Transcript Ch.2-3 & 3 Notes - Green Local Schools

Biochemistry
Ch.2-3 & 3
(2-3) Water Structure
• O is -, while the H’s are +
– Uneven distribution of charge
O
H
H
Polar vs. Nonpolar
• Polar: 1 end is + & other is –
– “Like dissolves like”
– Charges help break apart other cmpds
• Nonpolar: even distribution of charge
Hydrogen Bond
• Weak force of attraction b/w a H atom
in 1 molecule & a negatively charged
atom in a 2nd molecule
Properties of Water
• Cohesion: attractive force b/w like
particles
– Ex: water attracts to itself & forms “skin”
• Adhesion: attractive force b/w unlike
substances
– Ex: water clinging to edges of a glass
Capillarity
• Rxn of a liquid surface w/ a solid
– Combine adhesion & cohesion
• Allows water to creep up the interior of
a narrow vessel
– Ex: water flows up a flower’s
stem
Temp. Moderation
• Water must gain or lose a large amt.
of E for its temp. to change
• Helps cells maintain homeostasis
(3-1) Carbon Compounds
• Organic cmpds: contain C atoms
bonded to other elements such as H,
O, & N
• Functional groups: influence
properties of a molecule
– Ex: -NH2 for amino acids
Building Blocks
• Molecules are made up of smaller parts
called monomers
• 2 = dimer
• 3 or more = polymer
Making a Macromolecule
• Condensation rxn: formation of larger
molecules by removing a H+ from 1
monomer & a OH- from the other
monomer
• H+ & OH- combine to form H2O
Breaking a Macromolecule
• Hydrolysis rxn: the use of water to break
polymers back into monomers
– Reverse of condensation rxn
E Currency
• Life requires a constant supply of E
• ATP (adenosine triphosphate)
– Releases E when broken down
(3-2) Molecules of Life
•
•
•
•
Carbohydrates - monosaccharides
Proteins – amino acids
Lipids – fatty acids
Nucleic Acids - nucleotides
Nutrition Facts
• Lipids
• Sugars
• Amino acids
1. Carbohydrates
• Monosaccharide = monomer
– Glucose
• Disaccharide = 2 monomers
– Table sugar
• Polysaccharide = 3+ monomers
– Starch, cellulose, glycogen
2. Protein
• Amino Acid = monomer
– 20 different types
• Peptide bond holds amino acids
together
• Dipeptide & Polypeptide = chains of
amino acids
Most Diverse Group of Molecules
Enzymes
• Most are proteins
– ase ending
• Protease (digests proteins)
• Catalysts
– Speed up rxns by reducing activation E
(essential for cell function)
• Reduce efficiency if change in T or pH
– Active site changes shape (lock & key)
pH
• Acids: inc. the H+ conc.
• Bases: inc. the OH- conc.
• pH = -log[H+]
– As [H+] inc., pH dec. (10 fold)
• pH scale: 1-14
– Acidic = <7
– Neutral = 7
– Basic = >7
3. Lipids
• Fatty acids = monomer
– Hydrophilic (water loving): polar head
– Hydrophobic (water fearing): nonpolar tail
• Store the most E
Complex Lipids
• Fats: triglycerides
– Saturated – bad
– Unsaturated – good
• Phospholipids: cell barrier
– Waxes: protective covering
• Steroids: cholesterol, hormones
4. Nucleic Acids
• Nucleotide = monomer
• Store impt. info in the cell & make
proteins
– DNA & RNA