Biology Ch. 1 X

• Biology is the study of life. It unifies much of natural science.

• Life is constrained by the properties of chemistry and physics

• science is becoming more interdisciplinary

• Characteristics of all Living things

  1. Cellular Organization (prokaryote and eukaryote)
  2. Ordered Complexity (metabolic pathways)
  3. Sensitivity to Environment (react/adapt)
  4. Growth, Development, and Reproduction (fission)
  5. Energy Utilization (reactions in a cell- exergonic)
  6. Homeostasis (physiological responses that regulate normal conditions)
  7. Evolutionary Adaptation (change overtime)

• Hierarchical organization of living systems

  • cellular level is the smallest
  • cell-tissue-organ-organ system-organism-population-community -ecosystem-biosphere
  • Population: particular species in a particular place
  • Community: interacting population
  • Ecosystem: community plus physical environment
  • Biosphere: all ecosystems together (Earth)Biosphere: all ecosystems together (Earth)

• Nature of Science

  • aims to understand the world through observation and reasoning.
  • As Specific as possible
  • Inductive Reasoning: from specific ideas to general ideas

  ex: establishing a cell theory

  • Deductive Reasoning: from general to specific ideas

• Independent Variable: the one that we change

• Dependent Variable: result or what you measure

• Scientific Theory- elevating conclusions to a level of theory

• Evolution Theory: common ancestor an adapted

• Biogenesis Theory: life only comes from life

• Gene Theory: organisms have coded info that determine form, function and to some extent behavior

• Darwin was not the first to propose evolution

• Darwins contribution was a mechanism

• Natural selection: is a mechanism for evolution; variation of a feature, certain versions are advantageous; it is heritable

• We must have energy to exist

• humans- food- sun- photosyntesis

• Genome: entire set of DNA instructions

• Gene: particular segment of DNA or discrete unit of inheritance

• CENTRAL DOGMA

• Reductionism: the general approach of biochemistry

• Basic Research: teachers etc

• Applied Research: research used from those teachers

Chapter 2

• Atoms are composed of protons neutrons and electrons
• APE MAN (Atomic Number, Element, Atomic Mass)
  • Electrons: negatively charged particles located in orbitals
  • Neutral atoms have the same number of electrons and protons
• Ions: charged particle electrons change
• Atomic Number: equal to the number of protons
• Element: can’t be broken down into another substance by ordinary means
• Atomic Mass: sum of protons and neutrons
• Cations (cat eyes)
• Anion (ant)
• Isotopes: atoms of a single element that possess different numbers of neutrons
• Radioactive isotopes are unstable
• Nucleus is center of an atom ( DNA inside nucleus)

Electron Arrangement

• energy levels

  KLM (k is inner) K-2 L-8 M-8

• If an atom has a full outer shell it is non reactive

Redox

• LEO says GER

Oxidation: lose electron

Reduction: gain electron

• valence electrons: outer most shell
• Inert: atoms outer most level is full
• Octet rule: must have 8

CHON

• carbon hydrogen oxygen nitrogen make up 96.3 % of body
• Molecule: group of 2 or more atoms held together in a stable association
• Compounds: molecule containing more than one element

all compounds are molecules but not all molecules are compounds

Bonds

• Ionic bonds: formed by the attraction of oppositely charged ions
• Loses an electron to have a positive charge
• Gains an electron to have a negative charge

electrical attraction of water molecules can disrupt forces holding ions together

• Covalent Bonds: form when atoms share 2 or more valence electrons
• Strength of a covalent bond depends on number of bonds present

Electronegativity