydrophobic.

8
Lipid Functions

• Energy storage Fats and oils.
• Waterproofing Waxes and oils
• Insulation Fat layers (blubber)
• Cushioning Fat layers (soles of your feet)
• Regulating metabolic processes Steroids
• Building component of cell membranes
• Phospholipids

9
Proteins

• Proteins are composed primarily of carbon,
  hydrogen, and oxygen. However, some contain
  sulfur.
• They are all composed of structural monomers
  called amino acids.
• Their differences from organism to organism is
  due to differences in the DNA which contains the
  instructions for their formation. Ex. Eye color,
  Blood type

10
Protein Functions

• Structure Building structural components of
  organisms
• (collagen, elastin, keratin, microtubules,
  microfilaments)
• Regulation of metabolic processes Hormones
  (insulin)
• Carrying out of metabolic processes Enzymes

11
Nucleic Acids

• Composed of carbon, hydrogen, oxygen, nitrogen,
  and phosphate
• Carriers of the genetic code (recipe book for
  proteins)
• Molecule responsible for heredity

12
Big Ideas

• Cells Must be Small efficient in moving
  materials/info into and out of the cell
• Cell Shrinky Dinks organelles (nucleus,
  cytoplasm, chloroplasts, cell membrane, cell
  wall, mitochondria)
• Plants and Animals compare/contrast, explain
  why they are different
• Water Lab cohesion/adhesion, polarity, hydrogen
  bonds, heat storage, good solvent
• Macromolecules carbohydrates, proteins, lipids,
  nucleic acids

13
Nucleotide Monomers

• Nucleic acids are composed of many monomers
  linked together by dehydration synthesis.
• These monomers are called nucleotides and are
  composed of a monosaccharide, a phosphate group,
  and a nitrogenous base.

14
Classes of Carbohydrates

• There are three major classes of carbohydrates
• 1. Monosaccharides (simple sugars) These are
  the monomers or building blocks for all other
  classes of carbohydrates. Examples glucose,
  fructose, galactose, and ribose.
• 2. Disaccharides are produced by joining
  two simple sugars. Examples sucrose (table
  sugar), maltose, lactose
• 3. Polysaccharides (complex carbohydrates)
  are produced by joining many monosaccharides
  together. Examples amylose, glycogen,
  cellulose, and chitin

15
Saturated vs. Unsaturated Fats

• When double bonds form in hydrocarbon chains it
  causes them to bend. In unsaturated fats this
  prevents the molecules from being able to stack
  or pack themselves tightly, thus they remain in
  a liquid state at room temperature such as oils.
  If the hydrocarbon chains are saturated, the
  chains are straight and pack themselves close
  together forming a solid at room temperature
  (animal fat, butter, tallow, lard).

16
Lipid Structure

• Alcohol (glyceral) covalently bonded fatty acid
  molecules