General Biology
Chapters 1-8
Lecture and Textbook Notes
Chapters 1 & 2
--------------------------------Lecture: Chemical Context of Life-------------------------
● Emergent Properties: result from the interactions of smaller things within a system
● Reductionist approach: studies the isolated components in a system
Cell: the smallest unit of organization that can perform all life processes
● Membrane bound
● Bacteria and archaea- prokaryotic
● Eukarya- eukaryotic
Eukaryotes
● DNA in the nucleus
● Larger
● Membrane enclosed organelles
● Eukarya
Prokaryotes
● No nucleus
● Smaller
● No membrane enclosed organelles
● Bacteria and archaea
DNA: long strands of molecules that contain genes
● Genes: units of inheritance, encode information for building molecules within the cell
Evolution: accounts for unity and diversity of life
● Concept that living organisms are modified descendents of common ancestors
● Natural selection - the organisms best fit for an environment survive and reproduce
● Taxonomy: classifying the diversity of life
● Two part name: Genus species
● Unity in the diversity of life
○ DNA is common to all organisms
○ Unity in cell structure
,Domains of life
● Bacteria
○ Diverse and widespread prokaryotes
○ Peptidoglycan cell walls
● Archaea
○ Prokaryotes that live in extreme environments
○ No peptidoglycan
● Eukarya
○ Eukaryotic cells
○ Some with and without cell walls
Energy flows through an ecosystem in one direction. It enters as light and leaves as heat
Feedback regulation
● Interaction between components that make up a living organism are crucial
● Feedback regulation is when the output of a process regulates that process
● Negative feedback: the response reduces the initial stimulus
○ Ex- insulin and glucose
● Positive feedback: the end product speeds up production
Science basics:
● Hypothesis: guess of how something works
● Theory: broader, supported by evidence
● Molecule - 2 atoms
● Compound - 2 elements
● CHON: most important elements for life
● Trace element: required by an organism but in small quantities
Chapters 2 & 3
-----------------------------------Lecture: Life and Chemistry-----------------------------
Energy Levels of Electrons
● Energy: the capacity to cause change
● Potential energy: the energy that matter has because of its location
● An electron's potential energy is determined by its electron shells
○ Farther shells have higher energy levels
○ If we move electrons to different shells we put different energy in that system that
can be released
● Orbitals: 3D space where an electron shell spends most of its time
● Valence electrons: Electrons in the outermost shell
, ○ Determines the chemical behavior of an atom
○ Electrons closer to the nucleus tend to stay there
○ Elements with a full valence shell are chemically inert
Chemical Bonds: bonds that stabilize the interaction between atoms
Covalent Bond: the sharing of a pair of valence electrons by two atoms
● Shared electrons count as part of each atoms valence shell
● A molecule consists of two or more atoms held together by covalent bonds
● Bonding capacity is determined by the atom's valence
● Nonpolar: atoms share the electrons equally
● Polar: one atom is more electronegative and the atoms do not share equally
● Electronegativity: an atom's attraction for the electrons in a covalent bond
Hydrogen Bonds: When a hydrogen bond covalently bonded to one electronegative atom is also
attracted to another electronegative atom
Hydrophobic forces: water fearing bonds. Interaction between molecules that cannot hydrogen
bond.
Van Der Waals forces: molecules so close together that they generate weak interactions.
Collectively can be strong
- Ex: Geckos toe hairs and wall
Ionic Bonds: atoms sometimes strip electrons from their bonding partners
● Cation: a positively charged ion
● Anion: a negatively charged ion
● Compounds are formed by ionic bonds
Chapter 4
-----------------------------Lecture: Water Carbon and Chemistry-----------------------
Chemical Reactions: they make and break bonds
● Reactants: starting molecules
● Products: ending molecules
● Two opposite headed arrows indicate that a chemical reaction is reversible
● Chemical equilibrium: when the forward and reverse reactions occur at the same rate
○ At equilibrium the relative concentrations of reactants and products do not change
Chapters 1-8
Lecture and Textbook Notes
Chapters 1 & 2
--------------------------------Lecture: Chemical Context of Life-------------------------
● Emergent Properties: result from the interactions of smaller things within a system
● Reductionist approach: studies the isolated components in a system
Cell: the smallest unit of organization that can perform all life processes
● Membrane bound
● Bacteria and archaea- prokaryotic
● Eukarya- eukaryotic
Eukaryotes
● DNA in the nucleus
● Larger
● Membrane enclosed organelles
● Eukarya
Prokaryotes
● No nucleus
● Smaller
● No membrane enclosed organelles
● Bacteria and archaea
DNA: long strands of molecules that contain genes
● Genes: units of inheritance, encode information for building molecules within the cell
Evolution: accounts for unity and diversity of life
● Concept that living organisms are modified descendents of common ancestors
● Natural selection - the organisms best fit for an environment survive and reproduce
● Taxonomy: classifying the diversity of life
● Two part name: Genus species
● Unity in the diversity of life
○ DNA is common to all organisms
○ Unity in cell structure
,Domains of life
● Bacteria
○ Diverse and widespread prokaryotes
○ Peptidoglycan cell walls
● Archaea
○ Prokaryotes that live in extreme environments
○ No peptidoglycan
● Eukarya
○ Eukaryotic cells
○ Some with and without cell walls
Energy flows through an ecosystem in one direction. It enters as light and leaves as heat
Feedback regulation
● Interaction between components that make up a living organism are crucial
● Feedback regulation is when the output of a process regulates that process
● Negative feedback: the response reduces the initial stimulus
○ Ex- insulin and glucose
● Positive feedback: the end product speeds up production
Science basics:
● Hypothesis: guess of how something works
● Theory: broader, supported by evidence
● Molecule - 2 atoms
● Compound - 2 elements
● CHON: most important elements for life
● Trace element: required by an organism but in small quantities
Chapters 2 & 3
-----------------------------------Lecture: Life and Chemistry-----------------------------
Energy Levels of Electrons
● Energy: the capacity to cause change
● Potential energy: the energy that matter has because of its location
● An electron's potential energy is determined by its electron shells
○ Farther shells have higher energy levels
○ If we move electrons to different shells we put different energy in that system that
can be released
● Orbitals: 3D space where an electron shell spends most of its time
● Valence electrons: Electrons in the outermost shell
, ○ Determines the chemical behavior of an atom
○ Electrons closer to the nucleus tend to stay there
○ Elements with a full valence shell are chemically inert
Chemical Bonds: bonds that stabilize the interaction between atoms
Covalent Bond: the sharing of a pair of valence electrons by two atoms
● Shared electrons count as part of each atoms valence shell
● A molecule consists of two or more atoms held together by covalent bonds
● Bonding capacity is determined by the atom's valence
● Nonpolar: atoms share the electrons equally
● Polar: one atom is more electronegative and the atoms do not share equally
● Electronegativity: an atom's attraction for the electrons in a covalent bond
Hydrogen Bonds: When a hydrogen bond covalently bonded to one electronegative atom is also
attracted to another electronegative atom
Hydrophobic forces: water fearing bonds. Interaction between molecules that cannot hydrogen
bond.
Van Der Waals forces: molecules so close together that they generate weak interactions.
Collectively can be strong
- Ex: Geckos toe hairs and wall
Ionic Bonds: atoms sometimes strip electrons from their bonding partners
● Cation: a positively charged ion
● Anion: a negatively charged ion
● Compounds are formed by ionic bonds
Chapter 4
-----------------------------Lecture: Water Carbon and Chemistry-----------------------
Chemical Reactions: they make and break bonds
● Reactants: starting molecules
● Products: ending molecules
● Two opposite headed arrows indicate that a chemical reaction is reversible
● Chemical equilibrium: when the forward and reverse reactions occur at the same rate
○ At equilibrium the relative concentrations of reactants and products do not change
