Basic Chemistry

1
Basic Chemistry
Chapter 2
2
Chemistry of Life

• All life processes involve chemical reactions
  (clinical day)
• Ex. Ca in muscle contraction
• Na, K in nerve impulses

3
Matter

• anything that has mass and takes up space
• can you think of solids, liquids, and gases that
  might be found in the body?

4
Energy
link

• the capacity to do work
• No mass does not take up space
• Types
• Potential stored in bonds (chemical)
• Kinetic doing work (electrical, mechanical,
  radiant)
• Exergonic endergonic reactions

5
Composition of Matter

• 92 naturally occurring elements (112 known,
  113-118 are alleged)
• Living organisms require about 26 of these
  elements (table 2.1, p.28)
• About 96 (by mass) comes from Oxygen (O),
  Carbon (C), Hydrogen (H), and Nitrogen (N)

6
Atoms

• smallest complete unit of an element
• Composed of dozens of subatomic particles, but we
  are only concerned with THREE!

Subatomic Particle Charge Location What it tells you!
Proton Nucleus Identity of atom, mass
Neutron 0 Nucleus Isotope, mass
Electron - Surrounds nucleus Properties of atom, negligible mass
7
Identifying Elements

• Atomic number
• equal to the number of protons in an atom (
  electrons in neutral atom!)
• Atomic mass
• sum of the masses of all the protons neutrons
  contained in nucleus

8
Isotopes

• atoms of same element with a different mass (due
  to neutrons) but same chemical properties
• Ex. C-12 and C-14
• Radioactive isotopes used in many medical tests
  to tag biological molecules to be followed or
  traced
• i.e. PET scans, I-131 for thyroid activity,
  destroying localized cancers (Ra, Co, etc.)

9
Ions

• Charged particles
• Form ionic bonds
• Cations ()
• Anions (-)

10
Find the Face (in the Beans)
11
Chemical Bonds

• Transfer or share electrons in order to fill
  their valence shell (stability)
• All atoms want 8 e- in their valence shell
  (except H He)
• Ionic bond transfer electrons
• Covalent bond share electrons
• Nonpolar shares electrons equally
• Polar shares electron unequally

12
Chemical Bonding

• Due to electronegativity
• How much an atom in a bond pulls electrons to
  itself
• Ionic gt1.7
• Polar covalent 0.4-1.7
• Covalent lt0.4

13
Hydrogen Bonding

• Weak bonds
• attraction of H to partial negative charge
• Example polar covalent bonds between oxygen and
  hydrogen

14
Molecular Formula

• represents the numbers and types of atoms in a
  molecule
• Ex. H2O , C6H12O6

15
Chemical Reactions

• Metabolism sum of all chemical reactions in the
  body
• Synthesis (anabolism) A B AB
• Energy absorbing
• i.e. growth, repair, protein synthesis
• Decomposition (catabolism) AB A B
• Energy releasing
• i.e. digestion of foods, breakdown of glycogen in
  liver to produce glucose
• Single replacement AB C AC B
• Double replacement AB CD AD CB

16
Rate of Chemical Reactions

• Temperature ( temp increases collisions)
• Concentration of reactants ( number faster,
  more collisions)
• Particle size (smaller faster, more collisions)
• Presence of catalysts
• Affect rate of reaction without being changed by
  reaction
• Biological catalysts enzymes (proteins)
• Shape matters! Like a puzzle piece

17
Biochemistry

• Inorganic compounds lack carbon (with few
  exceptions)
• Small, simple molecules
• Water, salts, many acids
• bases
• Organic compounds carbon-containing compounds
• Large covalently bonded molecules
• Carbohydrates, lipids, proteins, nucleic acids

18
Inorganic Compounds

• Water
• High heat capacity
• Absorbs releases large amounts of heat
• Prevents sudden changes in body temperature
  (homeostasis!)
• Polarity/solvent properties
• universal solvent
• Chemical reactions depend on solvent
• Transport/exchange medium
• Lubrication (synovial fluid in joints)
• Chemical reactivity (hydrolysis reactions)
• Cushioning
• Protective (CSF, amniotic fluid)

19
(No Transcript)
20
Inorganic Compounds

• Oxygen
• used to release energy from glucose
• Carbon dioxide
• waste of metabolic processes

21
Inorganic Compounds

• Salts
• Ionic compound containing cations other than H
  and anions other than OH-
• Vital to body functions
• K Na essential for nerve function, Fe2 is
  essential for hemoglobin, Cl-, Ca, Mg, PO4-,
  CO3-, etc.
• All salts are electrolytes (substances that
  conduct an electrical current in solvent)
• Release ions when dissolved in water
• Functions in Table 2.1, page 28

22
Inorganic Compounds

• Acids Bases
• Electrolytes
• Acids
• Release H ions in solution
• proton donors
• HCL, acetic acid, carbonic acid
• Bases
• Release OH- ions in solution
• proton acceptors
• HCO3- (important base in blood)

23

• pH scale measures hydrogen ion concentration
• pH 7 neutral
• pH gt7 basics (more OH- than H)
• pH lt7 acidic (more H than OH-)
• Normal blood pH for humans is 7.35 to 7.45
• If gt , alkalosis
• If lt , acidosis
• Buffers- maintain pH

24
Organic Compounds
Carbohydrates
Lipids
Proteins
Nucleic Acids
25
Carbohydrates

• sugars, starches, glycogen, cellulose
• 2-3 body weight
• Plants- starches and cellulose (cannot digest)
• Animals- source of energy- stored as glycogen

26
Carbohydrates

• Monosaccharides 3 to 7 carbons
• Ex. Glucose, fructose, galactose

Many C6H12O6

• Carbohydrate
• utilized by the
• cell

fructose
27
Carbohydrates

• Disaccharides 2 monosaccharides combine by
  dehydration synthesis (condensation)
• Ex. Sucrose
• Broken apart by hydrolysis (add water)

28
Carbohydrates

• Polysacchride 10-100s of monos
• Ex. starch

29
Lipids

• 18-25 in lean adults
• Contain C, H, O - neutral
• Fats- concentrated energy stored in adipose
  tissue

30
Lipids

• Triglycerides Glycerol 3 fatty acids
• Monounsaturated- one double bond
• Polyunsaturated- more than one double bond
• Saturated- no double bonds

liquid
solid
31
Lipids

• Phospholipids- polar head and 2 non-polar tails
  (membrane)

32
Lipids

• Steroids- cholesterol, sex hormones, cortisol,
  etc.

cholesterol
testosterone
33
Proteins

• 12-18 in lean adults
• Structural and physiological enzymes
• Made of amino acids (20)- held by peptide bonds
• 3D shape held by H-bonds (denatured with heat)

34
Nucleic Acids

• Base sugar phosphate
• DNA and RNA
• ATP- provides energy for the cell

RNA
ATP
DNA
35
Isomers

• molecules with the same chemical formula and with
  the same kinds of bonds between atoms, but in
  which the atoms are arranged differently.
• share similar if not identical properties in most
  chemical contexts.

36
Different molecular and chemical properties!
37
Are these globes moving?