Exam Study Notes

Water Properties

• Attraction between water molecules: Polar molecules exhibit hydrogen bonding.

• Table salt (NaCl) dissolves in water: Ions attracted to opposite charges.

• Adhesion: Water sticks to a surface.

• Cohesion: Water molecules attract each other.

• Surface Tension: Caused by cohesion and adhesion.

• Polarity: Makes hydrogen bonds possible, great solvent.

• Solid (ice): Slow-moving molecules.

• Liquid: Molecules move more freely.

• Ice is less dense than liquid water.

Experiment Variables

• Dependent variable: Plant height.

• Independent variable: Ammonium nitrate.

Molecules in the Cell Membrane

• Lipids: separate internal/external environments.

Atoms in Molecules

• Amino acids: Carbon, oxygen, nitrogen, hydrogen.

• Fatty acids: Carbon, oxygen, hydrogen.

• Key difference: Amino acids contain nitrogen.

Carbohydrates

• Macromolecules for energy.

• Monosaccharides are building blocks.

• Components: Carbon, hydrogen, oxygen.

Aquatic Birds and Lipids

• Waxy substances repel water, mostly lipids.

Carbohydrates in Diet

• Broken down in cells for energy.

Enzyme Activity and pH

• Optimum pH: Highest enzyme activity.

Macromolecules

• Carbohydrates: Monosaccharides, C, H, O.

• Proteins: Amino acids, C, H, O, N, sometimes S.

• Nucleic Acids: Nucleotides, C, O, H, N, P.

• Lipids: Fatty acids/glycerol, C, H, O.

Elements and Compounds

• Elements: Sodium (Na), chlorine (Cl).

• Compound: Sodium chloride (NaCl).

• Solution: Table salt dissolves in water.

Lactose

• Sugar in dairy products.

• Disaccharide: glucose and galactose.

• Carbohydrate.

Lactose Intolerance

• Difficulty digesting dairy products.

• Enzymes speed up reactions.

Solubility

• Sugar and salt are polar; fats and oils are nonpolar.

• Nonpolar substances least likely to dissolve.

Cell Structure and Function

• Nucleolus: Makes ribosomes.

• Lysosomes: Digest bacteria.

• Nucleus: Contains DNA.

• Cell membrane: Lets substances pass, maintains homeostasis.

• Chloroplasts: Photosynthesis.

• Cell Theory: All living things are cells; cells are basic units; cells come from cells.

• Cytoplasm: Gel-like fluid.

• Robert Hooke: First to see cells.

• Cell wall: Outer boundary.

• Mitochondria: Power.

Cell Membrane Transport

• Ions: Movement controlled by signals.

• Manufacturing: Nucleus, nucleolus, rough ER.

• Prokaryotes: No membrane-bound nucleus.

• Support: Cell wall, central vacuole.

• Organelles: Golgi, ER, lysosomes, vacuoles.

• Eyepiece: Microscope part near eye.

• Diaphragm: Controls light beam.

• Cytoplasm: Polarity and hydrogen bonds.

Cell Transport

• Diffusion: High to low concentration.

• Cell Equilibrium: Balance.

• Molecules Inside: Carbohydrates(energy), Proteins(transport), Phospholipids(protection).

• Oxygen enters by diffusion.

• Facilitated diffusion: Requires carrier protein, no energy.

• Active transport requires energy.

• Hydrophobic portion of phospholipid bilayer.

• Hypotonic swells, hypertonic shrinks cells.

• Freshwater fish in ocean: cells shrink, fish dies.

Cell Quiz

• Plant cell in 12% salt: shrinks and dies.

• IV fluids: isotonic (0.9% saline).

• CO2 equilibrium: No net movement.

• Red blood cell in hypertonic: shrinks.

• Equilibrium reached: The cell will get bigger.

Nucleic Acids

• DNA: Thymine (T); RNA: Uracil (U).

Cytosine Content in DNA

• Cytosine 38%: Adenine 12%.

Antiparallel DNA

• 5' to 3' direction runs counter.

Bonds

• Hydrogen bonds hold DNA strands.

E. Coli DNA

• Circular.

Gene Sequence

• DNA makes RNA makes protein.

Sugar in RNA

• Ribose.

Protein Synthesis Location

• Ribosomes in cytoplasm.

Deoxyribose Carbons

• 5 carbons.

Blueprint of Life

• DNA contains plans for building organism.

Nobel Prize

• Watson and Crick: DNA structure.

DNA Molecule

• Complementary sequence: 3'-GCGTACATCGCT-5'

RNA vs DNA

• DNA: genetic information, double helix, thymine.

• RNA: synthesizes proteins, single helix, uracil.

Rosalind Franklin

• Photographed DNA using X-ray crystallography.

DNA

• True: Living things have DNA; sequence of bases determines gene; bases can occur in any order; humans have 23 pairs of chromosomes.

• False: DNA not made of thousands of chromosomes; DNA strand does not contain about 20 nucleotides.

Protein Synthesis Order

• B → E → A → C → D

Molecule Synthesis

• Polypeptide formed by dehydration synthesis.

Biochemical Process

• Occurs in ribosome with mRNA, tRNA, amino acids.

Molecules

• DNA, messenger RNA, transfer RNA, polypeptide.

DNA Molecule

• Letter X: nitrogenous bases joined by hydrogen bonds.

Gene Mutation

• Change in DNA sequence.

mRNA

• AUG for methionine.
  Carries instructions from Nucleus to cytoplasm

DNA molecule

• The diagram represents a molecule of DNA.

Nucleotide

• A, B, and D

Segment of DNA

• 8 nucleotides bonded

DNA strand

ATG-CTG-CGA-TCC-AAT becomes $$TAC-GAC-